National Library of Energy BETA

Sample records for mn al 1970-1974

  1. 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

  2. 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

  3. 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

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Magnetic and transport properties of Mn{sub 2}CoAl oriented films

    SciTech Connect (OSTI)

    Jamer, Michelle E.; Assaf, Badih A.; Devakul, Trithep; Heiman, Don

    2013-09-30

    The structure, magnetic, and transport properties of thin films of the Heusler ferrimagnet Mn{sub 2}CoAl have been investigated for properties related to spin gapless semiconductors. Oriented films were grown by molecular beam epitaxy on GaAs substrates and the structure was found to transform from tetragonal to cubic for increasing annealing temperature. The anomalous Hall resistivity is found to be proportional to the square of the longitudinal resistivity and magnetization expected for a topological Berry curvature origin. A delicate balance of the spin-polarized carrier type when coupled with voltage gate-tuning could significantly impact advanced electronic devices.

  12. 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.

  13. 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.

  14. 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.

  15. Calculations of structural, elastic, electronic, magnetic and phonon properties of FeNiMnAl by the first principles

    SciTech Connect (OSTI)

    U?ur, ?ule; ?yigr, Ahmet

    2014-10-06

    The electronic, elastic and dynamical properties of the quaternary alloy FeNiMnAl have been investigated using a pseudopotential plane wave method within the generalized gradient approximation (GGA). We determined the lattice parameters and the bulk modulus B. In addition, the elastic properties such as elastic constans (C{sub 11}, C{sub 12} and C{sub 44}), the shear modulus G, the young modulus E, the poisson's ratio ? and the B/G ratio are also given. The FeNiMnAl Heusler alloy exhibit a ferromagnetic half-metallic behavior with the total magnetic moment of 4.02 ?{sub B}. The phonon dispersion of FeNiMnAl has been performed using the density functional theory and the direct method with 222 supercell.

  16. Conditions for spin-gapless semiconducting behavior in Mn{sub 2}CoAl inverse Heusler compound

    SciTech Connect (OSTI)

    Galanakis, I.; zdo?an, K.; ?a??o?lu, E.; Blgel, S.

    2014-03-07

    Employing ab initio electronic structure calculations, we investigate the conditions for spin-gapless semiconducting (SGS) behavior in the inverse Mn{sub 2}CoAl Heusler compound. We show that tetragonalization of the lattice, which can occur during films growth, keeps the SGS character of the perfect cubic compound. On the contrary, atomic swaps even between sites with different local symmetry destroy the SGS character giving rise to a half-metallic state. Furthermore, the occurrence of Co-surplus leads also to half-metallicity. Thus, we propose that in order to achieve SGS behavior during the growth of Mn{sub 2}CoAl (and similar SGS Heusler compounds) thin films, one should minimize the occurrence of defects, while small deformations of the lattice, due to the lattice mismatch with the substrate, do not play a crucial role.

  17. Magneto-transport properties of oriented Mn{sub 2}CoAl films sputtered on thermally oxidized Si substrates

    SciTech Connect (OSTI)

    Xu, G. Z.; Du, Y.; Zhang, X. M.; Liu, E. K.; Wang, W. H. Wu, G. H.; Zhang, H. G.

    2014-06-16

    Spin gapless semiconductors are interesting family of materials by embracing both magnetism and semiconducting due to their unique band structure. Its potential application in future spintronics requires realization in thin film form. In this Letter, we report fabrication and transport properties of spin gapless Mn{sub 2}CoAl films prepared on thermally oxidized Si substrates by magnetron sputtering deposition. The films deposited at 673 K are well oriented to (001) direction and display a uniform-crystalline surface. Magnetotransport measurements on the oriented films reveal a semiconducting-like resistivity, small anomalous Hall conductivity, and linear magnetoresistance representative of the transport signatures of spin gapless semiconductors. The magnetic properties of the films have also been investigated and compared to that of bulk Mn{sub 2}CoAl, showing small discrepancy induced by the composition deviation.

  18. Atomic moments in Mn2CoAl thin films analyzed by X-ray magnetic circular dichroism

    SciTech Connect (OSTI)

    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.

  19. Atomic moments in Mn2CoAl thin films analyzed by X-ray magnetic circular dichroism

    SciTech Connect (OSTI)

    Jamer, M.; Sterbinsky, G.; Assaf, B.; Arena, D.; 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. 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. (auth)

  20. Functioning mechanism of AlF3 coating on the Li- and Mn-rich cathode materials

    SciTech Connect (OSTI)

    Zheng, Jianming; Gu, Meng; Xiao, Jie; Polzin, Bryant; Yan, Pengfei; Chen, Xilin; Wang, Chong M.; Zhang, Jiguang

    2014-11-25

    Li- and Mn-rich (LMR) material is a very promising cathode for lithium ion batteries because of their high theoretical energy density (~900 Wh kg-1) and low cost. However, their poor long-term cycling stability, voltage fade, and low rate capability are significant barriers hindered their practical applications. Surface coating, e.g. AlF3 coating, can significantly improve the capacity retention and enhance the rate capability. However, the fundamental mechanism of this improvement and the microstructural evolution related to the surface coating is still not well understood. Here, we report systematic studies of the microstructural changes of uncoated and AlF3-coated materials before and after cycling using aberration-corrected scanning/transmission electron microscopy and electron energy loss spectroscopy. The results reveal that surface coating can reduce the oxidation of electrolyte at high voltage, thus suppressing the accumulation of SEI layer on electrode particle surface. Surface coating also enhances structural stability of the surface region (especially the electrochemically transformed spinel-like phase), and protects the electrode from severe etching/corrosion by the acidic species in the electrolyte, therefore limiting the degradation of the material. Moreover, surface coating can alleviate the undesirable voltage fade by minimize layered-spinel phase transformation in the bulk region of the materials. These fundamental findings may also be widely applied to explain the functioning mechanism of other surface coatings used in a broad range of electrode materials.

  1. Electronic structure, magnetism, and antisite disorder in CoFeCrGe and CoMnCrAl quaternary Heusler alloys

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

    Enamullah, .; Venkateswara, Y.; Gupta, Sachin; Varma, Manoj Raama; Singh, Prashant; Suresh, K. G.; Alam, Aftab

    2015-12-10

    In this study, we present a combined theoretical and experimental study of two quaternary Heusler alloys CoFeCrGe (CFCG) and CoMnCrAl (CMCA), promising candidates for spintronics applications. Magnetization measurement shows the saturation magnetization and transition temperature to be 3 μB, 866 K and 0.9 μB, 358 K for CFCG and CMCA respectively. The magnetization values agree fairly well with our theoretical results and also obey the Slater-Pauling rule, a prerequisite for half metallicity. A striking difference between the two systems is their structure; CFCG crystallizes in fully ordered Y-type structure while CMCA has L21 disordered structure. The antisite disorder adds amore » somewhat unique property to the second compound, which arises due to the probabilistic mutual exchange of Al positions with Cr/Mn and such an effect is possibly expected due to comparable electronegativities of Al and Cr/Mn. Ab initio simulation predicted a unique transition from half metallic ferromagnet to metallic antiferromagnet beyond a critical excess concentration of Al in the alloy.« less

  2. Electronic structure, magnetism, and antisite disorder in CoFeCrGe and CoMnCrAl quaternary Heusler alloys

    SciTech Connect (OSTI)

    Enamullah, .; Venkateswara, Y.; Gupta, Sachin; Varma, Manoj Raama; Singh, Prashant; Suresh, K. G.; Alam, Aftab

    2015-12-10

    In this study, we present a combined theoretical and experimental study of two quaternary Heusler alloys CoFeCrGe (CFCG) and CoMnCrAl (CMCA), promising candidates for spintronics applications. Magnetization measurement shows the saturation magnetization and transition temperature to be 3 μB, 866 K and 0.9 μB, 358 K for CFCG and CMCA respectively. The magnetization values agree fairly well with our theoretical results and also obey the Slater-Pauling rule, a prerequisite for half metallicity. A striking difference between the two systems is their structure; CFCG crystallizes in fully ordered Y-type structure while CMCA has L21 disordered structure. The antisite disorder adds a somewhat unique property to the second compound, which arises due to the probabilistic mutual exchange of Al positions with Cr/Mn and such an effect is possibly expected due to comparable electronegativities of Al and Cr/Mn. Ab initio simulation predicted a unique transition from half metallic ferromagnet to metallic antiferromagnet beyond a critical excess concentration of Al in the alloy.

  3. Al{sub 70}Pd{sub 21.5}Mn{sub 8.5}: A quasicrystal showing the de haas-van Alphen effect

    SciTech Connect (OSTI)

    Haanappel, E.G. [National High Magnetic Field Laboratory, Los Alamos, NM (United States). Pulsed Field Facility; Kycia, S.W.; Harmon, B.N.; Canfield, P.C.; Goldman, A.I. [Iowa State Univ., Ames, IA (United States). Ames Lab.; Rabson, D.A.; Thompson, J.D.; Mueller, F.M. [Los Alamos National Lab., NM (United States)

    1995-07-01

    We have measured the de Haas-van Alphen effect in the icosahedral quasicrystal Al{sub 70}Pd{sub 21.5}Mn{sub 8.5}. We have found two well-defined frequencies with the magnetic field parallel to a five-fold axis, and two different ones with the field parallel to a two-fold axis. On increasing the temperature, the amplitude of the oscillations substantially decreased, suggesting that the carriers have large masses.

  4. The site occupation and valence of Mn ions in the crystal lattice of Sr{sub 4}Al{sub 14}O{sub 25} and its deep red emission for high color-rendering white light-emitting diodes

    SciTech Connect (OSTI)

    Chen, Lei; Xue, Shaochan; Chen, Xiuling; Bahader, Ali; Deng, Xiaorong; Zhao, Erlong; Jiang, Yang; Chen, Shifu; Chan, Ting-Shan; Zhao, Zhi; Zhang, Wenhua

    2014-12-15

    Highlights: Different valences of Mn ions in Sr{sub 4}Al{sub 14}O{sub 25} were identified using XANES and EPR. Red luminescence was attributed to Mn{sup 4+} occupying the center of AlO{sub 6} octahedron. The Mn{sup 3+} incorporated in the center of AlO{sub 4} tetrahedron was non-luminescent. The bond-valence theory was used to analyze the effective valences of cations. A white LED device with CRI up to Ra 93.23 was packaged by using the red phosphor. - Abstract: The synthesis and component of red phosphor, Sr{sub 4}Al{sub 14}O{sub 25}: Mn, were optimized for application in white light-emitting diodes. The microstructure and morphology were investigated by the X-ray diffraction and scanning electron microscopy. Different valences of Mn ions in Sr{sub 4}Al{sub 14}O{sub 25} were discriminated using the electron paramagnetic resonance and X-ray absorption near-edge structure spectroscopy techniques. The bond-valence theory was used to analyze the effective valences of Sr{sup 2+} and Al{sup 3+} in Sr{sub 4}Al{sub 14}O{sub 25}. As a result, the strong covalence of Al{sup 3+} in the AlO{sub 4} tetrahedron other than in the AlO{sub 6} octahedron is disclosed. The deep red emission is attributed to Mn{sup 4+} occupying the center of AlO{sub 6} octahedron. The mechanism of energy transfer is mainly through dipoledipole interaction, revealed by the analyses of critical distance and concentration quench. A high color rendering white LED prototype with color-rendering index up to Ra 93.23 packaged by using the red phosphor demonstrates its applicability.

  5. Effects of Intercritical Annealing Temperature on Mechanical Properties of Fe-7.9Mn-0.14Si-0.05Al-0.07C Steel

    SciTech Connect (OSTI)

    Zhao, Xianming; Shen, Yongfeng; Qiu, Lina; Liu, Yandong; Sun, Xin; Zuo, Liang

    2014-12-09

    A medium Mn steel has been designed to achieve an excellent combination of strength and ductility based on the TRIP (Transformation Induced Plasticity) concept for automotive applications. Following six passes of hot rolling at 850 °C, the Fe-7.9Mn-0.14Si-0.05Al-0.07C (wt.%) steel was warm-rolled at 630 °C for seven passes and subsequently air cooled to room temperature. The sample was subsequently intercritically annealed at various temperatures for 30 min to promote the reverse transformation of martensite into austenite. The obtained results show that the highest volume fraction of austenite is 39% for the sample annealed at 600 °C. This specimen exhibits a yield stress of 910 MPa and a high ultimate tensile stress of 1600 MPa, with an elongation-to-failure of 0.29 at a strain rate of 1 × 10⁻³/s. The enhanced work-hardening ability of the investigated steel is closely related to martensitic transformation and the interaction of dislocations. Especially, the alternate arrangement of acicular ferrite (soft phase) and ultrafine austenite lamellae (50–200 nm, strong and ductile phase) is the key factor contributing to the excellent combination of strength and ductility. On the other hand, the as-warm-rolled sample also exhibits the excellent combination of strength and ductility, with elongation-to-failure much higher than those annealed at temperatures above 630 °C.

  6. Quantum-mechanical simulation of the IR reflectance spectrum of Mn{sub 3}Al{sub 2}Si{sub 3}O{sub 12} spessartine

    SciTech Connect (OSTI)

    Ferrari, A. M.; Demichelis, R.; Meyer, A.; Maschio, L.; Dovesi, R.; Pascale, F.

    2015-01-22

    The reflectance spectrum of one member of the garnet family, Mn{sub 3}Al{sub 2}Si{sub 3}O{sub 12} spessartine, was computed at the ab initio level with an all electron Gaussian type basis set and the B3LYP Hamiltonian. The static high frequency dielectric constant was obtained by applying the Coupled Perturbed Kohn Sham scheme as implemented in the CRYSTAL code; the Hessian matrix was evaluated numerically starting from the analytical gradients of the total energy with respect to the Cartesian coordinates of the atoms; the oscillator strengths were computed from well localized Wannier functions. An excellent agreement was obtained with the corresponding experimental spectrum, the exception being the very low frequency region.

  7. Al

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

    on the way to the drip line .... 31 Al 28 Mg 32 Si 12 B + 18 O 30 Al* (-pn) 28 Mg 15 C + 18 O 33 Si* (-pn) 31 Al 16 N + 18 O 34 P* (-pn) 32 Si 15 C 10 7 s...

  8. Effects of Intercritical Annealing Temperature on Mechanical Properties of Fe-7.9Mn-0.14Si-0.05Al-0.07C Steel

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

    Zhao, Xianming; Shen, Yongfeng; Qiu, Lina; Liu, Yandong; Sun, Xin; Zuo, Liang

    2014-12-09

    A medium Mn steel has been designed to achieve an excellent combination of strength and ductility based on the TRIP (Transformation Induced Plasticity) concept for automotive applications. Following six passes of hot rolling at 850 °C, the Fe-7.9Mn-0.14Si-0.05Al-0.07C (wt.%) steel was warm-rolled at 630 °C for seven passes and subsequently air cooled to room temperature. The sample was subsequently intercritically annealed at various temperatures for 30 min to promote the reverse transformation of martensite into austenite. The obtained results show that the highest volume fraction of austenite is 39% for the sample annealed at 600 °C. This specimen exhibits amore » yield stress of 910 MPa and a high ultimate tensile stress of 1600 MPa, with an elongation-to-failure of 0.29 at a strain rate of 1 × 10⁻³/s. The enhanced work-hardening ability of the investigated steel is closely related to martensitic transformation and the interaction of dislocations. Especially, the alternate arrangement of acicular ferrite (soft phase) and ultrafine austenite lamellae (50–200 nm, strong and ductile phase) is the key factor contributing to the excellent combination of strength and ductility. On the other hand, the as-warm-rolled sample also exhibits the excellent combination of strength and ductility, with elongation-to-failure much higher than those annealed at temperatures above 630 °C.« less

  9. Role of Ce<mn>4mn>+ in the scintillation mechanism of codoped Gd<mn>3mn>Ga<mn>3mn>Al>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.

  10. Ferromagnetism and magneto-transport properties of Mn{sub 0.92}Ca{sub 0.08}As thin film grown on Al{sub 2}O{sub 3}(0001) substrate

    SciTech Connect (OSTI)

    Dung, Dang Duc; Van Thiet, Duong; Anh Tuan, Duong; Cho, Sunglae; Feng, Wuwei

    2014-05-07

    The epitaxial Mn{sub 0.92}Ca{sub 0.08}As thin film was grown on Al{sub 2}O{sub 3}(0001) substrate by molecular beam epitaxy. The Curie temperature (T{sub C}) around 340 K was enhanced with the addition of Ca, compared to that of bulk MnAs (T{sub C} ∼ 318 K). The maxima magnetoresistance, ∼2.08% at 0.7 T, was observed near the critical magnetic transition temperature. Moreover, the giant magnetocaloric effect was found with the maximum magnetic entropy change, ∼200 J/kgK, around 330 K at 5 T.

  11. Soft X-ray absorption spectroscopy of La{sub 0.7}Ca{sub 0.3}Mn{sub 1?X}Al{sub X}O{sub 3} thin films

    SciTech Connect (OSTI)

    Kumar, Manish Choudhary, R. J. Phase, D. M.

    2014-04-24

    Epitaxial thin films of rare earth manganites have generated much attention recently due to their rich phase diagram. The electronic structure of these films is playing a very crucial role and demands a fundamental understanding prior to device fabrication. We have investigated the electronic structure of La{sub 0.7}Ca{sub 0.3}Mn{sub 1?X}Al{sub X}O{sub 3} (X=0, 0.15) epitaxial thin films by soft X-ray absorption spectroscopy technique using the surface sensitive total electron yield (TEY) mode.

  12. Structural Underpinnings of the Enhanced Cycling Stability upon Al-Substitution in LiNi[subscript 0.45]Mn[subscript 0.45]Co[subscript 0.1?y]Al[subscript y]O[subscript 2] Positive Electrode Materials for Li-ion Batteries

    SciTech Connect (OSTI)

    Conry, Thomas E.; Mehta, Apurva; Cabana, Jordi; Doeff, Marca M.

    2012-10-23

    Single-phase LiNi{sub 0.45}Mn{sub 0.45}Co{sub 0.1-y}Al{sub y}O{sub 2} layered oxide materials with 0 {<=} y {<=} 0.10 were prepared using the glycine-nitrate combustion method. Al-substitution has a minimal effect on the defect concentration and rate capability of the materials, but raises the operating voltage and reduces the capacity fade of the materials during prolonged cycling compared to the unsubstituted system. In situ X-ray diffraction suggests the presence of Al has a significant structural impact during battery operation. It acts to limit the changes in lattice parameters observed during electrochemical charging and cycling of the materials. High-resolution X-ray diffraction reveals structural distortions in the transition metal layers of as-synthesized powders with high Al-contents, as well as a structural evolution seen in all materials after cycling.

  13. Structure and Electrochemistry of LiNi1/3Co1/3-yMyMn1/3O2 (M=Ti, Al, Fe) Positive Electrode Materials

    SciTech Connect (OSTI)

    Wilcox, James; Patoux, Sebastien; Doeff, Marca

    2009-01-14

    A series of materials based on the LiNi1/3Co1/3-yMyMn1/3O2 (M = Ti,Al,Fe) system has been synthesized and examined structurally and electrochemically. It is found that the changes in electrochemical performance depend highly on the nature of the substituting atom and its effect on the crystal structure. Substitution with small amounts of Ti4+ (y = 1/12) leads to the formation of a high-capacity and high-rate positive electrode material. Iron substituted materials suffer from an increased antisite defect concentration and exhibit lower capacities and poor rate capabilities. Single-phase materials are found for LiNi1/3Co1/3-yAlyMn1/3O2 when y<_ 1/4 and all exhibit decreased capacities when cycled to 4.3 V. However, an increase in rate performance and cycle stability upon aluminum substitution is correlated with an improved lamellar structure.

  14. BiFeO{sub 3}/La{sub 0.7}Sr{sub 0.3}MnO{sub 3} heterostructures deposited on spark plasma sintered LaAlO{sub 3} substrates

    SciTech Connect (OSTI)

    Pravarthana, D.; Lacotte, M.; David, A.; Prellier, W.; Trassin, M.; Haw Chu, Jiun; Ramesh, R.; Salvador, P. A.

    2014-02-24

    Multiferroic BiFeO{sub 3} (BFO)/La{sub 0.7}Sr{sub 0.3}MnO{sub 3} heterostructured thin films were grown by pulsed laser deposition on polished spark plasma sintered LaAlO{sub 3} (LAO) polycrystalline substrates. Both polycrystalline LAO substrates and BFO films were locally characterized using electron backscattering diffraction, which confirmed the high-quality local epitaxial growth on each substrate grain. Piezoforce microscopy was used to image and switch the piezo-domains, and the results are consistent with the relative orientation of the ferroelectric variants with the surface normal. This high-throughput synthesis process opens the routes towards wide survey of electronic properties as a function of crystalline orientation in complex oxide thin film synthesis.

  15. Ab-initio study of electronic structure and magnetic properties of half-metallic Fe{sub 2}Mn{sub 1−x}V{sub x}Si{sub 0.5}Al{sub 0.5} alloys

    SciTech Connect (OSTI)

    Go, Anna

    2014-11-15

    Ab-initio electronic structure calculations are carried out for quinternary Fe{sub 2}Mn{sub 1−x}V{sub x}Si{sub 0.5}Al{sub 0.5} alloys. When x=0 the alloy is half-metallic ferromagnet, with magnetic moment following the Slater–Pauling rule. Replacement of Mn by V, changes its electronic and magnetic structure. V-doped alloys exhibit half-metallic behavior for x≤0.25. However, even for higher V concentrations, electronic spin polarization is still very high, what makes the alloys interesting for spintronic applications. - Graphical abstract: Densities of states of Fe{sub 2}MnSi{sub 0.5}Al{sub 0.5} and magnetic moments of Fe{sub 2}Mn{sub 1−x}V{sub x}Si{sub 0.5}Al{sub 0.5}. - Highlights: • Fe{sub 2}MnSi{sub 0.5}Al{sub 0.5} is a half-metallic ferromagnet with a minority band gap of 0.49 eV. • Half-metallic band gap is very stable against the change of the lattice parameter. • Half-metallic band gap is obtained for Fe{sub 2}Mn{sub 1−x}V{sub x}Si{sub 0.5}Al{sub 0.5} for x≤0.25. • Electronic spin polarization is very high and equal to at least 95% for x≤0.625. • The main carrier of magnetism of the compound is manganese.

  16. 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.

  17. 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.

  18. 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...

  19. 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.

  20. 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...

  1. ALS Spectrum

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

    ALS Spectrum Print Begun in 2007, ALS Spectrum is a publication that encapsulates the same type of information contained in the ALS Activity Report but in a short, readable,...

  2. ALS@20

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

    tribulations encountered during the construction of the ALS from former Director Jay Marx, current ALS Scientific Director Steve Kevan and Director Roger Falcone talked about...

  3. ALS Spectrum

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

    Spectrum Print Begun in 2007, ALS Spectrum is a publication that encapsulates the same type of information contained in the ALS Activity Report but in a short, readable,...

  4. The influence of the iron content on the reductive decomposition of A{sub 3?x}Fe{sub x}Al{sub 2}Si{sub 3}O{sub 12} garnets (A = Mg, Mn; 0.47 ? x ? 2.85)

    SciTech Connect (OSTI)

    Aparicio, Claudia, E-mail: claudia.aparicio@upol.cz; Filip, Jan, E-mail: claudia.aparicio@upol.cz; Mashlan, Miroslav, E-mail: claudia.aparicio@upol.cz; Zboril, Radek, E-mail: claudia.aparicio@upol.cz [Regional Centre of Advanced Technologies and Materials, Departments of Experimental Physics and Physical Chemistry, Faculty of Science, Palacky University, 17. listopadu 1192/12, 77146 Olomouc (Czech Republic)

    2014-10-27

    Thermally-induced reductive decomposition of natural iron-bearing garnets of the almandine-pyrope and almandine-spessartine series were studied at temperatures up to 1200 C (heating rate of 10 C/min) under atmosphere of forming gas (10% of H{sub 2} in N{sub 2}). Crystallochemical formula of the studied garnet was calculated as {sup VIII}(A{sub 3?x}Fe{sub x}{sup 2+}){sup VI}(Al,Fe{sup 3+}){sub 2}Si{sub 3}O{sub 12}, where the amount of Fe{sup 3+} in the octahedral sites is negligible with the exception of pyrope, A = Mg, Mn, and 0.47 ? x ? 2.85. The observed decomposition temperature, determined from differential scanning calorimetry and thermogravimetry, is greater than 1000 C in all cases and showed almost linear dependence on the iron content in the dodecahedral sites of the studied garnets, with the exception of garnet with a near-pyrope composition (Prp{sub 80}Alm{sub 20}). The initial garnet samples and decomposition products were characterized in details by means of X-ray powder diffraction and {sup 57}Fe Mssbauer spectroscopy. We found that all studied garnets have common decomposition products such as metallic iron (in general, rounded particles below 4 ?m) and Fe-spinel; the other identified decomposition products depend on starting chemical composition of the garnet: Fe-cordierite, olivine (fayalite or tephroite), cristobalite, pyroxene (enstatite or pigeonite), and anorthite. Anorthite and pigeonite were only present in garnets with Ca in the dodecahedral site. All the identified phases were usually well crystallized.

  5. Industry @ ALS

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

    Industry @ ALS Industry @ ALS ALS, Molecular Foundry, and aBeam Technologies Collaborate to Make Metrology History Print Thursday, 21 January 2016 12:47 A collaboration between Bay Area company aBeam Technologies, the ALS, and the Molecular Foundry is bringing cutting-edge metrology instrumentation to the semiconductor market, which will enable a new level of quality control. Summary Slide Read more... Takeda Advances Diabetes Drug Development at the ALS Print Tuesday, 19 May 2015 12:25 Type 2

  6. ALS Spectrum

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

    ALS Spectrum Print Begun in 2007, ALS Spectrum is a publication that encapsulates the same type of information contained in the ALS Activity Report but in a short, readable, newsletter-like format. Featured scientific and facility developments are front-paged, and a roundup of science highlights is provided in easily browsable summaries with Web links. Contents also include brief reports from ALS staff and user groups, articles about ALS people and events, and facility updates. These documents

  7. Unoccupied electronic states of icosahedral Al-Pd-Mn quasicrystals...

    Office of Scientific and Technical Information (OSTI)

    Authors: Maniraj, M. ; Rai, Abhishek ; Barman, S. R. ; Kraj, M. ; Schlagel, D. L. ; Lograsso, T. A. ; Horn, K. Publication Date: 2014-09-05 OSTI Identifier: 1181508 Grant...

  8. 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 Authors: Maniraj, M. ; Rai, Abhishek ; Barman, S. R. ; Krajčí, M. ; Schlagel, D. L. ; Lograsso, T. A. ; Horn, K. Publication Date: 2014-09-05 OSTI Identifier: 1181508 Grant/Contract Number: 2/0111/11 Type: Publisher's Accepted Manuscript Journal Name: Physical Review B Additional Journal Information: Journal Volume: 90; Journal Issue: 11; Journal ID: ISSN 1098-0121 Publisher: American Physical Society

  9. ALS Spectrum

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

    Spectrum Print Begun in 2007, ALS Spectrum is a publication that encapsulates the same type of information contained in the ALS Activity Report but in a short, readable, newsletter-like format. Featured scientific and facility developments are front-paged, and a roundup of science highlights is provided in easily browsable summaries with Web links. Contents also include brief reports from ALS staff and user groups, articles about ALS people and events, and facility updates. These documents are

  10. 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.

  11. ALS Visitors

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

    Quick Facts ALS Visitors Print ALS staff members host a variety of scientific, educational, government, and community-related tours each month. April 2014 Congresswoman Jackie Speier, who represents southern San Francisco and northern Peninsula communities, recently spent an afternoon at Berkeley Lab. In addition to an overview of the Lab provided by Lab Director Paul Alivisatos, Speier toured the FLEXLAB and the Advanced Light Source. At the ALS she spoke with Beamline Scientist Ken Goldberg

  12. ALS Spectrum

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

    encapsulates the same type of information contained in the ALS Activity Report but in a short, readable, newsletter-like format. Featured scientific and facility developments are...

  13. ALS Visitors

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

    February 7. After presentations about climate change research from Margaret Torn, Billy Collins, and others, the group toured the ALS with Director Roger Falcone, and stopped by...

  14. ALS Visitors

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

    7. After presentations about climate change research from Margaret Torn, Billy Collins, and others, the group toured the ALS with Director Roger Falcone, and stopped by...

  15. 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.

  16. 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

  17. 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

  18. 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.

  19. AL. I

    Office of Legacy Management (LM)

    AL. I Department of Energy Washington, DC 20545 OCT 13 Vii87 Mr. John T. Shields A214 National Fertilizer Development Center Tennessee Valley Authority Muscle Shoals, Alabama 35660 Dear Mr. Shields: As you may know, the Department of Energy (DOE) is evaluating the radiological condition of sites that were utilized under the Manhattan Engineer District and the Atomic Energy Commission (AEC) during the early years of nuclear development to determine whether they need remedial action and whether

  20. 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

  1. 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.

  2. 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.

  3. About the ALS

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

    ALS About the ALS Print Quick Facts An overview of how the ALS works, its science, funding, capabilities, and history. Mission Statement "Support users in doing outstanding science in a safe environment." ALS in the News Recent stories, press releases, and images featuring ALS staff, users, and science. You can also view ALS visitors and award recipients. Strategic Plan Roadmap for the renewal of ALS facility and scientific programs. Organization ALS organization chart; associated

  4. 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.

  5. 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.

  6. 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

  7. 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 ...

  8. ALS User Meeting

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

    ALS User Meeting Print web banner ALS User Meeting: October 5-7, 2015 Home Agenda Awards Exhibitors Lodging Posters Registration Transportation Workshops Contact Us User Meeting...

  9. ALS Users' Association Charter

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

    Awards: David A. Shirley Award for Outstanding Scientific Achievement at the ALS Klaus Halbach Award for Innovative Instrumentation at the ALS Tim Renner User Services Award for...

  10. ALS Communications Group

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

    Communications Group Print From left: Ashley White, Lori Tamura, Keri Troutman, and Carina Braun. The ALS Communications staff maintain the ALS Web site; write and edit all print...

  11. 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

  12. 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

  13. 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

  14. 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.

  15. ALS User Meeting

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

    ALS User Meeting October 3-5, 2011 Lawrence Berkeley National Laboratory, California

  16. ALS Chemistry Lab

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

    ALS Chemistry Lab Print ALS Chemistry Labs The ALS Chemistry Labs are located in the User Support Building (15-130) and in Building 6 (6-2233)*. These spaces are dedicated for chemistry work that involves higher quantities, higher toxicity or reactivity, and/or more complex work activity than is allowed on the ALS experiment floor. In addition, the great majority of hazardous chemicals at the ALS are stored in these facilities. Standard chemical safety engineering, administrative and PPE

  17. 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.

  18. Access to the ALS

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

    Access to the ALS Access to the ALS Print User Access The ALS experiment floor (Building 6) is a Controlled Access Area for radiation protection. All ALS users are required to register with the ALS User Services Office and take safety training (see Complete Safety Training ) before they are issued a Berkeley Lab ID badge and granted access to the facility. Note: Users arriving at the ALS outside registration business hours (Monday-Friday 8:00 a.m.-4:00 p.m.) must notify the User Office in

  19. ALS Biosciences Crosscutting Review

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

    ALS Biosciences Crosscutting Review ALS Biosciences Crosscutting Review Print by Steve Kevan and Corie Ralston The ALS organized and recently held a two-day crosscutting review of its bioscience programs. The ALS Scientific Advisory Committee (SAC) sponsors these reviews, which are intended to evaluate the performance of entire research subdisciplines served by the facility and to motivate strategic thinking about capabilities and research directions that are ripe for future development. SAC

  20. ALS Communications Group

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

    ALS Communications Group Print From left: Ashley White, Lori Tamura, Keri Troutman, and Carina Braun. The ALS Communications staff maintain the ALS Web site; write and edit all print and electronic publications for the ALS, including Science Highlights, Science Briefs, brochures, handouts, and the monthly newsletter ALSNews; and create educational and scientific outreach materials. In addition, members of the group organize bi-monthly Science Cafés, create conference and workshop Web sites and

  1. ALS Communications Group

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

    ALS Communications Group Print From left: Ashley White, Lori Tamura, Keri Troutman, and Carina Braun. The ALS Communications staff maintain the ALS Web site; write and edit all print and electronic publications for the ALS, including Science Highlights, Science Briefs, brochures, handouts, and the monthly newsletter ALSNews; and create educational and scientific outreach materials. In addition, members of the group organize bi-monthly Science Cafés, create conference and workshop Web sites and

  2. Access to the ALS

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

    Access to the ALS Print User Access The ALS experiment floor (Building 6) is a Controlled Access Area for radiation protection. All ALS users are required to register with the ALS User Services Office and take safety training (see Complete Safety Training ) before they are issued a Berkeley Lab ID badge and granted access to the facility. Note: Users arriving at the ALS outside registration business hours (Monday-Friday 8:00 a.m.-4:00 p.m.) must notify the User Office in advance and have all

  3. Access to the ALS

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

    Gate Access Access to the ALS Print User Access The ALS experiment floor (Building 6) is a Controlled Access Area for radiation protection. All ALS users are required to register with the ALS User Services Office and take safety training (see Complete Safety Training ) before they are issued a Berkeley Lab ID badge and granted access to the facility. Note: Users arriving at the ALS outside registration business hours (Monday-Friday 8:00 a.m.-4:00 p.m.) must notify the User Office in advance and

  4. ALS in the News

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

    feed-image Digg: ALSBerkeleyLab Facebook Page: 208064938929 Flickr: advancedlightsource Twitter: AdvLightSource YouTube: AdvancedLightSource Home About the ALS ALS in the News ALS in the News ALS in the News Print Thursday, 26 February 2015 13:29 Recent Articles Featuring ALS Staff and Science 2015 February New Video: Berkeley Lab's "Who We Are" Grants Give Particle Accelerator Technologies a Boost Details on Presidential Budget Request for DOE R&D DOE Scientists Team up to

  5. 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)

  6. 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.

  7. ALS Activity Reports

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

    ALS Activity Reports Print These hard-copy annual reports were produced from 1993-2006. They illustrated the depth and breadth of the ALS scientific program with a selection of research results. They also summarized operations and ongoing R&D, highlighted educational outreach efforts and special events, and provided yearly documentation of the beamlines and publications. The Activity Report was replaced in 2007 by ALS Spectrum. The reports for 1996-2006 are available here. Activity Report

  8. ALS Communications Group

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

    Communications Group Print From left: Ashley White, Lori Tamura, Keri Troutman, and Carina Braun. The ALS Communications staff maintain the ALS Web site; write and edit all print and electronic publications for the ALS, including Science Highlights, Science Briefs, brochures, handouts, and the monthly newsletter ALSNews; and create educational and scientific outreach materials. In addition, members of the group organize bi-monthly Science Cafés, create conference and workshop Web sites and

  9. ALS Postdoctoral Fellowship Highlights

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

    Postdoctoral Fellowship Highlights Print Since its inception in 2005, the ALS Postdoctoral Fellowship program has supported young scientists in new and ongoing research projects at the ALS. In many cases, the postdoctoral fellows were also supported by collaborating institutions. These postdoc "highlights" -listed chronologically-feature a description of their projects while at the ALS, resulting publications, and their current positions and research activities. Name Year/Beamline

  10. ALS Users' Association Charter

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

    Users' Executive Committee ALS Users' Association Charter Print The purpose of the Advanced Light Source Users' Association (ALSUA) is to provide an organized framework for the interaction between those who use the Advanced Light Source (ALS) at the Lawrence Berkeley Laboratory (LBL) for their research and the ALS management, as well as to provide a channel for communication with other synchrotron radiation laboratories and, on suitable occasions, with federal agencies. The ALSUA, representing

  11. ALS User Meeting

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

    User Meeting ALS User Meeting web banner ALS User Meeting: October 5-7, 2015 Home Agenda Awards Exhibitors Lodging Posters Registration Transportation Workshops Contact Us User Meeting Archives Users' Executive Committee Meeting Highlights Plenary sessions with keynote speakers Reports from Washington and DOE Director's science and facility updates Invited talks featuring recent science highlights from the ALS Poster session and reception Student poster competition "Poster Slam" for

  12. Materials Data on MnAlCo2 (SG:225) by Materials Project

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

    Kristin Persson

    2015-02-09

    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

  13. Materials Data on Sc(MnAl2)4 (SG:139) by Materials Project

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

    Kristin Persson

    2014-11-02

    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

  14. Materials Data on Y(MnAl2)4 (SG:139) by Materials Project

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

    Kristin Persson

    2014-11-02

    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

  15. Materials Data on MnAlFe2 (SG:225) by Materials Project

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

    Kristin Persson

    2015-03-22

    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

  16. Materials Data on MnAlRh2 (SG:225) by Materials Project

    SciTech Connect (OSTI)

    Kristin Persson

    2015-02-09

    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

  17. Materials Data on MnAlCo2 (SG:225) 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

  18. ALS User Meeting Archives

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

    proposals submitted to funding agencies and for contributions promoting the ALS in general. 1999 Roland Kawakami, Z.-Q. Qiu (both of the University of California, Berkeley), and...

  19. ALS Chemistry Lab

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

    These spaces are dedicated for chemistry work that involves higher quantities, higher toxicity or reactivity, andor more complex work activity than is allowed on the ALS...

  20. ALS Chemistry Lab

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

    the great majority of hazardous chemicals at the ALS are stored in these facilities. Standard chemical safety engineering, administrative and PPE controls are employed in...

  1. Science DMZ for ALS

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

    ALS Science Engagement Move your data Programs & Workshops Science Requirements Reviews Case Studies OSCARS Case Studies Science DMZ Case Studies Science DMZ @ UF Science DMZ @ CU...

  2. ALS in the News

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

    ALS in the News ALS in the News Print Thursday, 26 February 2015 13:29 Recent Articles Featuring ALS Staff and Science 2015 February New Video: Berkeley Lab's "Who We Are" Grants Give Particle Accelerator Technologies a Boost Details on Presidential Budget Request for DOE R&D DOE Scientists Team up to Demonstrate Scientific Potential of Big Data Infrastructure January Timeline Chronicles Lab's Science Highlights in 2014 (...and the ALS is well represented!) New Lithium-Ion Battery

  3. 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.

  4. Anisotropic swelling and microcracking of neutron irradiated Ti3AlC2-Ti5Al2C3 materials

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

    Ang, Caen K.; Silva, Chinthaka M.; Shih, Chunghao Phillip; Koyanagi, Takaaki; Katoh, Yutai; Zinkle, Steven J.

    2015-12-17

    Mn + 1AXn (MAX) phase materials based on Ti–Al–C have been irradiated at 400 °C (673 K) with fission neutrons to a fluence of 2 × 1025 n/m2 (E > 0.1 MeV), corresponding to ~ 2 displacements per atom (dpa). We report preliminary results of microcracking in the Al-containing MAX phase, which contained the phases Ti3AlC2 and Ti5Al2C3. Equibiaxial ring-on-ring tests of irradiated coupons showed that samples retained 10% of pre-irradiated strength. Volumetric swelling of up to 4% was observed. Phase analysis and microscopy suggest that anisotropic lattice parameter swelling caused microcracking. Lastly, variants of titanium aluminum carbide may bemore » unsuitable materials for irradiation at light water reactor-relevant temperatures.« less

  5. 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.

  6. ALS Users' Association Charter

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

    users and will enable users to plan more efficiently the utilization of the facility. The role of the ALSUA shall be to advise the ALS Director on matters of concern to users....

  7. ALS Users' Association Charter

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

    facility. Thorough discussion with users of current projects, as well as plans for the future, will place ALS management in a better position to evaluate the needs of users and...

  8. 2013 ALS User Meeting

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

    3 ALS User Meeting banner Home Agenda Awards Exhibitors Lodging Posters Registration T-Shirt Contest Transportation Workshops Contact Us User Meeting Archives Users' Executive Committee 2013 Meeting Highlights Celebrating 20 Years of Great Science! Plenary sessions with keynote speakers Reports from Washington and DOE Director's science and facility updates Invited talks featuring recent science highlights from the ALS Science communications strategies talk Poster session and reception Student

  9. ALS Activity Reports

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

    Activity Reports Print These hard-copy annual reports were produced from 1993-2006. They illustrated the depth and breadth of the ALS scientific program with a selection of research results. They also summarized operations and ongoing R&D, highlighted educational outreach efforts and special events, and provided yearly documentation of the beamlines and publications. The Activity Report was replaced in 2007 by ALS Spectrum. The reports for 1996-2006 are available here. Activity Report 2006

  10. ALS Activity Reports

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

    Activity Reports Print These hard-copy annual reports were produced from 1993-2006. They illustrated the depth and breadth of the ALS scientific program with a selection of research results. They also summarized operations and ongoing R&D, highlighted educational outreach efforts and special events, and provided yearly documentation of the beamlines and publications. The Activity Report was replaced in 2007 by ALS Spectrum. The reports for 1996-2006 are available here. Activity Report 2006

  11. ALS Beamlines Directory

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

    ALS Beamlines Directory Print Beamlines, Parameters, Contact Information, and Schedules Click on the image to download a high-resolution version of the ALS beamclock. Beamline Parameters Beamline and endstation technical information is available through the links below. Unless otherwise noted, all beamlines are currently operational. Individual beamline schedules are posted when available. Please contact the responsible beamline scientist for additional schedule information. When calling from

  12. ALS Users' Association Charter

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

    Users' Association Charter Print The purpose of the Advanced Light Source Users' Association (ALSUA) is to provide an organized framework for the interaction between those who use the Advanced Light Source (ALS) at the Lawrence Berkeley Laboratory (LBL) for their research and the ALS management, as well as to provide a channel for communication with other synchrotron radiation laboratories and, on suitable occasions, with federal agencies. The ALSUA, representing the research workers, will be in

  13. ALS Users' Association Charter

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

    Users' Association Charter Print The purpose of the Advanced Light Source Users' Association (ALSUA) is to provide an organized framework for the interaction between those who use the Advanced Light Source (ALS) at the Lawrence Berkeley Laboratory (LBL) for their research and the ALS management, as well as to provide a channel for communication with other synchrotron radiation laboratories and, on suitable occasions, with federal agencies. The ALSUA, representing the research workers, will be in

  14. 2013 ALS User Meeting

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

    2013 ALS User Meeting Print banner Home Agenda Awards Exhibitors Lodging Posters Registration T-Shirt Contest Transportation Workshops Contact Us User Meeting Archives Users' Executive Committee 2013 Meeting Highlights Celebrating 20 Years of Great Science! Plenary sessions with keynote speakers Reports from Washington and DOE Director's science and facility updates Invited talks featuring recent science highlights from the ALS Science communications strategies talk Poster session and reception

  15. ALS Activity Reports

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

    Activity Reports Print These hard-copy annual reports were produced from 1993-2006. They illustrated the depth and breadth of the ALS scientific program with a selection of research results. They also summarized operations and ongoing R&D, highlighted educational outreach efforts and special events, and provided yearly documentation of the beamlines and publications. The Activity Report was replaced in 2007 by ALS Spectrum. The reports for 1996-2006 are available here. Activity Report 2006

  16. ALS Beamlines Directory

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

    ALS Beamlines Directory Print Beamlines, Parameters, Contact Information, and Schedules Click on the image to download a high-resolution version of the ALS beamclock. Beamline Parameters Beamline and endstation technical information is available through the links below. Unless otherwise noted, all beamlines are currently operational. Individual beamline schedules are posted when available. Please contact the responsible beamline scientist for additional schedule information. When calling from

  17. ALS Beamlines Directory

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

    Beamlines Directory ALS Beamlines Directory Print Beamlines, Parameters, Contact Information, and Schedules Click on the image to download a high-resolution version of the ALS beamclock. Beamline Parameters Beamline and endstation technical information is available through the links below. Unless otherwise noted, all beamlines are currently operational. Individual beamline schedules are posted when available. Please contact the responsible beamline scientist for additional schedule information.

  18. ALS Beamlines Directory

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

    ALS Beamlines Directory Print Beamlines, Parameters, Contact Information, and Schedules Click on the image to download a high-resolution version of the ALS beamclock. Beamline Parameters Beamline and endstation technical information is available through the links below. Unless otherwise noted, all beamlines are currently operational. Individual beamline schedules are posted when available. Please contact the responsible beamline scientist for additional schedule information. When calling from

  19. 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

  20. Ferromagnetic response of multiferroic TbMnO{sub 3} films mediated by epitaxial strain and chemical pressure

    SciTech Connect (OSTI)

    Izquierdo, J.; Morn, O.; Astudillo, A.; Bolaos, G.; Arnache, O.

    2014-05-07

    High quality Tb{sub 1?x}Al{sub x}MnO{sub 3} (x?=?0, 0.3) films have been grown under different values of compressive/tensile strain using (001)-oriented SrTiO{sub 3} and MgO substrates. The films were grown by means of rf sputtering at substrate temperature of 800??C. X-ray diffraction analysis shows that films are single phase, preferentially oriented in the (111) and (122) directions for films deposited on SrTiO{sub 3} and MgO substrates, respectively. Although the TbMnO{sub 3} target shows antiferromagnetic order, the films deposited on both substrates show weak ferromagnetic phase at low temperature coexisting with the antiferromagnetic phase. The introduction of Al in the films clearly enhances their ferromagnetic behavior, improving the magnetic performance of this material. Indeed, M(H) measurements at 5?K show a well-defined hysteresis for films grown on both substrates. However, a stronger magnetic signal (larger values of remanence and coercive field) is observed for films deposited on MgO substrates. The chemical pressure generated by Al doping together with the substrate-induced strain seem to modify the subtle competition between magnetic interactions in the system. It is speculated that such modification could lead to a non-collinear magnetic state that may be tuned by strain modifications. This may be performed by varying the thickness of the films and/or considering other substrate materials.

  1. 2012 ALS User Meeting Awards

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

    2012 ALS User Meeting Awards Print Recipients of the 2012 Users' Executive Committee awards and Student Poster Competition were announced Tuesday, October 9, at the ALS User...

  2. 2012 ALS User Meeting Awards

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

    2 ALS User Meeting Awards Recipients of the 2012 Users' Executive Committee awards and Student Poster Competition were announced Tuesday, October 9, at the ALS User Meeting. David...

  3. AL PRO | Open Energy Information

    Open Energy Info (EERE)

    search Name: AL-PRO Place: Grossheide, Lower Saxony, Germany Zip: 26532 Sector: Wind energy Product: AL-PRO is an inndependent expert office for wind forecasts, wind...

  4. AL2007-08.doc

    Broader source: Energy.gov (indexed) [DOE]

    Assessment Tool, IEEE Standard 1680-2006 for Environmental Assessment of Personal Computer Products. When is this Acquisition Letter (AL) Effective? This AL is effective...

  5. Magnetic properties of transition metal doped AlN nanosheet: First-principle studies

    SciTech Connect (OSTI)

    Shi, Changmin; Qin, Hongwei Zhang, Yongjia; Hu, Jifan; Ju, Lin

    2014-02-07

    We carry out our first-principles calculations within density functional theory to study the 3d transition metal (TM) doped AlN nanosheets. The calculated results indicate that a stoichiometric AlN nanosheet is graphene-like structure and nonmagnetic. The TM impurities can induce magnetic moments, localized mainly on the 3d TM atoms and neighboring N atoms. Our calculated results of TM-doped nanosheet systems indicate a strong interaction between 3d orbit of TM atom and the 2p orbit of N atoms. In addition, the Mn- and Ni-doped AlN nanosheet with half-metal characters seems to be good candidates for spintronic applications. When substituting two Al atoms, the relative energies of the states between ferromagnetic and antiferromagnetic coupling are investigated sufficiently. The exchange coupling of Co- and Ni-doped AlN nanosheets exhibits a transformation with different distances of two TM atoms and that of Cr-, Mn-, and Fe-doped AlN nanosheets is not changed.

  6. ALS Staff Photo

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

    Staff Photo Print On May 14, 2013, members of ALS staff posed for a group photo in front of the dome. A hi-res version can be downloaded here. The last staff photo was taken in 2006. 2013 staff photo

  7. ALS Staff Photo

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

    Staff Photo Print On May 14, 2013, members of ALS staff posed for a group photo in front of the dome. A hi-res version can be downloaded here. The last staff photo was taken in 2006. 2013 staff photo

  8. 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.

  9. 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

  10. ALS User Meeting Archives

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

    ALS User Meeting Archives Past User Meeting Agendas, Workshops, and Awards Year David A. Shirley (Science) Klaus Halbach (Instrumentation) Tim Renner (Service) 2014 Agenda Workshops Chuck Fadley, "For significant contributions to a better understanding of surfaces and interfaces through the development of novel x-ray photoemission spectroscopy techniques." More... Alastair MacDowell, James Nasiatka, Dula Parkinson, Abdel Haboub, Hrishikesh Bale, and Rob Ritchie, "For the

  11. 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

  12. 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,

  13. 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.

  14. 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 ...

  15. 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 ...

  16. 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...

  17. 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 ...

  18. 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.

  19. 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.

  20. 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}.

  1. 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.

  2. Optimization of chemical compositions in low-carbon Al-killed enamel steel produced by ultra-fast continuous annealing

    SciTech Connect (OSTI)

    Dong, Futao; Du, Linxiu; Liu, Xianghua; Xue, Fei

    2013-10-15

    The influence of Mn,S and B contents on microstructural characteristics, mechanical properties and hydrogen trapping ability of low-carbon Al-killed enamel steel was investigated. The materials were produced and processed in a laboratory and the ultra-fast continuous annealing processing was performed using a continuous annealing simulator. It was found that increasing Mn,S contents in steel can improve its hydrogen trapping ability which is attributed by refined ferrite grains, more dispersed cementite and added MnS inclusions. Nevertheless, it deteriorates mechanical properties of steel sheet. Addition of trace boron results in both good mechanical properties and significantly improved hydrogen trapping ability. The boron combined with nitrogen segregating at grain boundaries, cementite and MnS inclusions, provides higher amount of attractive hydrogen trapping sites and raises the activation energy for hydrogen desorption from them. - Highlights: We study microstructures and properties in low-carbon Al-killed enamel steel. Hydrogen diffusion coefficients are measured to reflect fish-scale resistance. Manganese improves hydrogen trapping ability but decrease deep-drawing ability. Boron improves both hydrogen trapping ability and deep-drawing ability. Both excellent mechanical properties and fish-scale resistance can be matched.

  3. 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.

  4. 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.

  5. (Ca,Na)(Zn,Mn){sub 2}As{sub 2}: A new spin and charge doping decoupled diluted ferromagnetic semiconductor

    SciTech Connect (OSTI)

    Zhao, K.; Chen, B. J.; Deng, Z.; Zhao, G. Q.; Zhu, J. L.; Liu, Q. Q.; Wang, X. C.; Han, W.; Frandsen, B.; Liu, L.; Cheung, S.; Uemura, Y. J.; Ning, F. L.; Munsie, T. J. S.; Medina, T.; Luke, G. M.; Carlo, J. P.; Munevar, J.; Zhang, G. M.; Jin, C. Q.

    2014-10-28

    Here, we report the successful synthesis of a spin- and charge-decoupled diluted magnetic semiconductor (DMS) (Ca,Na)(Zn,Mn){sub 2}As{sub 2}, crystallizing into the hexagonal CaAl{sub 2}Si{sub 2} structure. The compound shows a ferromagnetic transition with a Curie temperature up to 33?K with 10% Na doping, which gives rise to carrier density of n{sub p}???10{sup 20?}cm{sup ?3}. The new DMS is a soft magnetic material with H{sub C}?Mn doping, ferromagnetic order is accompanied by an interaction between the local spin and mobile charge, giving rise to a minimum in resistivity at low temperatures and localizing the conduction electrons. The system provides an ideal platform for studying the interaction of the local spins and conduction electrons.

  6. 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.

  7. ALS Scientific Advisory Committee Charter

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

    Scientific Advisory Committee Charter Print This document was revised and approved December 18, 2008. I. FUNCTION AND REPORTING The ALS Scientific Advisory Committee (SAC) is advisory to the Berkeley Lab Director through the ALS Director. The SAC serves two primary functions: It acts as a "board of directors" to advise the Laboratory on current and future ALS operations, allocation of facility resources, strategic planning, budget development, and other major issues; and It reviews

  8. ALS Scientific Advisory Committee Charter

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

    Scientific Advisory Committee Charter Print This document was revised and approved December 18, 2008. I. FUNCTION AND REPORTING The ALS Scientific Advisory Committee (SAC) is advisory to the Berkeley Lab Director through the ALS Director. The SAC serves two primary functions: It acts as a "board of directors" to advise the Laboratory on current and future ALS operations, allocation of facility resources, strategic planning, budget development, and other major issues; and It reviews

  9. AL2007-05.doc

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

    AL 2007-05 Acquisition Regulation Date 03/29/2007 ACQUISITION LETTER This Acquisition Letter is issued under the authority of the DOE and NNSA Procurement Executives. Acquisition Letters (AL) that remain in effect are identified below. All other previously issued ALs have been superseded by a formal rule-making, incorporated into other guidance, and/or canceled. * * * * * * * * * * * * * * * * ACQUISITION LETTERS REMAINING IN EFFECT NUMBER DATE SUBJECT 93-4 04/07/93 Displaced Workers Benefits

  10. 2012 ALS User Meeting Awards

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

    2 ALS User Meeting Awards Recipients of the 2012 Users' Executive Committee awards and Student Poster Competition were announced Tuesday, October 9, at the ALS User Meeting. David A. Shirley Award for Outstanding Scientific Achievement at the ALS shirley award The David A. Shirley Award for Scientific Achievement went to, from left, Carl Percival (University of Manchester), Dudley Shallcross [(University of Bristol) not pictured], and Craig Taatjes and David Osborn (Sandia), for making the first

  11. 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.

  12. ALS Evidence Confirms Combustion Theory

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

    ALS Evidence Confirms Combustion Theory Print Researchers recently uncovered the first step in the process that transforms gas-phase molecules into solid particles like soot and...

  13. ALS Scientific Advisory Committee Charter

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

    the Laboratory on current and future ALS operations, allocation of facility resources, strategic planning, budget development, and other major issues; and It reviews major...

  14. ALS Collaborative Postdoctoral Fellowship Program

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

    scientists) to discuss possible projects and to identify external sources of matching funds. Applicants must then submit a completed ALS Collaborative Postdoctoral...

  15. Data Management at the ALS

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

    Data Management at the ALS Print Users of the ALS are responsible for meeting their data management obligations to their home institutions and granting agencies. Except as noted below for data stored at NERSC, the ALS does not provide specific resources to manage data that are generated through user experiments. Because the ALS does not have a facility-wide data archiving service or staff to manage the data, the user must generally make arrangements to copy data to their own storage systems or

  16. ALS Scientific Advisory Committee Charter

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

    It acts as a "board of directors" to advise the Laboratory on current and future ALS operations, allocation of facility resources, strategic planning, budget development, and...

  17. ALS Collaborative Postdoctoral Fellowship Program

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

    who will collaborate closely with ALS staff and users in new and emerging scientific and engineering research fields. The program will provide advanced training for careers paths...

  18. 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.

  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. Environmental effect on room-temperature ductility of isothermally forged TiAl-base alloys

    SciTech Connect (OSTI)

    Nakamura, Morihiko; Hashimoto, Kenki (National Research Inst. for Metals, Tokyo (Japan)); Itoh, Naoyuki (Nippon Steel Corp., Chiba (Japan)); Tsujimoto, Tokuzo (Ibaraki Univ. (Japan). Faculty of Engineering); Suzuki, Toshiyuki (Kougakuin Univ., Tokyo (Japan))

    1994-02-01

    Isothermally forged TiAl-base alloy (Al-rich, Mn-containing, and Cr-containing TiAl) were heat-treated in various conditions, and equiaxed grain structures consisting of [gamma] and [alpha][sub 2] or [beta] phases were obtained. The heat-treated alloys were tensile tested in vacuum and air at room temperature, and the environmental effect on tensile elongation was studied. The ductility of the alloys consisting of equiaxed [gamma] grains and a large amount of [alpha][sub 2] grains was not largely affecting by laboratory air, and a decrease in the amount of [alpha][sub 2] grains resulted in a large reduction of ductility in air. The [beta] phase in the Cr-containing alloy improved the ductility in vacuum, but it resulted in a large reduction of ductility in air.

  1. 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.

  2. ALS Collaborative Postdoctoral Fellowship Program

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

    Collaborative Postdoctoral Fellowship Program Print The Advanced Light Source (ALS) Collaborative Postdoctoral Fellowship program provides challenging opportunities to conduct research and instrument development in areas supporting the scientific programs of the Department of Energy (DOE), Lawrence Berkeley National Laboratory (LBNL), and the ALS that include physical, chemical, material, energy, environmental, geological, and biological sciences. Fellows pursue individual research projects as

  3. ALS Collaborative Postdoctoral Fellowship Program

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

    Collaborative Postdoctoral Fellowship Program Print The Advanced Light Source (ALS) Collaborative Postdoctoral Fellowship program provides challenging opportunities to conduct research and instrument development in areas supporting the scientific programs of the Department of Energy (DOE), Lawrence Berkeley National Laboratory (LBNL), and the ALS that include physical, chemical, material, energy, environmental, geological, and biological sciences. Fellows pursue individual research projects as

  4. Effects of (Al,Ge) double doping on the thermoelectric properties of higher manganese silicides

    SciTech Connect (OSTI)

    Chen, Xi; Salta, Daniel; Zhang, Libin [Materials Science and Engineering Program, Texas Materials Institute, The University of Texas at Austin, Austin, Texas 78712 (United States); Weathers, Annie [Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712 (United States); Zhou, Jianshi; Goodenough, John B.; Shi, Li [Materials Science and Engineering Program, Texas Materials Institute, The University of Texas at Austin, Austin, Texas 78712 (United States); Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712 (United States)

    2013-11-07

    Experiments and analysis have been carried out to investigate the effects of Al and (Al,Ge) doping on the microstructure and thermoelectric properties of polycrystalline higher manganese silicide (HMS) samples, which were prepared by solid-state reaction, ball milling, and followed by spark plasma sintering. It has been found that Al doping effectively increases the hole concentration, which leads to an increase in the electrical conductivity and power factor. By introducing the second dopant Ge into Al-doped HMS, the electrical conductivity is increased, and the Seebeck coefficient is decreased as a result of further increased hole concentration. The peak power factor is found to occur at a hole concentration between 1.8??10{sup 21} and 2.2??10{sup 21}?cm{sup ?3} measured at room temperature. The (Al,Ge)-doped HMS samples show lower power factors owing to their higher hole concentrations. The mobility of Mn(Al{sub 0.0035}Ge{sub y}Si{sub 0.9965-y}){sub 1.8} with y?=?0.035 varies approximately as T{sup ?3/2} above 200?K, suggesting acoustic phonon scattering is the dominant scattering mechanism. The thermal conductivity of HMS does not change appreciably by Al or (Al,Ge) doping. The maximum ZT of (Al,Ge)-doped HMS is 0.57 at 823?K, which is similar to the highest value found in the Al-doped HMS samples. The ZT values were reduced in the Mn(Al{sub 0.0035}Ge{sub y}Si{sub 0.9965-y}){sub 1.8} samples with high Ge concentration of y?=?0.025 and 0.035, because of reduced power factor. In addition, a two-band model was employed to show that the hole contribution to the thermal conductivity dominates the bipolar and electron contributions for all samples from 300 to 823?K and accounts for about 12% of the total thermal conductivity at about 800?K.

  5. 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,

  6. 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

  7. 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).

  8. 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

  9. 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.

  10. 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 ...

  11. 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

  12. 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}.

  13. 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.

  14. 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.

  15. ALS Doctoral Fellowship in Residence

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

    and technological research. As the world's first third-generation synchrotron radiation source, the ALS offers outstanding performance in the VUV-soft x-ray energy range and...

  16. ALS 20th Anniversary Celebration

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

    The 20th anniversary of the ALS was celebrated on Friday, October 4, with style, good humor, lots of stories, and a very large cake. More important, however, was the large number...

  17. Scott Taylor, ALS Safety Manager

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

    for safety inspections. There weren't division safety coordinators back in those days, Taylor explains. Joining the ALS reminds Taylor of his early days at the Lab, when he felt...

  18. ALS Doctoral Fellowship in Residence

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

    Doctoral Fellowship in Residence Print The Advanced Light Source (ALS), a division of Lawrence Berkeley National Laboratory, is a national user facility that generates intense x-ray radiation for scientific and technological research. As the world's first third-generation synchrotron radiation source, the ALS offers outstanding performance in the VUV-soft x-ray energy range and excellent performance into the hard x-ray region. The facility welcomes researchers from universities, industries, and

  19. ALS Doctoral Fellowship in Residence

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

    Doctoral Fellowship in Residence Print The Advanced Light Source (ALS), a division of Lawrence Berkeley National Laboratory, is a national user facility that generates intense x-ray radiation for scientific and technological research. As the world's first third-generation synchrotron radiation source, the ALS offers outstanding performance in the VUV-soft x-ray energy range and excellent performance into the hard x-ray region. The facility welcomes researchers from universities, industries, and

  20. ALS Doctoral Fellowship in Residence

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

    Doctoral Fellowship in Residence Print The Advanced Light Source (ALS), a division of Lawrence Berkeley National Laboratory, is a national user facility that generates intense x-ray radiation for scientific and technological research. As the world's first third-generation synchrotron radiation source, the ALS offers outstanding performance in the VUV-soft x-ray energy range and excellent performance into the hard x-ray region. The facility welcomes researchers from universities, industries, and

  1. ALS Evidence Confirms Combustion Theory

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

    ALS Evidence Confirms Combustion Theory ALS Evidence Confirms Combustion Theory Print Wednesday, 22 October 2014 11:43 Researchers recently uncovered the first step in the process that transforms gas-phase molecules into solid particles like soot and other carbon-based compounds. It's a discovery that could help combustion chemists make more efficient, less polluting fuels and help materials scientists fine-tune their carbon nanotubes and graphene sheets for faster, smaller electronics. In

  2. ALS Doctoral Fellowship in Residence

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

    Doctoral Fellowship in Residence Print The Advanced Light Source (ALS), a division of Lawrence Berkeley National Laboratory, is a national user facility that generates intense x-ray radiation for scientific and technological research. As the world's first third-generation synchrotron radiation source, the ALS offers outstanding performance in the VUV-soft x-ray energy range and excellent performance into the hard x-ray region. The facility welcomes researchers from universities, industries, and

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. ALS 20th Anniversary Celebration

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

    20th Anniversary Celebration Print The 20th anniversary of the ALS was celebrated on Friday, October 4, with style, good humor, lots of stories, and a very large cake. More important, however, was the large number of current and former colleagues and users, who were delighted to have the opportunity to visit and catch up with former workmates. When not chatting with colleagues or listening to the high-shool chamber trio, attendees were entertained by a video montage, old photos featuring ALS

  11. Microsoft Word - AL2006-11.doc

    Broader source: Energy.gov (indexed) [DOE]

    Guide Chapter 7.1, Acquisition Planning Acquisition Guide Chapter 42.5, Contract Management Planning When is this Acquisition Letter (AL) Effective? This AL is effective...

  12. ALS Ceramics Materials Research Advances Engine Performance

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

    ALS Ceramics Materials Research Advances Engine Performance ALS Ceramics Materials Research Advances Engine Performance Print Thursday, 27 September 2012 00:00 ritchie ceramics...

  13. ALS@20 Kick-Off Celebration

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

    tribulations encountered during the construction of the ALS from former Director Jay Marx, current ALS Scientific Director Steve Kevan and Director Roger Falcone talked about...

  14. 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.

  15. 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.

  16. A=17Al (1993TI07)

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

    Al (1993TI07) (Not observed) See (1983ANZQ, 1988WA18, 1992AV03).

  17. A=20Al (72AJ02)

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

    72AJ02) (Not illustrated) 20Al has not been observed: see (KE66C

  18. 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.

  19. 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.

  20. 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:

  1. 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

  2. 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.

  3. 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.

  4. Microsoft Word - AL2008-05.doc

    Office of Environmental Management (EM)

    Department of Energy No. AL 2008-05 Acquisition Regulation Date 04/03/2008 ACQUISITION LETTER This Acquisition Letter is issued under the authority of the DOE and NNSA Procurement Executives. Subject: Environmental, Energy, and Transportation Management References: Executive Order 13423, dated January 24, 2007 Implementing Instructions, dated March 28, 2007 When is this Acquisition Letter (AL) effective? This AL is effective upon issuance. When does this AL Expire? This AL remains in effect

  5. ALS Evidence Confirms Combustion Theory

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

    ALS Evidence Confirms Combustion Theory Print Researchers recently uncovered the first step in the process that transforms gas-phase molecules into solid particles like soot and other carbon-based compounds. It's a discovery that could help combustion chemists make more efficient, less polluting fuels and help materials scientists fine-tune their carbon nanotubes and graphene sheets for faster, smaller electronics. In addition, the results could have implications for the burgeoning field of

  6. ALS Evidence Confirms Combustion Theory

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

    ALS Evidence Confirms Combustion Theory Print Researchers recently uncovered the first step in the process that transforms gas-phase molecules into solid particles like soot and other carbon-based compounds. It's a discovery that could help combustion chemists make more efficient, less polluting fuels and help materials scientists fine-tune their carbon nanotubes and graphene sheets for faster, smaller electronics. In addition, the results could have implications for the burgeoning field of

  7. ALS Evidence Confirms Combustion Theory

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

    ALS Evidence Confirms Combustion Theory Print Researchers recently uncovered the first step in the process that transforms gas-phase molecules into solid particles like soot and other carbon-based compounds. It's a discovery that could help combustion chemists make more efficient, less polluting fuels and help materials scientists fine-tune their carbon nanotubes and graphene sheets for faster, smaller electronics. In addition, the results could have implications for the burgeoning field of

  8. ALS Evidence Confirms Combustion Theory

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

    ALS Evidence Confirms Combustion Theory Print Researchers recently uncovered the first step in the process that transforms gas-phase molecules into solid particles like soot and other carbon-based compounds. It's a discovery that could help combustion chemists make more efficient, less polluting fuels and help materials scientists fine-tune their carbon nanotubes and graphene sheets for faster, smaller electronics. In addition, the results could have implications for the burgeoning field of

  9. 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.

  10. 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}

  11. 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...

  12. 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...

  13. 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.

  14. 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 ...

  15. 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...

  16. 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 ...

  17. Synthesis of AlN/Al Polycrystals along with Al Nanoparticles Using Thermal Plasma Route

    SciTech Connect (OSTI)

    Kanhe, Nilesh S.; Nawale, A. B.; Kulkarni, N. V.; Bhoraskar, S. V.; Mathe, V. L.; Das, A. K.

    2011-07-15

    This paper for the first time reports the (200) oriented growth of hexagonal Aluminum nitride crystals during synthesis of aluminum nanoparticles in dc transferred arc thermal plasma reactor by gas phase condensation in nitrogen plasma. The structural and morphological study of as synthesized AlN crystal and aluminium nanoparticles was done by using the x-ray diffraction method, scanning electron microscopy and transmission electron microscopy.

  18. Letter Report Documenting Progress of Second Generation ATF FeCrAl Alloy Fabrication

    SciTech Connect (OSTI)

    Yamamoto,, Y.; Yang, Y.; Field, K. G.; Terrani, K.; Pint, B. A.; Snead, L. L.

    2014-06-10

    Development of the 2nd generation ATF FeCrAl alloy has been initiated, and a candidate alloy was selected for trial tube fabrication through hot-extrusion and gun-drilling processes. Four alloys based on Fe-13Cr-4.5Al-0.15Y in weight percent were newly cast with minor alloying additions of Mo, Si, Nb, and C to promote solid-solution and second-phase precipitate strengthening. The alloy compositions were selected with guidance from computational thermodynamic tools. The lab-scale heats of ~ 600g were arc-melted and drop-cast, homogenized, hot-forged and -rolled, and then annealed producing plate shape samples. An alloy with Mo and Nb additions (C35MN) processed at 800C exhibits very fine sub-grain structure with the sub-grain size of 1-3?m which exhibited more than 25% better yield and tensile strengths together with decent ductility compared to the other FeCrAl alloys at room temperature. It was found that the Nb addition was key to improving thermal stability of the fine sub-grain structure. Optimally, grains of less than 30 microns are desired, with grains up to and order of magnitude in desired produced through Nb addition. Scale-up effort of the C35MN alloy was made in collaboration with a commercial cast company who has a capability of vacuum induction melting. A 39lb columnar ingot with ~81mm diameter and ~305mm height (with hot-top) was commercially cast, homogenized, hot-extruded, and annealed providing 10mm-diameter bar-shape samples with the fine sub-grain structure. This commercial heat proved consistent with materials produced at ORNL at the lab-scale. Tubes and end caps were machined from the bar sample and provided to another work package for the ATF-1 irradiation campaign in the milestone M3FT-14OR0202251.

  19. 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

  20. 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

  1. 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

  2. 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

  3. 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}.

  4. 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.

  5. ALS Operating Schedule on Google Calendar

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

    ALS Operating Schedule on Google Calendar Print ALS Operating Schedule Your browser does not appear to support JavaScript, but this page needs to use JavaScript to display...

  6. Category:Montgomery, AL | Open Energy Information

    Open Energy Info (EERE)

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

  7. Al Corn Clean Fuel | Open Energy Information

    Open Energy Info (EERE)

    Corn Clean Fuel Jump to: navigation, search Name: Al-Corn Clean Fuel Place: Claremont, North Dakota Product: Al-Corn is an ethanol plant located in Claremont, North Dakota, which...

  8. AL2002-05.pdf | Department of Energy

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

    5.pdf AL2002-05.pdf PDF icon AL2002-05

  9. AL2002-06.pdf | Department of Energy

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

    6.pdf AL2002-06.pdf PDF icon AL2002-06

  10. AL2002-07.pdf | Department of Energy

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

    7.pdf AL2002-07.pdf PDF icon AL2002-07

  11. AL2002-08.pdf | Department of Energy

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

    8.pdf AL2002-08.pdf PDF icon AL2002-08

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

  13. Aluminium distribution in ZSM-5 revisited: The role of Al-Al interactions

    SciTech Connect (OSTI)

    Ruiz-Salvador, A. Rabdel; Grau-Crespo, Ricardo; Gray, Aileen E.; Lewis, Dewi W.

    2013-02-15

    We present a theoretical study of the distribution of Al atoms in zeolite ZSM-5 with Si/Al=47, where we focus on the role of Al-Al interactions rather than on the energetics of Al/Si substitutions at individual sites. Using interatomic potential methods, we evaluate the energies of the full set of symmetrically independent configurations of Al siting in a Si{sub 94}Al{sub 2}O{sub 192} cell. The equilibrium Al distribution is determined by the interplay of two factors: the energetics of the Al/Si substitution at an individual site, which tends to populate particular T sites (e.g., the T14 site), and the Al-Al interaction, which at this Si/Al maximises Al-Al distances in general agreement with Dempsey's rule. However, it is found that the interaction energy changes approximately as the inverse of the square of the distance between the two Al atoms, rather than the inverse of the distance expected if this were merely charge repulsion. Moreover, we find that the anisotropic nature of the framework density plays an important role in determining the magnitude of the interactions, which are not simply dependent on Al-Al distances. - Graphical abstract: Role of Al-Al interactions in high silica ZSM-5 is shown to be anisotropic in nature and not dependent solely on Coulombic interactions. Highlights: Black-Right-Pointing-Pointer Si-Al distribution in ZSM-5 is revisited, stressing the role of the Al-Al interaction. Black-Right-Pointing-Pointer Coulomb interactions are not the key factors controlling the Al siting. Black-Right-Pointing-Pointer Anisotropy of the framework is identified as a source of departure from Dempsey's rule.

  14. AL2002-04.pdf | Department of Energy

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

    4.pdf AL2002-04.pdf PDF icon AL2002-04.pdf More Documents & Publications AL2004-01r2.pdf AL2002-01.pdf AL2002-08...

  15. AL2002-01.pdf | Department of Energy

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

    2-01.pdf AL2002-01.pdf PDF icon AL2002-01.pdf More Documents & Publications AL2002-04.pdf AL2002-08.pdf AL2002-06

  16. 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.

  17. 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.

  18. Stability and Rate Capability of Al Substituted Lithium-Rich High-Manganese Content Oxide Materials for Li-Ion Batteries

    SciTech Connect (OSTI)

    Li, Zheng; Chernova, Natasha A.; Feng, Jijun; Upreti, Shailesh; Omenya, Fredrick; Whittingham, M. Stanley

    2015-10-15

    The structures, electrochemical properties and thermal stability of Al-substituted lithium-excess oxides, Li{sub 1.2}Ni{sub 0.16} Mn{sub 0.56}Co{sub 0.08-y}Al{sub y}O{sub 2} (y = 0, 0.024, 0.048, 0.08), are reported, and compared to the stoichiometric compounds, LiNi{sub z}Mn{sub z}Co{sub 1-2z}O{sub 2}. A solid solution was found up to at least y = 0.06. Aluminum substitution improves the poor thermal stability while preserving the high energy density of lithium-excess oxides. However, these high manganese compositions are inferior to the lithium stoichiometric materials, LiNi{sub z}Mn{sub z}Co{sub 1-2z}O{sub 2} (z = 0.333, 0.4), in terms of both power and thermal stability.

  19. Measurement of the transmission magnetic circular dichroism of Ga{sub 1?x}Mn{sub x}As epilayers using a built-in p-i-n photodiode

    SciTech Connect (OSTI)

    He, Z. X.; Zheng, H. Z. Wang, H. L.; Zhao, J. H.

    2014-02-28

    By constructing a GaMnAs epilayer/semi-insulating In{sub 0.2}Ga{sub 0.8}As/(001) n{sup +}-GaAs substrate layer structure as a built-in p-i-n photodiode, we developed a scheme for on-chip measurements of transmission magnetic circular dichroism (T-MCD). Both the hysteresis loops in the magnetic field sweeps and the wavelength scans at saturated magnetic fields measured using the new T-MCD scheme, illustrated the same features as those previously measured on the freestanding GaMnAs thin films by conventional T-MCD. Because a large group of epitaxially grown magnetic film/semiconductor heterostructures, such as Fe, NiFe, CoFeAl, and MnGa films on semiconductor substrates, are becoming important new building blocks for semiconductor-based spin field-effect transistor, perpendicular magnetic tunnel junction (p-MTJ) and lateral MTJ devices, the new T-MCD scheme can be applied to tests of their magnetic properties by forming either p-i-n or Schottky photodiodes.

  20. 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.

  1. 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.

  2. 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+}.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. ALS Ceramics Materials Research Advances Engine Performance

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

    ALS Ceramics Materials Research Advances Engine Performance ALS Ceramics Materials Research Advances Engine Performance Print Thursday, 27 September 2012 00:00 ritchie ceramics This 3D image of a ceramic composite specimen imaged under load at 1750C shows the detailed fracture patterns that researchers are able to view using ALS Beamline 8.3.2. The vertical white lines are the individual silicon carbide fibers in this sample about 500 microns in diameter. LBNL senior materials scientist and U.C.

  10. IBM Probes Material Capabilities at the ALS

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

    IBM Probes Material Capabilities at the ALS IBM Probes Material Capabilities at the ALS Print Wednesday, 12 February 2014 11:05 Vanadium dioxide, one of the few known materials that acts like an insulator at low temperatures but like a metal at warmer temperatures, is a somewhat futuristic material that could yield faster and much more energy-efficient electronic devices. Researchers from IBM's forward-thinking Spintronic Science and Applications Center (SpinAps) recently used the ALS to gain

  11. Footprinting Technique Gives ALS Users New Insights

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

    Footprinting Technique Gives ALS Users New Insights Footprinting Technique Gives ALS Users New Insights Print Thursday, 24 September 2015 09:32 Recent research at ALS Beamline 5.3.1, detailed in this month's Science Highlight, revealed that an important photosynthetic mechanism called "nonphotochemical quenching" is triggered by the translocation of the carotenoid pigment within a critical light-sensitive protein called the Orange Carotenoid Protein (OCP). The x-ray footprinting (XFP)

  12. Crystallographic Consulting Brings Research to the ALS

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

    Crystallographic Consulting Brings Research to the ALS Crystallographic Consulting Brings Research to the ALS Print Wednesday, 06 February 2013 15:50 cc Tom Pauly and Josh Stillwell, managing partners at Crystallographic Consulting, have a rich history as synchrotron users. It is likely because of this that they're entrusted with the protein crystallography research for about 15 cutting-edge pharmaceutical companies. They conduct most of their research at ALS Beamline 5.0.2. Crystallographic

  13. ALS Ceramics Materials Research Advances Engine Performance

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

    ALS Ceramics Materials Research Advances Engine Performance ALS Ceramics Materials Research Advances Engine Performance Print Thursday, 27 September 2012 00:00 ritchie ceramics This 3D image of a ceramic composite specimen imaged under load at 1750C shows the detailed fracture patterns that researchers are able to view using ALS Beamline 8.3.2. The vertical white lines are the individual silicon carbide fibers in this sample about 500 microns in diameter. LBNL senior materials scientist and U.C.

  14. IBM Probes Material Capabilities at the ALS

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

    IBM Probes Material Capabilities at the ALS IBM Probes Material Capabilities at the ALS Print Wednesday, 12 February 2014 11:05 Vanadium dioxide, one of the few known materials that acts like an insulator at low temperatures but like a metal at warmer temperatures, is a somewhat futuristic material that could yield faster and much more energy-efficient electronic devices. Researchers from IBM's forward-thinking Spintronic Science and Applications Center (SpinAps) recently used the ALS to gain

  15. 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.

  16. Crystallographic Consulting Brings Research to the ALS

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

    of the participating research team (PRT) members at the Berkeley Center for Structural Biology (BCSB), which operates five ALS beamlines. As PRT members, companies are...

  17. Al Turi Biomass Facility | Open Energy Information

    Open Energy Info (EERE)

    NEEDS 2006 Database Retrieved from "http:en.openei.orgwindex.php?titleAlTuriBiomassFacility&oldid397128" Feedback Contact needs updating Image needs updating...

  18. April 27, 2015-Special ALS Colloquium

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

    Years Janos Kirz, ALS Abstract Rntgen's great discovery became an instant public sensation. Fascination with the "new kind of rays" that could reveal the structure of opaque...

  19. Al Furat Petroleum Company | Open Energy Information

    Open Energy Info (EERE)

    Furat Petroleum Company Name: Al Furat Petroleum Company Place: Damascus, Syria Product: oil and hydrocarbon gas Year Founded: 1985 Phone Number: 00963-11- (6183333) Website:...

  20. ALS Reveals New State of Matter

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

    ALS Reveals New State of Matter ALS Reveals New State of Matter Print Wednesday, 13 October 2010 00:00 ALS user groups from Princeton and Stanford have been making waves this past year with several high-profile papers and extensive news coverage of their work on a new state of matter embodied by "topological insulators," materials that conduct electricity only on their surfaces. First identified at the ALS in 2007 by a Princeton team led by M. Zahid Hasan, topological insulators have

  1. IBM Probes Material Capabilities at the ALS

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

    Researchers from IBM's forward-thinking Spintronic Science and Applications Center (SpinAps) recently used the ALS to gain greater insight into vanadium dioxide's unusual phase ...

  2. Ringleader: Cobber Lam, ALS Systems Administrator

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

    Cobber Lam, ALS Systems Administrator Print Cobber Lam started working at Berkeley Lab 10 years ago as a student assistant, while attending college at Cal State East Bay. Within two months, he was assigned to the ALS and has stayed put ever since. He used to be matrixed via IT, but last year he became a direct ALS employee. ALS IT support is divided between Lam and Tim Kellogg, with Lam being more forward-facing, dealing with users and staff, and Kellogg working on the back-end mostly with

  3. Microsoft Word - al2006-12.doc

    Broader source: Energy.gov (indexed) [DOE]

    AL-2006-12 (092906) 7 III. What Procedures Ensure Effective Audit Management? Some strategies for managing required audit activity include: 1. Contracting officers should...

  4. Al Tayyar Energy | Open Energy Information

    Open Energy Info (EERE)

    Jump to: navigation, search Name: Al Tayyar Energy Place: Abu Dhabi, United Arab Emirates Sector: Renewable Energy Product: Provides development capital and equity investments...

  5. 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.

  6. 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.

  7. 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

  8. 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

  9. 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.

  10. 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.

  11. 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

  12. 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:

  13. 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:

  14. 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:

  15. 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

  16. 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.

  17. 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+}.

  18. 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

  19. 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

  20. 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.

  1. 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}.

  2. 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

  3. 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.

  4. Microsoft Word - AL2008-05.doc | Department of Energy

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

    Microsoft Word - AL2008-05.doc Microsoft Word - AL2008-05.doc Microsoft Word - AL2008-05.doc More Documents & Publications Microsoft Word - AL 2010-07 Acquistion Letters Remaining...

  5. AL2010-01.pdf | Department of Energy

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

    1.pdf AL2010-01.pdf PDF icon AL2010-01.pdf More Documents & Publications G Microsoft Word - AL-Omnibus FY 2009 Apr 22 2009 all sections.doc Microsoft Word - AL-Consolidated Approps...

  6. AL2007-09.pdf | Department of Energy

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

    7-09.pdf AL2007-09.pdf PDF icon AL2007-09.pdf More Documents & Publications AL2007-04.pdf RL-2007OMCPIA.pdf AL2007-06.pdf...

  7. AL2007-04.pdf | Department of Energy

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

    4.pdf AL2007-04.pdf PDF icon AL2007-04.pdf More Documents & Publications Preliminary Notice of Violation, BWXT Y-12 LLC - EA-2007-04 AL2007-05.doc&0; AL2007-09...

  8. AL2007-06.pdf | Department of Energy

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

    6.pdf AL2007-06.pdf PDF icon AL2007-06.pdf More Documents & Publications AL2007-04.pdf AL2007-09.pdf RL-2007OMCPIA...

  9. Acquisition Letter No. AL 2013-08 | Department of Energy

    Energy Savers [EERE]

    8 Acquisition Letter No. AL 2013-08 PDF icon AL 2013-08.pdf More Documents & Publications Acquisition Letters No. AL 2013-05 Acquisiton Letter No. AL 2016-04 POLICY FLASH 2016-17

  10. Microsoft Word - AL2005-10.doc | Department of Energy

    Office of Environmental Management (EM)

    10.doc Microsoft Word - AL2005-10.doc PDF icon Microsoft Word - AL2005-10.doc More Documents & Publications Microsoft Word - AL2005-16.doc Audit Report: IG-0860 Microsoft Word - AL2006-08

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. 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

  16. 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

  17. 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

  18. Summary Slides of ALS Industry Highlights

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

    Industry Highlights Print No. Slide Beamline Full Web Highlight ALSNews Volume 18 Collaboration Produces World's Best Metrology Tool 6.1.2 01.27.2016 Vol. 369 17 Takeda Advances Diabetes Research at ALS 5.0.2, 5.0.3 06.02.2015 Vol. 364 16 Metrology for Next-Generation Nanopatterning 7.3.3, 11.0.1 01.28.2015 Vol. 360 15 Caribou Biosciences Has Roots at ALS - 09.24.2014 Vol. 357 13 Lithium-Battery Dendrite Growth: A New View 8.3.2 04.30.2014 Vol. 352 12 IBM Probes Material Capabilities at the ALS

  19. ALS Reveals New State of Matter

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

    ALS Reveals New State of Matter Print ALS user groups from Princeton and Stanford have been making waves this past year with several high-profile papers and extensive news coverage of their work on a new state of matter embodied by "topological insulators," materials that conduct electricity only on their surfaces. First identified at the ALS in 2007 by a Princeton team led by M. Zahid Hasan, topological insulators have been the subject of intense interest, based on unusual quantum

  20. ALS Reveals New State of Matter

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

    ALS Reveals New State of Matter Print ALS user groups from Princeton and Stanford have been making waves this past year with several high-profile papers and extensive news coverage of their work on a new state of matter embodied by "topological insulators," materials that conduct electricity only on their surfaces. First identified at the ALS in 2007 by a Princeton team led by M. Zahid Hasan, topological insulators have been the subject of intense interest, based on unusual quantum

  1. ALS Reveals New State of Matter

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

    ALS Reveals New State of Matter Print ALS user groups from Princeton and Stanford have been making waves this past year with several high-profile papers and extensive news coverage of their work on a new state of matter embodied by "topological insulators," materials that conduct electricity only on their surfaces. First identified at the ALS in 2007 by a Princeton team led by M. Zahid Hasan, topological insulators have been the subject of intense interest, based on unusual quantum

  2. April 27, 2015-Special ALS Colloquium

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

    April 27, 2015-Special ALS Colloquium April 27, 2015-Special ALS Colloquium Print Wednesday, 22 April 2015 13:19 Special Event on Monday, April 27 @ 12 noon, USB 15-253 X-Ray Microscopy: The First 120 Years Janos Kirz, ALS Abstract Röntgen's great discovery became an instant public sensation. Fascination with the "new kind of rays" that could reveal the structure of opaque objects swept the world in 1896. Fifty years later it was widely recognized that the short wavelength of the

  3. ALS Reveals New State of Matter

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

    ALS Reveals New State of Matter Print ALS user groups from Princeton and Stanford have been making waves this past year with several high-profile papers and extensive news coverage of their work on a new state of matter embodied by "topological insulators," materials that conduct electricity only on their surfaces. First identified at the ALS in 2007 by a Princeton team led by M. Zahid Hasan, topological insulators have been the subject of intense interest, based on unusual quantum

  4. ALS Reveals New State of Matter

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

    ALS Reveals New State of Matter Print ALS user groups from Princeton and Stanford have been making waves this past year with several high-profile papers and extensive news coverage of their work on a new state of matter embodied by "topological insulators," materials that conduct electricity only on their surfaces. First identified at the ALS in 2007 by a Princeton team led by M. Zahid Hasan, topological insulators have been the subject of intense interest, based on unusual quantum

  5. 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.

  6. 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

  7. 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

  8. ALS Reveals New State of Matter

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

    New State of Matter Print ALS user groups from Princeton and Stanford have been making waves this past year with several high-profile papers and extensive news coverage of...

  9. Footprinting Technique Gives ALS Users New Insights

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

    formation. The ALS XFP experts at Beamline 5.3.1. From left: Research Scientist Sayan Gupta, Beamline 5.3.1 Scientist Rich Celestre, and BCSB Head Corie Ralston. XFP, a powerful...

  10. Al Husseini Amelio JV | Open Energy Information

    Open Energy Info (EERE)

    Solar Product: JV company to develop a 1GW solar plant in Jordan and an integrated 200MW thin-film module factory. References: Al-Husseini & Amelio JV1 This article is a stub....

  11. Western Baldwin County, AL Grid Interconnection Project

    SciTech Connect (OSTI)

    Thomas DeBell

    2011-09-30

    The Objective of this Project was to provide an additional supply of electricity to the affected portions of Baldwin County, AL through the purchase, installation, and operation of certain substation equipment.

  12. Summary Slides of ALS Industry Highlights

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

    Print No. Slide Beamline Full Web Highlight ALSNews Volume 17 Takeda Advances Diabetes Research at ALS 5.0.2, 5.0.3 06.02.2015 Vol. 364 16 Metrology for Next-Generation...

  13. Microsoft Word - AL2005-11.doc

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

    appropriate reviews; and (5) ensure they pay only for what they negotiated. AL 2005-11 (071505) - 2 - Background DEAR 970.3102-3-70 DOE Policy is based on the assumption...

  14. 17th Annual ALS Users' Association Meeting

    SciTech Connect (OSTI)

    Robinson, Art; Tamura, Lori

    2004-11-29

    It's not exactly Russian roulette, but scheduling October events outdoors is not risk-free, even in usually sunny California. An overflow crowd of more than 400 registered users, ALS staff, and vendors enjoyed a full indoor program featuring science highlights and workshops spread over two and a half days from October 18 to October 20. However, a major storm, heralding the onset of the San Francisco Bay Area rainy season, posed a few weather challenges for the events on the ALS patio.

  15. Footprinting Technique Gives ALS Users New Insights

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

    Footprinting Technique Gives ALS Users New Insights Print Recent research at ALS Beamline 5.3.1, detailed in this month's Science Highlight, revealed that an important photosynthetic mechanism called "nonphotochemical quenching" is triggered by the translocation of the carotenoid pigment within a critical light-sensitive protein called the Orange Carotenoid Protein (OCP). The x-ray footprinting (XFP) technique developed at 5.3.1 allowed researchers to confirm that this translocation

  16. 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

  17. 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}.

  18. Microsoft Word - AL2000-01.doc | Department of Energy

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

    AL2000-01.doc Microsoft Word - AL2000-01.doc PDF icon Microsoft Word - AL2000-01.doc More Documents & Publications AL/FAL 99-01 Department of Energy No Microsoft Word - al2005-04.doc

  19. Microsoft Word - al2005-06.doc | Department of Energy

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

    al2005-06.doc Microsoft Word - al2005-06.doc PDF icon Microsoft Word - al2005-06.doc More Documents & Publications Microsoft Word - AL2006-01.doc OPAM Policy Acquisition Guides Acquisition Letter: AL2005-08

  20. Microsoft Word - AL2000-05.doc | Department of Energy

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

    .doc Microsoft Word - AL2000-05.doc PDF icon Microsoft Word - AL2000-05.doc More Documents & Publications al99-06.doc&#0; Microsoft Word - AL2000-05Attachment.doc AL2004-01r2.pdf

  1. Microsoft Word - AL2004-02.doc | Department of Energy

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

    4-02.doc Microsoft Word - AL2004-02.doc PDF icon Microsoft Word - AL2004-02.doc More Documents & Publications Microsoft Word - AL2005-02.doc Microsoft Word - al2005-04.doc Microsoft Word - AL-Omnibus FY 2009 Apr 22 2009 all sections

  2. Microsoft Word - AL2005-02.doc | Department of Energy

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

    5-02.doc Microsoft Word - AL2005-02.doc PDF icon Microsoft Word - AL2005-02.doc More Documents & Publications Microsoft Word - AL-Omnibus FY 2009 Apr 22 2009 all sections.doc Microsoft Word - AL2004-02.doc Microsoft Word - AL-Consolidated Approps FY 2008 as of feb 21 2008 final

  3. Microsoft Word - AL2005-14.doc | Department of Energy

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

    4.doc Microsoft Word - AL2005-14.doc PDF icon Microsoft Word - AL2005-14.doc More Documents & Publications Microsoft Word - AL-Omnibus FY 2009 Apr 22 2009 all sections.doc Microsoft Word - AL-Consolidated Approps FY 2008 as of feb 21 2008 final.doc Microsoft Word - AL2006-08.doc

  4. AL2000-10Attach.pdf | Department of Energy

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

    AL2000-10Attach.pdf AL2000-10Attach.pdf PDF icon AL2000-10Attach.pdf More Documents & Publications AL2000-10R.pdf AL2004-01r2.pdf Consent Order, Fluor Federal Services - EA-2000-10...

  5. Microsoft Word - al2007-11.doc | Department of Energy

    Office of Environmental Management (EM)

    al2007-11.doc Microsoft Word - al2007-11.doc PDF icon Microsoft Word - al2007-11.doc More Documents & Publications Acquisition Letter: AL2005-08 Microsoft Word - al2004-03.doc OPAM Policy Acquisition Guides

  6. Microsoft Word - AL2006-08.doc | Department of Energy

    Office of Environmental Management (EM)

    6-08.doc Microsoft Word - AL2006-08.doc PDF icon Microsoft Word - AL2006-08.doc More Documents & Publications AL2007-05.doc&#0; Microsoft Word - AL2005-14.doc Microsoft Word - AL2006-03

  7. 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 ...

  8. 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

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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)

  18. 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.

  19. 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:

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. G I E Al Wahdoui | Open Energy Information

    Open Energy Info (EERE)

    I E Al Wahdoui Jump to: navigation, search Name: G.I.E. Al Wahdoui Place: Morocco Zip: BP 131 Sector: Solar Product: GIE Al Wahdoui is developing a solar project in Plage, Morocco....

  10. Microsoft Word - AL2006-07.doc | Department of Energy

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

    7.doc Microsoft Word - AL2006-07.doc PDF icon Microsoft Word - AL2006-07.doc More Documents & Publications OPAM Policy Acquisition Guides Personal Property Management Certification Brochure Microsoft Word - AL2005-07

  11. Microsoft Word - al2006-12.doc | Department of Energy

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

    al2006-12.doc Microsoft Word - al2006-12.doc PDF icon Microsoft Word - al2006-12.doc More Documents & Publications Department of Energy Special Report: DOE/IG-0934

  12. Microsoft Word - AL2006-01.doc | Department of Energy

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

    1.doc Microsoft Word - AL2006-01.doc PDF icon Microsoft Word - AL2006-01.doc More Documents & Publications Microsoft Word - al2005-06.doc Chapter 19 - Small Business Programs OPAM Policy Acquisition Guides

  13. Microsoft Word - AL2006-02.doc | Department of Energy

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

    2.doc Microsoft Word - AL2006-02.doc PDF icon Microsoft Word - AL2006-02.doc More Documents & Publications Microsoft Word - AL2006-03.doc Archived Financial Assistance Letters Microsoft Word - FAL2006-04.doc

  14. Microsoft Word - AL2008-06.doc | Department of Energy

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

    AL2008-06.doc Microsoft Word - AL2008-06.doc PDF icon Microsoft Word - AL2008-06.doc More Documents & Publications Chapter 9 - Contracting Qualifications Microsoft Word - PART 970.doc Microsoft Word - Matrixpart2.doc

  15. AL2010-04.pdf | Department of Energy

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

    4.pdf AL2010-04.pdf PDF icon AL2010-04.pdf More Documents & Publications Financial Assistance Letter No. FAL 2010-04 Microsoft Word - Section 311 AL FAL Feb 17 2010 FAR Acquisition...

  16. AL2001-04.pdf | Department of Energy

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

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  17. AL2006-05.pdf | Department of Energy

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

    5.pdf AL2006-05.pdf PDF icon AL2006-05.pdf More Documents & Publications 2006 EMAB Recommendation Summary Microsoft Word - AL2006-08.doc DOEECRReport2006(2).pdf...

  18. Acquisition Letter No. AL 2013-07 | Department of Energy

    Energy Savers [EERE]

    7 Acquisition Letter No. AL 2013-07 PDF icon AL 2013-07.pdf More Documents & Publications Policy Flash 2015-05 - Acquisition Letter 2015-02 Acquisition Letter No. AL 2015-02

  19. Microsoft Word - AL2006-11.doc | Department of Energy

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

    AL2006-11.doc Microsoft Word - AL2006-11.doc PDF icon Microsoft Word - AL2006-11.doc More Documents & Publications Subject: Cost and Price Analysis Subject: Cost and Price Analysis...

  20. al99-06.doc | Department of Energy

    Broader source: Energy.gov (indexed) [DOE]

    .doc&#0; More Documents & Publications Microsoft Word - AL2000-05.doc AL2007-05.doc&#0; AL2004-01r2.pdf

  1. AL2001-01.pdf | Department of Energy

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

    1-01.pdf AL2001-01.pdf PDF icon AL2001-01.pdf More Documents & Publications FAL2001-03.pdf FAL2001-02.pdf AL2001-04

  2. 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.

  3. DOE - Office of Legacy Management -- Alabama Ordnance Works - AL 02

    Office of Legacy Management (LM)

    Alabama Ordnance Works - AL 02 FUSRAP Considered Sites Site: Alabama Ordnance Works (AL.02 ) Eliminated from consideration under FUSRAP - Referred to DoD Designated Name: Not Designated Alternate Name: None Location: Sylacauga , Alabama AL.02-1 Evaluation Year: 1987 AL.02-1 Site Operations: Involved in the production of heavy water for the MED. AL.02-1 Site Disposition: Eliminated - No indication of residual radioactive contamination - Referred to DOD AL.02-1 Radioactive Materials Handled: None

  4. Optimization of exchange bias in Co{sub 2}FeAl{sub 0.5}Si{sub 0.5} Heusler alloy layers

    SciTech Connect (OSTI)

    Hirohata, Atsufumi; Izumida, Keisuke; Ishizawa, Satoshi; Nakayama, Tadachika; Sagar, James

    2014-05-07

    We have fabricated and investigated IrMn{sub 3}/Co{sub 2}FeAl{sub 0.5}Si{sub 0.5} stacks to meet the criteria for future spintronic device applications which requires low-temperature crystallisation (<250 °C) and a large exchange bias H{sub ex} (>500 Oe). Such a system would form the pinned layer in spin-valve or tunnel junction applications. We have demonstrated that annealing at 300 °C which can achieve crystalline ordering in the Co{sub 2}FeAl{sub 0.5}Si{sub 0.5} layer giving ∼80% of the predicted saturation magnetisation. We have also induced an exchange bias of ∼240 Oe at the interface. These values are close to the above criteria and confirm the potential of using antiferromagnet/Heusler-alloy stacks in current Si-based processes.

  5. Promising Magnesium Battery Research at ALS

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

    Promising Magnesium Battery Research at ALS Promising Magnesium Battery Research at ALS Print Wednesday, 23 January 2013 16:59 toyota battery a) Cross-section of the in situ electrochemical/XAS cell with annotations. b) Drawing and c) photograph of the assembled cell. Alternatives to the current lithium-ion-based car batteries are at the forefront of the automotive industry's research agenda-manufacturers want to build cars with longer battery life, and to do that they're going to have to find

  6. ALS History: The First 20 Years

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

    History: The First 20 Years Print Below is an interactive timeline covering highlights of the first 20 years of ALS history. By no means exhaustive, it is meant to provide a broad overview of the people and events that have helped shape the ALS as well as a sense of the breadth of the science that has been done here. Click on items to see more detail. Slide the blue rectangle at bottom to move forward or backward in time. Color Key: Science Highlights (green); People and Events (orange);

  7. GA-AL-SC | Department of Energy

    Energy Savers [EERE]

    GA-AL-SC GA-AL-SC October 1, 2012 ALA-1-N Wholesale Power Rate Schedule Area: PowerSouth Energy Cooperative System: Georgia-Alabama-South Carolina October 1, 2012 Duke-1-E Wholesale Power Rate Schedule Area: Duke On-System System: Georgia-Alabama-South Carolina October 1, 2012 Duke-2-E Wholesale Power Rate Schedule Area: Central System: Georgia-Alabama-South Carolina October 1, 2012 Duke-3-E Wholesale Power Rate Schedule Area: None System: Georgia-Alabama-South Carolina October 1, 2012 Duke-4-E

  8. Microsoft Word - AL2005-01.doc

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

    Acquisition Letters (AL) that remain in effect are identified below. All other previously issued ALs have been superseded by a formal rule-making, incorporated into other guidance, and/or canceled. * * * * * * * * * * * * * * * ACQUISITION LETTERS REMAINING IN EFFECT NUMBER DATE SUBJECT 93-4 04/07/93 Displaced Workers Benefits Program 94-19 12/09/94 Basic Labor Policies Fringe Benefits 95-06 06/28/95 Personal Property Letter System 95-14 11/17/95 Subcontracts under the New Independent States -

  9. Microsoft Word - AL2006-08.doc

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

    Acquisition Letters (AL) that remain in effect are identified below. All other previously issued ALs have been superseded by a formal rule-making, incorporated into other guidance, and/or canceled. * * * * * * * * * * * * * * * ACQUISITION LETTERS REMAINING IN EFFECT NUMBER DATE SUBJECT 93-4 04/07/93 Displaced Workers Benefits Program 94-19 12/09/94 Basic Labor Policies Fringe Benefits 95-06 06/28/95 Personal Property Letter System 95-14 11/17/95 Subcontracts under the New Independent States -

  10. Caribou Biosciences Has Roots at the ALS

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

    Caribou Biosciences Has Roots at the ALS Caribou Biosciences Has Roots at the ALS Print Monday, 15 September 2014 11:01 When Rachel Haurwitz joined UC Berkeley biology professor Jennifer Doudna's lab in 2007 as a graduate student, little did the two women know that the interesting bacterial immune system they were studying would be the subject of news headlines and the basis for a biotech startup just a few years later. It turned out that the bacterial immune system they were studying, known as

  11. Field Mapping At Dixie Valley Geothermal Area (Smith, Et Al....

    Open Energy Info (EERE)

    Smith, Et Al., 2001) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Field Mapping At Dixie Valley Geothermal Area (Smith, Et Al., 2001)...

  12. Acquisitlon Letter No. AL 2008-06 | Department of Energy

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

    AL 2008-06 Acquisitlon Letter No. AL 2008-06 Subject: Domestic and Foreign Procurement Preference Requirements References: FAR Part 25 - Foreign Acquisition DEAR Part 925 - Foreign ...

  13. Moore Foundation Funds ALS Researchers for Promising New Technique...

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

    Moore Foundation Funds ALS Researchers for Promising New Technique for Studying Materials Moore Foundation Funds ALS Researchers for Promising New Technique for Studying Materials...

  14. Fluid Inclusion Analysis At Geysers Area (Moore, Et Al., 2001...

    Open Energy Info (EERE)

    Area (Moore, Et Al., 2001) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Fluid Inclusion Analysis At Geysers Area (Moore, Et Al., 2001)...

  15. Field Mapping At Chena Geothermal Area (Waring, Et Al., 1917...

    Open Energy Info (EERE)

    Waring, Et Al., 1917) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Field Mapping At Chena Geothermal Area (Waring, Et Al., 1917) Exploration...

  16. Radiometrics At Salt Wells Area (Henkle, Et Al., 2005) | Open...

    Open Energy Info (EERE)

    Henkle, Et Al., 2005) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Radiometrics At Salt Wells Area (Henkle, Et Al., 2005) Exploration Activity...

  17. Observation Wells At Lightning Dock Area (Warpinski, Et Al.,...

    Open Energy Info (EERE)

    Area (Warpinski, Et Al., 2004) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Observation Wells At Lightning Dock Area (Warpinski, Et Al., 2004)...

  18. ALS Gives Chevron Scientists New Insights into Corrosion Resistance

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

    ALS Gives Chevron Scientists New Insights into Corrosion Resistance ALS Gives Chevron Scientists New Insights into Corrosion Resistance Print Thursday, 25 July 2013 13:44 In the...

  19. Electronic circuits having NiAl and Ni.sub.3 Al substrates

    DOE Patents [OSTI]

    Deevi, Seetharama C. (Midlothian, VA); Sikka, Vinod K. (Oak Ridge, TN)

    1999-01-01

    An electronic circuit component having improved mechanical properties and thermal conductivity comprises NiAl and/or Ni.sub.3 Al, upon which an alumina layer is formed prior to applying the conductive elements. Additional layers of copper-aluminum alloy or copper further improve mechanical strength and thermal conductivity.

  20. The Impact of Aluminum and Iron Substitution on the Structure and Electrochemistry of Li[Ni0.4Co0.2-yMyMn0.4]O2 Materials

    SciTech Connect (OSTI)

    WIlcox, James D.; Rodriguez, Efrain E.; Doeff, Marca M.

    2009-07-23

    Li[Ni0.4Co0.2-yMyMn0.4]O2 (0<_y<_0.2) (M=Al) and Li[Ni0.4Co0.15Fe0.05Mn0.4]O2 compounds were prepared in order to investigate the effect of replacement of all or part of the cobalt on the structural and electrochemical properties. The impact of substitution on the structure has been examined by both x-ray and neutron diffraction experiments. The incorporation of aluminum has minimal effect on the anti-site defect concentration, but leads to structural changes that affect electrochemical performance. The most important effect is an opening of the lithium slab dimension upon substitution, which results in improved rate performance compared to the parent compound. In contrast, the lithium slab dimension is not affected by iron substitution and no rate enhancement effect is observed. The cycling stability of aluminum containing materials is superior to both the parent material and iron-substituted materials.

  1. Zn13(CrxAl1-x)27 (x = 0.34-0.37): a new intermetallic phase containing icosahedra as building units

    SciTech Connect (OSTI)

    Thimmaiah, Srinivasa; Han, Mi-Kyung; Miller, Gordon J.

    2011-03-13

    The title compounds Zn{sub 13}(Cr{sub x}Al{sub 1-x}){sub 27} (x = 0.34-0.37) were obtained by melting the pure elements at 923 K, and followed by a heat treatment at 723 K in a tantalum container. According to single crystal structural analysis, the title compounds crystallize in the rhombohedral system, adopting a new structure type (R-3m, a = 7.5971(8), c = 36.816(6), for crystal I). Single crystal X-ray structural analysis reveals a statistical mixing of Cr/Al in their crystallographic positions. Single crystal and powder X-ray diffraction as well as energy dispersive X-ray analyses suggested the title phase to have a narrow homogeneity range. The substructure of Zn{sub 13}(Cr{sub x}Al{sub 1-x}){sub 27} shows close resemblance with the Mn{sub 3}Al{sub 10} structure type. A bonding analysis, through crystal orbital Hamiltonian populations (COHPs), of 'Cr{sub 9}Al{sub 18}Zn{sub 13}' as a representative composition indicated that both homo- and heteronuclear interactions are important for the stability of this new phase.

  2. m/sup +/SR studies on pure MnF/sub 2/ and site-diluted (Mn/sub 0. 5/Zn/sub 0. 5/)F/sub 2/

    SciTech Connect (OSTI)

    Uemura, Y.J.; Keitel, R.; Senba, M.; Kiefl, R.F.; Kreitzman, S.R.; Noakes, D.R.; Brewer, J.H.; Harshman, D.R.; Ansaldo, E.J.; Crowe, K.M.

    1986-01-01

    Positive muon spin rotation and relaxation measurements have been carried out on the antiferromagnets, pure MnF/sub 2/ and site-diluted (Mn/sub 0.5/Zn/sub 0.5/)F/sub 2/, above and below the Neel temperature T/sub N/ using single-crystal specimens. Two different muon signals have been found in the pure MnF/sub 2/; with the precession frequency nu/sub A/ = 1.3 GHz for the site A and nu/sub B/ = 152 MHz for the site B measured in zero external magnetic field at T = 5 K. We propose a picture that the signal from the A site represents the ''muonium'' state, and discuss the characteristic features of muonium in magnetic materials. The spin relaxation rate 1/T/sub 1/, measured in zero external field, decreases rapidly with decreasing temperature below T/sub N/. The mechanism of the spin relaxation above T/sub N/ is explained by the exchange fluctuations of the Mn moments, while below T/sub N/ by the Raman scattering of spin waves. At the same normalized temperature T/T/sub N/, 1/T/sub 1/ observed in the diluted (Mn/sub 0.5/Zn/sub 0.5/)F/sub 2/ is significantly larger than that in the pure MnF/sub 2/ below T/sub N/. The difference between the pure and diluted systems is related to the large spectral weight of low-energy magnons in (Mn/sub 0.5/Zn/sub 0.5/)F/sub 2/ found by neutron scattering.

  3. Alloy inhomogeneity and carrier localization in AlGaN sections and AlGaN/AlN nanodisks in nanowires with 240350?nm emission

    SciTech Connect (OSTI)

    Himwas, C.; Hertog, M. den; Dang, Le Si; Songmuang, R.; Monroy, E.

    2014-12-15

    We present structural and optical studies of AlGaN sections and AlGaN/AlN nanodisks (NDs) in nanowires grown by plasma-assisted molecular beam epitaxy. The Al-Ga intermixing at Al(Ga)N/GaN interfaces and the chemical inhomogeneity in AlGaN NDs evidenced by scanning transmission electron microscopy are attributed to the strain relaxation process. This interpretation is supported by the three-dimensional strain distribution calculated by minimizing the elastic energy in the structure. The alloy inhomogeneity increases with the Al content, leading to enhanced carrier localization signatures in the luminescence characteristics, i.e., red shift of the emission, s-shaped temperature dependence, and linewidth broadening. Despite these effects, the emission energy of AlGaN/AlN NDs can be tuned in the 240350?nm range with internal quantum efficiencies around 30%.

  4. Ternary Dy-Er-Al magnetic refrigerants

    DOE Patents [OSTI]

    Gschneidner, Jr., Karl A.; Takeya, Hiroyuki

    1995-07-25

    A ternary magnetic refrigerant material comprising (Dy.sub.1-x Er.sub.x)Al.sub.2 for a magnetic refrigerator using the Joule-Brayton thermodynamic cycle spanning a temperature range from about 60K to about 10K, which can be adjusted by changing the Dy to Er ratio of the refrigerant.

  5. Ternary Dy-Er-Al magnetic refrigerants

    DOE Patents [OSTI]

    Gschneidner, K.A. Jr.; Takeya, Hiroyuki

    1995-07-25

    A ternary magnetic refrigerant material comprising (Dy{sub 1{minus}x}Er{sub x})Al{sub 2} for a magnetic refrigerator using the Joule-Brayton thermodynamic cycle spanning a temperature range from about 60K to about 10K, which can be adjusted by changing the Dy to Er ratio of the refrigerant. 29 figs.

  6. Neutron powder diffraction analysis of (Tm{sub 0.50}Ca{sub 0.50})MnO{sub 3}

    Office of Scientific and Technical Information (OSTI)

    and (Lu{sub 0.50}Ca{sub 0.50})MnO{sub 3} (Journal Article) | SciTech Connect SciTech Connect Search Results Journal Article: Neutron powder diffraction analysis of (Tm{sub 0.50}Ca{sub 0.50})MnO{sub 3} and (Lu{sub 0.50}Ca{sub 0.50})MnO{sub 3} Citation Details In-Document Search Title: Neutron powder diffraction analysis of (Tm{sub 0.50}Ca{sub 0.50})MnO{sub 3} and (Lu{sub 0.50}Ca{sub 0.50})MnO{sub 3} The crystal and magnetic structures of (Tm{sub 0.50}Ca{sub 0.50})MnO{sub 3} and (Lu{sub

  7. Recovery of oscillatory magneto-resistance in phase separated La{sub 0.3}Pr{sub 0.4}Ca{sub 0.3}MnO{sub 3} epitaxial thin films

    SciTech Connect (OSTI)

    Alagoz, H. S., E-mail: alagoz@ualberta.ca; Jeon, J.; Mahmud, S. T.; Saber, M. M.; Chow, K. H., E-mail: khchow@ualberta.ca; Jung, J., E-mail: jjung@ualberta.ca [Department of Physics, University of Alberta, Edmonton, Alberta T6G 2E1 (Canada); Prasad, B. [Department of Materials Science and Metallurgy, University of Cambridge, Cambridge CB2 3QZ (United Kingdom)] [Department of Materials Science and Metallurgy, University of Cambridge, Cambridge CB2 3QZ (United Kingdom); Egilmez, M. [Department of Physics, American University of Sharjah, Sharjah (United Arab Emirates)] [Department of Physics, American University of Sharjah, Sharjah (United Arab Emirates)

    2013-12-02

    In-plane angular dependent magneto-resistance has been studied in La{sub 0.3}Pr{sub 0.4}Ca{sub 0.3}MnO{sub 3} (LPCMO) manganite thin films deposited on the (100) oriented NdGaO{sub 3}, and (001) oriented SrTiO{sub 3} and LaAlO{sub 3} substrates. At temperatures where the electronic phase separation is the strongest, a metastable irreversible state exists in the films whose resistivity ? attains a large time dependent value. The ? decreases sharply with an increasing angle ? between the magnetic field and the current, and does not display an expected oscillatory cos{sup 2}?/sin{sup 2}? dependence for all films. The regular oscillations are recovered during repetitive sweeping of ? between 0 and 180. We discuss possible factors that could produce these unusual changes in the resistivity.

  8. Structure and magnetic properties of Ba{sub 5}Ce{sub 1.25}Mn{sub 3.75}O{sub 15}, a new 10H-polytype in the Ba-Ce-Mn-O system

    SciTech Connect (OSTI)

    Macias, Mario A.; Mentre, Olivier; Cuello, Gabriel J.; Gauthier, Gilles H.

    2013-02-15

    Based on the peculiar magnetic properties that are observed in pseudo one-dimensional manganites, we decided to synthesize the new Ba{sub 5}Ce{sub 1.25}Mn{sub 3.75}O{sub 15} compound. The preparation was performed by solid state reaction in air at about 1350 Degree-Sign C, for which we found that the compound crystallizes in a hexagonal symmetry with space group P6{sub 3}/mmc (No-194) and cell parameters a=b=5.7861(2) A and c=23.902(1) A. The structural description was correlated with neutron diffraction and bond valence calculations, confirming the presence of Ce{sup 4+} and Mn{sup 4+} segregated in the different crystallographic positions. Ba{sub 5}Ce{sub 1.25}Mn{sub 3.75}O{sub 15} displays evidence for strong AFM couplings already set at room temperature. The main arrangement of Mn{sup 4+} in magnetically isolated tetramers of face-sharing octahedra is responsible for a metamagnetic-like transition around 50 K. - Graphical abstract: The new Ba{sub 5}Ce{sub 1.25}Mn{sub 3.75}O{sub 15} polytype shows strong AFM couplings in magnetically isolated [Ce{sub 0.25}Mn{sub 3.75}O{sub 15}] tetramers of face-sharing octahedral, resulting in a metamagnetic-like transition around 50 K. Highlights: Black-Right-Pointing-Pointer Ba{sub 5}Ce{sub 1.25}Mn{sub 3.75}O{sub 15}, a new 10H polytype, has been prepared in the Ba-Ce-Mn-O system. Black-Right-Pointing-Pointer The compound crystallizes in the P6{sub 3}/mmc space group with (cchhh){sub 2} stacking sequence. Black-Right-Pointing-Pointer [Ce{sub 0.25}Mn{sub 3.75}O{sub 15}] tetramers are separated by [CeO{sub 6}] octahedra in the structure. Black-Right-Pointing-Pointer Instead of robust AFM ordering, a metamagnetic-like transition is found around 50 K.

  9. In situ and ex situ spectroelectrochemical and X-ray absorption studies on rechargeable, chemically-modified and other MnO{sub 2} materials

    SciTech Connect (OSTI)

    Conway, B.E.; Qu, D.; McBreen, J. |

    1992-12-31

    A combined series of in situ and ex situ UV spectroelectrochemical and X-ray absorption studies have been made on MnO{sub 2}, chemically-modified by small amounts of Bi(III), and comparatively on other MnO{sub 2} materials such as a blank (Bi-free) and {gamma}-MnO{sub 2}. These procedures are applied in order to follow the oxidation-states of Bi and of Mn during the course of discharge and recharge of MnO{sub 2} as a battery cathode material, and the extents of rechargeability that can be achieved with such materials. Presence of Bi appears to provide a preferred ``heterogeneous`` discharge/recharge pathway involving a soluble Mn(III) intermediate, over the alternative ``electron-proton`` hopping, solid-state mechanism. From XAS results, it is concluded that presence of Bi, although not affecting the O-coordination, does influence the Mn-Mn coordination, determining the way the MnO{sub 2} coordination octahedra are connected.

  10. Mixed metallic Ba(Co,Mn)X{sub 0.2-x}O{sub 3-{delta}} (X=F, Cl) hexagonal perovskites

    SciTech Connect (OSTI)

    Iorgulescu, Mihaela; Roussel, Pascal; Tancret, Nathalie; Renaut, Nicolas; Tiercelin, Nicolas; Mentre, Olivier

    2013-02-15

    We show here that the incorporation of Mn in Ba-Co-oxohalide, BaCoX{sub 0.2-x}O{sub 3-{delta}}, hexagonal perovskite stabilizes the 6H-form (stacking sequence (chhhch Prime ); c, h=[BaO{sub 3}] and h Prime =[BaOX] layers), with tetramers of face-sharing octahedra) rather than the trimeric 10H-form. On the contrary to previous results on the Fe incorporation in similar system leading to more reduced 10H-compounds, the Mn effect is to increase the mean (Co/Mn) valence better suited to the 6H form. We experienced a poor Mn/Co miscibility during our syntheses leading to great difficulties to isolate mixed Co/Mn single phase materials and/or weak reproducibility. Powder neutron diffraction data shows a mixed Mn/Co octahedral occupancy, while the tetrahedra are filled by Co{sup 3+} cations. Anionic vacancies were refined in the h Prime -[BaO{sub 1-z}X{sub 1-x}] layer and the next c-[BaO{sub 3-z}] layers, while the h-[BaO{sub 3}] layers are not oxygen deficient. Magnetic properties suggest that a part of Mn cations remain paramagnetic until low temperature, while isolated spin clusters (probably driven by AFM Co tetrahedral dimers) behave as low-dimensional AFM systems. Transport measurements reveal a transition from high-temperature metallic to low-temperature semi-conducting states that could occur from defect shallow donor upon the Mn for Co substitution. - Graphical abstract: The incorporation of Mn in Ba-Co-oxohalide, BaCoX{sub 0.2-x}O{sub 3-{delta}}, hexagonal perovskite stabilizes the 6H-form with tetrameric (Co,Mn){sub 4}O{sub 15} face sharing linear chains. This results from a oxidizing Mn effect and particular Mn/Co distribution. Highlights: Black-Right-Pointing-Pointer The incorporation of Mn in BaCoX{sub 0.2-x}O{sub 3-{delta}} (X=F,Cl) hexagonal perovskites stabilizes the 6H-form. Black-Right-Pointing-Pointer It contains tetrameric (Co,Mn){sub 4}O{sub 15} face sharing linear chains. Black-Right-Pointing-Pointer The preference for such chains better than trimeric ones is due to the Manganese oxidizing effect. Black-Right-Pointing-Pointer A particular Mn/Co distribution was evidenced. Black-Right-Pointing-Pointer Transport and magnetic properties drastically change during the Mn incorporation.

  11. Probing The Electrode/Electrolyte Interface in The Lithium Excess Layered Oxide Li1.2Ni0.2Mn0.6O2

    SciTech Connect (OSTI)

    Carroll, Kyler J; Qian, Danna; Fell, Chris; Calvin, Scott; Veith, Gabriel M; Chi, Miaofang; Dudney, Nancy J; Meng, Ying Shirley

    2013-01-01

    A detailed surface investigation of the lithium-excess nickel manganese layered oxide Li1.2Ni0.2Mn0.6O2 structure was carried out using x-ray photoelectron spectroscopy (XPS), total electron yield and transmission x-ray absorption spectroscopy (XAS), and electron energy loss spectroscopy (EELS) during the first two electrochemical cycles. All spectroscopy techniques consistently showed the presence of Mn4+ in the pristine material and a surprising reduction of Mn at the voltage plateau during the first charge. The Mn reduction is accompanied by the oxygen loss revealed by EELS. Upon the first discharge, the Mn at the surface never fully returns back to Mn4+. The electrode/electrolyte interface of this compound consists of the reduced Mn at the crystalline defect-spinel inner layer and an oxidized Mn species simultaneously with the presence of a superoxide species in amorphous outer layer. This proposed model signifies that oxygen vacancy formation and lithium removal result in electrolyte decomposition and superoxide formation, leading to Mn activation/dissolution and surface layer-spinel phase transformation. The results also indicate that the role of oxygen is complex and significant in contributing to the extra capacity of this class of high energy density cathode materials.

  12. Microsoft Word - al2004-03.doc | Department of Energy

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

    al2004-03.doc Microsoft Word - al2004-03.doc PDF icon Microsoft Word - al2004-03.doc More Documents & Publications Acquisition Letter: AL2005-08 OPAM Policy Acquisition Guides Presentations, Women-Owned Small Business Forum (May 2013)

  13. Microsoft Word - al2005-04.doc | Department of Energy

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

    al2005-04.doc Microsoft Word - al2005-04.doc PDF icon Microsoft Word - al2005-04.doc More Documents & Publications AL2005-04ClassDeviation.pdf Microsoft Word - Matrixpart2.doc 2014-02 Acquistion Letter 2014-01: Management and Operating Contractors' Audit Coverage of Cost-Reimbursement Subcontracts

  14. Microsoft Word - AL2005-03.doc | Department of Energy

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

    3.doc Microsoft Word - AL2005-03.doc PDF icon Microsoft Word - AL2005-03.doc More Documents & Publications Microsoft Word - AL2005-01.doc Microsoft Word - AL2006-08.doc Microsoft Word - Chapter 10_2006_Jun

  15. Microsoft Word - AL2007-01.doc | Department of Energy

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

    AL2007-01.doc Microsoft Word - AL2007-01.doc PDF icon Microsoft Word - AL2007-01.doc More Documents & Publications Microsoft Word - Rev5functionalaccountabilityimplementationplan..doc Microsoft Word - Corp Impl 10-05-06.final.doc Microsoft Word - AL2006-11.doc

  16. Al2000-12.pdf | Department of Energy

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

    Al2000-12.pdf Al2000-12.pdf PDF icon Al2000-12.pdf More Documents & Publications AL2007-02.doc&0; Audit Report: OAS-L-07-17 Audit Report: OAS-L-07-18...

  17. Acquisition Letter No. AL 2014-01 | Department of Energy

    Energy Savers [EERE]

    Letter No. AL 2014-01 Acquisition Letter No. AL 2014-01 PDF icon AL 2014-01.pdf More Documents & Publications Assessment Report: OAI-V-16-03 Assessment Report: OAI-V-16-05 Acquisition Letter No. AL 2012-05

  18. AL2010-03.pdf | Department of Energy

    Energy Savers [EERE]

    AL2010-03.pdf AL2010-03.pdf PDF icon AL2010-03.pdf More Documents & Publications Financial Assistance Letter No. FAL 2010-03 Policy Flash 2015-29 - AL 2015-06 - FAL 2015-04 Before the House Oversight and Government Reform Subcommittee on Technology, Information Policy, Intergovernmental Relations, and Procurement Reform

  19. Microsoft Word - AL2005-12.doc | Department of Energy

    Energy Savers [EERE]

    2.doc Microsoft Word - AL2005-12.doc PDF icon Microsoft Word - AL2005-12.doc More Documents & Publications Acquisition Letter No. AL 2012-05 Microsoft Word - AL2005-11.doc OPAM Policy Acquisition Guides

  20. AL/FAL 99-01 | Department of Energy

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

    AL/FAL 99-01 AL/FAL 99-01 PDF icon AL/FAL 99-01 More Documents & Publications Department of Energy No Microsoft Word - FAL2004-01.doc Microsoft Word - AL2000-01.doc

  1. AL2007-05.doc | Department of Energy

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

    7-05.doc&#0; AL2007-05.doc&#0; PDF icon AL2007-05.doc&#0; More Documents & Publications Microsoft Word - AL2006-08.doc Department of Energy Microsoft Word - AL2006-10.doc

  2. Microsoft Word - AL2003-04.doc | Department of Energy

    Office of Environmental Management (EM)

    3-04.doc Microsoft Word - AL2003-04.doc PDF icon Microsoft Word - AL2003-04.doc More Documents & Publications Microsoft Word - AL2006-08.doc AL2004-01r2.pdf City of Tulare Renewable Biogas Fuel Cell Project

  3. Microsoft Word - AL2005-01.doc | Department of Energy

    Office of Environmental Management (EM)

    1.doc Microsoft Word - AL2005-01.doc PDF icon Microsoft Word - AL2005-01.doc More Documents & Publications Microsoft Word - AL2006-08.doc Acquisition Letter Archive listing AL2007-05.doc&#0;

  4. Acquisition Letter: AL2005-08 | Department of Energy

    Energy Savers [EERE]

    Letter: AL2005-08 Acquisition Letter: AL2005-08 June 10, 2005 Acquisition Letter: AL2005-08 - Small Business Programs This Acquisition Letter is issued under the authority of the DOE and NNSA Procurement Executives. This AL remains in effect until superseded or canceled. This AL supersedes AL-2004-03 (Small Business Programs, dated May 5, 2004), which is rescinded in its entirety. PDF icon Microsoft Word - AL2005-08.doc More Documents & Publications OPAM Policy Acquisition Guides Microsoft

  5. Phase transformation during mechano-synthesis of nanocrystalline/amorphous Fe32Mn6Si alloys

    SciTech Connect (OSTI)

    Amini, Rasool; Shamsipoor, Ali; Ghaffari, Mohammad; Alizadeh, Morteza; Okyay, Ali Kemal

    2013-10-15

    Mechano-synthesis of Fe32Mn6Si alloy by mechanical alloying of the elemental powder mixtures was evaluated by running the ball milling process under an inert argon gas atmosphere. In order to characterize the as-milled powders, powder sampling was performed at predetermined intervals from 0.5 to 192 h. X-ray florescence analyzer, X-ray diffraction, scanning electron microscope, and high resolution transmission electron microscope were utilized to investigate the chemical composition, structural evolution, morphological changes, and microstructure of the as-milled powders, respectively. According to the results, the nanocrystalline FeMnSi alloys were completely synthesized after 48 h of milling. Moreover, the formation of a considerable amount of amorphous phase during the milling process was indicated by quantitative X-ray diffraction analysis as well as high resolution transmission electron microscopy image and its selected area diffraction pattern. It was found that the ?-to-? and subsequently the amorphous-to-crystalline (especially martensite) phase transformation occurred by milling development. - Graphical abstract: Mechano-synthesis of nanocrystalline/amorphous Fe32Mn6Si shape memory alloys in the powder form: amorphous phase formation, ?-to-? phase transformation, mechano-crystallization of the amorphous, and martensite phase formation during the process. Highlights: During MA, the ?-to-? phase transformation and amorphization occurred. Mechano-crystallization of the amorphous phase occurred at sufficient milling time. The formation of high amount of ?-martensite was evidenced at high milling times. The platelet, spherical, and then irregular particle shapes was extended by MA. By MA, the particles size was increased, then reduced, and afterward re-increased.

  6. Structural and Chemical Evolution of Li- and Mn-rich Layered Cathode Material

    SciTech Connect (OSTI)

    Zheng, Jianming; Xu, Pinghong; Gu, Meng; Xiao, Jie; Browning, Nigel D.; Yan, Pengfei; Wang, Chong M.; Zhang, Jiguang

    2015-02-24

    Lithium (Li)- and manganese-rich (LMR) layered-structure materials are very promising cathodes for high energy density lithium-ion batteries. However, their voltage fading mechanism and its relationships with fundamental structural changes are far from being sufficiently understood. Here we report the detailed phase transformation pathway in the LMR cathode (Li[Li0.2Ni0.2Mn0.6]O2) during cycling for the samples prepared by hydro-thermal assistant method. It is found the transformation pathway of LMR cathode is closely correlated to its initial structure and preparation conditions. The results reveal that LMR cathode prepared by HA approach experiences a phase transformation from the layered structure to a LT-LiCoO2 type defect spinel-like structure (Fd-3m space group) and then to a disordered rock-salt structure (Fm-3m space group). The voltage fade can be well correlated with the Li ion insertion into octahedral sites, rather than tetrahedral sites, in both defect spinel-like structure and disordered rock-salt structure. The reversible Li insertion/removal into/from the disordered rock-salt structure is ascribed to the Li excess environment that can satisfy the Li percolating in the disordered rock-salt structure despite the increased kinetic barrier. Meanwhile, because of the presence of a great amount of oxygen vacancies, a significant decrease of Mn valence is detected in the cycled particle, which is below that anticipated for a potentially damaging Jahn-Teller distortion (+3.5). Clarification of the phase transformation pathway, cation redistribution, oxygen vacancy and Mn valence change undoubtedly provides insights into a profound understanding on the voltage fade, and capacity degradation of LMR cathode. The results also inspire us to further enhance the reversibility of LMR cathode via improving its surface structural stability.

  7. Acquisition letter No. AL 2015-05 | Department of Energy

    Energy Savers [EERE]

    letter No. AL 2015-05 Acquisition letter No. AL 2015-05 DATE: May 12, 2015 TO: Procurement Directors/Contracting Officers FROM: Director Contract and Financial Assistance Policy Division Office of Policy Office of Acquisition and Project Management SUBJECT: Acquisition Letters Remaining in Effect SUMMARY: Acquisition letter 2015-05 has been issued. It lists ALs currently in effect and the discontinued ALs, along with the reason why the AL is no longer in effect. This Flash will be available

  8. DOE - Office of Legacy Management -- Tennessee Valley Authority - AL 01

    Office of Legacy Management (LM)

    Tennessee Valley Authority - AL 01 FUSRAP Considered Sites Site: TENNESSEE VALLEY AUTHORITY (AL.01 ) Eliminated from consideration under FUSRAP Designated Name: Not Designated Alternate Name: None Location: Muscle Shoals , Alabama AL.01-1 Evaluation Year: 1987 AL.01-2 Site Operations: Performed research and development during the early 1950s at an onsite lab and pilot plant on a process to recover uranium during the production of phosphate fertilizer. AL.01-1 Site Disposition: Eliminated -

  9. Electronic transport through Al/InN nanowire/Al junctions (Journal...

    Office of Scientific and Technical Information (OSTI)

    T 0.3 K, below the superconducting transition temperature of the Al electrodes. The proximity effect is observed in these devices through a strong dip in resistance at zero bias. ...

  10. OP-AL-0002-001.PDF

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

    Doc. ID: OP-AL-0002-001.doc Caretaker Date: 2000/08/03 This authorized list is effective 08/03/2000 and specifies those individuals who have been authorized for Caretaker Operation 1. Aigeldinger, Georg 2. Bucher, Stephanie 3. Choi, Jaewu 4. Koch, Kevin 5. Lian, Kun 6. Ling, Zhong Geng 7. Manohara, Harish 8. Morikawa, Eizi 9. Palshin, Vadim 10. Rupp, Louis 11. Schoonmaker, Mike 12. Scott, John 13. Sprunger, Phil 14. Tittsworth, Roland 15. Xu, Jie Authorization: ________________ ________

  11. OP-AL-0003-001.PDF

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

    Doc. ID: OP-AL-0003-001.doc Accelerator Operators Date: 2000/08/03 This document is effective 08/4/2000 and specifies those individuals who are authorized to operate the Electron Accelerators at CAMD. 1. Ben Craft 2. Larry Oliszwesky 3. Paul Jines 4. Don Patterson 5. Yongzhang Huang Authorization: ____________________ ________ ____________________ ________ F. Josef Hormes Date Benjamin Craft III Date ____________________ ________ Lorraine Marceau-Day

  12. Caribou Biosciences Has Roots at the ALS

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

    Caribou Biosciences Has Roots at the ALS Print When Rachel Haurwitz joined UC Berkeley biology professor Jennifer Doudna's lab in 2007 as a graduate student, little did the two women know that the interesting bacterial immune system they were studying would be the subject of news headlines and the basis for a biotech startup just a few years later. It turned out that the bacterial immune system they were studying, known as CRISPR (clustered regularly interspaced short palindromic repeats), has a

  13. Microsoft Word - al93-4.doc

    Energy Savers [EERE]

    93-4 Acquisition Regulation Date April 7, 1993 ACQUISITION LETTER AUTHORITY This Acquisition Letter (AL) is issued by the Director, Office of Procurement, Assistance and Program Management, pursuant to a delegation from the Secretary and under the authority of the Department of Energy Acquisition Regulation (DEAR) Subpart 901.301-70. ***************************************************************** CONTENTS CITATION TITLE DEAR 970.3102-2Compensation for personal services DEAR 970.3102-2(i)

  14. Microsoft Word - al94-19.doc

    Energy Savers [EERE]

    AUTHORITY This Acquisition Letter is issued by the Procurement Executive pursuant to a delegation from the Secretary and under the authority of the Department of Energy Acquisition Regulation (DEAR) Subpart 901.301-70. ***************************************************************************** CONTENT CITATION TITLE DEAR 970.2201 Basic labor policies DEAR 970.3102-2(n) Fringe benefits I. Purpose. The purpose of this Acquisition Letter (AL) is to (1) clarify the Department of Energy (DOE)

  15. Microsoft Word - AL2005-03.doc

    Office of Environmental Management (EM)

    AL 2005-03 Acquisition Regulation Date 10/08/04 ACQUISITION LETTER This Acquisition Letter is issued under the authority of the DOE and NNSA Procurement Executives. Subject: Independent Peer Review Program for Contractors' Purchasing Systems References: FAR 44.3, Contractors' Purchasing Systems Reviews DEAR Subpart 970.44 - Management and Operating Contractor Purchasing DOE Acquisition Guide, Chapter 1.2, Balanced Scorecard Performance Assessment Program (DOE only) DOE Acquisition Guide, Chapter

  16. Microsoft Word - AL2006-07.doc

    Office of Environmental Management (EM)

    Department of Energy No. AL-2006-07 Acquisition Regulation Date 08/23/06 ACQUISITION LETTER This Acquisition Letter is issued by the Procurement Executives of DOE and NNSA. Subject: DOE Order 361.1A, Acquisition Career Development Program References: DOE O 361.1A, Acquisition Career Development (ACD) Program Office of Federal Procurement Policy (OFPP) Policy Letter 05-01, Developing and Managing the Acquisition Workforce OFPP Policy Letter 06-01 OFPP Memoranda, The Federal Acquisition

  17. Generation and control of spin-polarized photocurrents in GaMnAs heterostructures

    SciTech Connect (OSTI)

    Bezerra, Anibal T. Farinas, Paulo F.; Studart, Nelson; Degani, Marcos H.; Maialle, Marcelo Z.

    2014-01-13

    Photocurrents are calculated for a specially designed GaMnAs semiconductor heterostructure. The results reveal regions in the infrared range of the energy spectrum, in which the proposed structure is remarkably spin-selective. For such photon energies, the generated photocurrents are strongly spin-polarized. Application of a relatively small static bias in the growth direction of the structure is predicted to efficiently reverse the spin-polarization for some photon energies. This behavior suggests the possibility of conveniently simple switching mechanisms. The physics underlying the results is studied and understood in terms of the spin-dependent properties emerging from the particular potential profile of the structure.

  18. Magnetocrystalline Anisotropy in UMn2Ge2 and Related Mn-based Actinide Ferromagnets

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

    Parker, David S; Mandrus, D.; Ghimire, N J; Baumbach, Ryan; Singleton, John; Thompson, J.D.; Bauer, Eric D.; Li, Ling; Singh, David J

    2015-01-01

    We present magnetization isotherms in pulsed magnetic fields up to 62 Tesla, supported by first principles calculations, demonstrating a huge uniaxial magnetocrystalline anisotropy energy - approximately 20 MJ/m3 - in UMn2Ge2. This large anisotropy results from the extremely strong spin-orbit coupling affecting the uranium 5 f electrons, which in the calculations exhibit a substantial orbital moment exceeding 2 Bohr magnetons. We also find from theoretical calculations that a number of isostructural Mn-actinide compounds are expected to have similarly large anisotropy.

  19. Vacancy dynamic in Ni-Mn-Ga ferromagnetic shape memory alloys

    SciTech Connect (OSTI)

    Merida, D.; Snchez-Alarcos, V.; Prez-Landazbal, J. I.; Recarte, V.; Plazaola, F.

    2014-06-09

    Vacancies control any atomic ordering process and consequently most of the order-dependent properties of the martensitic transformation in ferromagnetic shape memory alloys. Positron annihilation spectroscopy demonstrates to be a powerful technique to study vacancies in NiMnGa alloys quenched from different temperatures and subjected to post-quench isothermal annealing treatments. Considering an effective vacancy type the temperature dependence of the vacancy concentration has been evaluated. Samples quenched from 1173?K show a vacancy concentration of 1100??200?ppm. The vacancy migration and formation energies have been estimated to be 0.55??0.05?eV and 0.90??0.07?eV, respectively.

  20. Direct evidence of detwinning in polycrystalline Ni-Mn-Ga ferromagnetic shape memory alloys during deformation.

    SciTech Connect (OSTI)

    Nie, Z. H.; Lin Peng, R.; Johansson, S.; Oliver, E. C.; Ren, Y.; Wang, Y. D.; Liu, Y. D.; Deng, J. N.; Zuo, L.; Brown, D. E.; Northwestern Univ., China; Linkoping Univ.; Rutherford Appleton Lab.; Northern Illinois Univ.

    2008-01-01

    In situ time-of-flight neutron diffraction and high-energy x-ray diffraction techniques were used to reveal the preferred reselection of martensite variants through a detwinning process in polycrystalline Ni-Mn-Ga ferromagnetic shape memory alloys under uniaxial compressive stress. The variant reorientation via detwinning during loading can be explained by considering the influence of external stress on the grain/variant orientation-dependent distortion energy. These direct observations of detwinning provide a good understanding of the deformation mechanisms in shape memory alloys.

  1. Magnetoelastic Coupling and Symmetry Breaking in the Frustrated Antiferromagnet {alpha}-NaMnO{sub 2}

    SciTech Connect (OSTI)

    Giot, Maud; Chapon, Laurent C.; Radaelli, Paolo G.; Androulakis, John; Lappas, Alexandros; Green, Mark A.

    2007-12-14

    The magnetic and crystal structures of the {alpha}-NaMnO{sub 2} have been determined by high-resolution neutron powder diffraction. The system maps out a frustrated triangular spin lattice with anisotropic interactions that displays two-dimensional spin correlations below 200 K. Magnetic frustration is lifted through magneto-elastic coupling, evidenced by strong anisotropic broadening of the diffraction profiles at high temperature and ultimately by a structural phase transition at 45 K. In this low-temperature regime a three-dimensional antiferromagnetic state is observed with a propagation vector k=((1/2),(1/2),0)

  2. Magnetic domain wall manipulation in (Ga,Mn)As nanostructures for spintronic applications

    SciTech Connect (OSTI)

    Wosinski, Tadeusz; Andrearczyk, Tomasz; Figielski, Tadeusz; Olender, Karolina; Wrobel, Jerzy

    2014-02-21

    Ring-shaped 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, in a form of planar rings with a slit, were supplied with four electrical terminals and subjected to magneto-transport studies under planar weak magnetic field. Magnetoresistive effects caused by manipulation of magnetic domain walls and magnetization reversal in the nanostructures have been investigated and possible applications of the nanostructures as four-terminal spintronic devices are discussed.

  3. Half metallic ferromagnetism in alkali metal nitrides MN (M = Rb, Cs): A first principles study

    SciTech Connect (OSTI)

    Murugan, A. Rajeswarapalanichamy, R. Santhosh, M. Sudhapriyanga, G.; Kanagaprabha, S.

    2014-04-24

    The structural, electronic and elastic properties of two alkali metal nitrides (MN: M= Rb, Cs) are investigated by the first principles calculations based on density functional theory using the Vienna ab-initio simulation package. At ambient pressure the two nitrides are stable in ferromagnetic state with CsCl structure. The calculated lattice parameters are in good agreement with the available results. The electronic structure reveals that these materials are half metallic in nature. A pressure-induced structural phase transition from CsCl to ZB phase is observed in RbN and CsN.

  4. HIA 2015 DOE Zero Energy Ready Home Case Study: Amaris Homes, Fishers Circle, Vadnais Heights, MN

    Energy Savers [EERE]

    Homes Fishers Circle Vadnais Heights, MN DOE ZERO ENERGY READY HOME(tm) The U.S. Department of Energy invites home builders across the country to meet the extraordinary levels of excellence and quality specified in DOE's Zero Energy Ready Home program (formerly known as Challenge Home). Every DOE Zero Energy Ready Home starts with ENERGY STAR Certified Homes Version 3.0 for an energy-efficient home built on a solid foundation of building science research. Advanced technologies are designed in to

  5. High Nb, Ta, and Al creep- and oxidation-resistant austenitic stainless steel

    DOE Patents [OSTI]

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

    2010-07-13

    An austenitic stainless steel HTUPS alloy includes, in weight percent: 15 to 30 Ni; 10 to 15 Cr; 2 to 5 Al; 0.6 to 5 total of at least one of Nb and Ta; no more than 0.3 of combined Ti+V; up to 3 Mo; up to 3 Co; up to 1 W; up to 0.5 Cu; up to 4 Mn; up to 1 Si; 0.05 to 0.15 C; up to 0.15 B; 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 wherein said alloy forms an external continuous scale comprising alumina, nanometer scale sized particles distributed throughout the microstructure, said particles comprising at least one composition selected from the group consisting of NbC and TaC, and a stable essentially single phase fcc austenitic matrix microstructure, said austenitic matrix being essentially delta-ferrite-free and essentially BCC-phase-free.

  6. Neutron structural characterization, inversion degree and transport properties of NiMn{sub 2}O{sub 4} spinel prepared by the hydroxide route

    SciTech Connect (OSTI)

    Sagua, A.; Lescano, Gabriela M.; Alonso, J.A.; Martnez-Coronado, R.; Fernndez-Daz, M.T.; Morn, E.

    2012-06-15

    Graphical abstract: A pure specimen has been synthesized by the hydroxide route. This spinel, studied by NPD, shows an important inversion degree, ? = 0.80. A bond-valence study shows that the tetrahedral Mn ions are divalent whereas the octahedral Mn and Ni are slightly oxidized from the expected 3+ and 2+ values, respectively. The mixed valence Mn{sup 3+}/Mn{sup 4+} accounts for a hopping mechanism between adjacent octahedral sites, leading to a significant conductivity. Highlights: ? A low-temperature hydroxide route allowed preparing almost pure specimens of NiMn{sub 2}O{sub 4}. ? NPD essential to determine inversion degree; contrasting Ni and Mn for neutrons. ? Bond valence establishes valence state of octahedral and tetrahedral Ni and Mn ions. ? Thermal analysis, transport measurements complement characterization of this oxide. ? A structureproperties relationship is established. -- Abstract: The title compound has been synthesized by the hydroxide route. 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{sup }m, Z = 8, with a = 8.3940(2) ? at 295 K. The crystallographic formula is (Ni{sub 0.202(1)}Mn{sub 0.798(1)}){sub 8a}(Ni{sub 0.790(1)}Mn{sub 1.210(1)}){sub 16d}O{sub 4} where 8a and 16d stand for the tetrahedral and octahedral sites of the spinel structure, respectively. There is a significant inversion degree of the spinel structure, ? = 0.80. In fact, the variable parameter for the oxygen position, u = 0.2636(4), is far from that expected (u = 0.25) for normal spinels. From a bond-valence study, it seems that the valence distribution in NiMn{sub 2}O{sub 4} spinel is not as trivial as expected (Ni{sup 2+} and Mn{sup 3+}), but clearly the tetrahedral Mn ions are divalent whereas the octahedral Mn and Ni are slightly oxidized from the expected +3 and +2 values, respectively. The mixed valence observed at the octahedral sites provides the charge carriers that, by a hopping mechanism between Mn{sup 3+}/Mn{sup 4+} adjacent sites, leads to a significant conductivity, up to 0.85 S cm{sup ?1} at 800 C in air.

  7. Depth-dependent magnetism in epitaxial MnSb thin films: effects of surface passivation and cleaning

    SciTech Connect (OSTI)

    Aldous J. D.; Sanchez-Hanke C.; Burrows, C.W.; Maskery, I.; Brewer, M.S.; Hase, T.P.A.; Duffy, J.A.; Lees, M. Rs; Decoster, T.; Theis, W.; Quesada, A.; Schmid, A.K.; Bell, G.R.

    2012-03-15

    Depth-dependent magnetism in MnSb(0001) epitaxial films has been studied by combining experimental methods with different surface specificities: polarized neutron reflectivity, x-ray magnetic circular dichroism (XMCD), x-ray resonant magnetic scattering and spin-polarized low energy electron microscopy (SPLEEM). A native oxide {approx}4.5 nm thick covers air-exposed samples which increases the film's coercivity. HCl etching efficiently removes this oxide and in situ surface treatment of etched samples enables surface magnetic contrast to be observed in SPLEEM. A thin Sb capping layer prevents oxidation and preserves ferromagnetism throughout the MnSb film. The interpretation of Mn L{sub 3,2} edge XMCD data is discussed.

  8. Effect of Cu substitution on the magnetic and dielectric properties of La{sub 2}NiMnO{sub 6}

    SciTech Connect (OSTI)

    Biswal, A. K.; Ray, J.; Vishwakarma, P. N. E-mail: pnviisc@gmail.com; Babu, P. D.; Siruguri, V.

    2015-05-07

    In the continuation of our previous work [Biswal et al., J. Appl. Phys. 115, 194106 (2014)] of biphasic La{sub 2}NiMnO{sub 6} (LNM) prepared via sol-gel technique, here we are reporting the effect of Cu substitution at Ni site of LNM. The powder x-ray diffraction results of La{sub 2}Ni{sub 1?x}Cu{sub x}MnO{sub 6} (x?=?0, 0.05, 0.1) confirm the biphasic nature (Pbnm + R-3c) for all samples along with increasing R-3c phase with Cu content in the sample. The temperature variation of magnetization (M) plot shows sharp ferromagnetic transitions of R-3c phase at 285?K, 278?K, and 270?K (obtained from dM/dT plot) and that of Pbnm phase at 165?K, 145?K, and 145?K for x?=?0, 0.05, and 0.1, respectively. Weak antiferromagnetic type feature at 25?K (x?=?0), is getting pronounced with Cu content in the sample and is now seen at 32?K and 266?K (for x?=?0.05) and 32K and 257?K (for x?=?0.1). Fitting of Curie-Weiss law in the paramagnetic region of ?{sup ?1} vs T plot results slightly lower values of corresponding T{sub c}'s of R-3?c phase (277?K, 270?K, and 260?K), thus manifesting possibility of Griffiths like singularity. The onset temperature of Griffiths singularity occurs at 295?K (x?=?0) and 281?K (x?=?0.05 and 0.1), such that 295277?K in x?=?0, 281270?K in x?=?0.05, and 281260?K in x?=?0.1 sample is in Griffith's phase. Temperature dependent dielectric constant (?{sub r}) shows usual step-like transitions with corresponding relaxation peaks in the dielectric loss (D) part. Cu substitution in LNM makes the entire dielectric plot shifts towards lower temperature such that high temperature plateau of step transition becomes evident. The peaks in dielectric loss for all compositions are found to obey Arrhenius law with activation energies 237?meV, 207?meV, and 180?meV for x?=?0, 0.05, and 0.1, respectively.

  9. Itinerant Antiferromagnetism in FeMnP0.8Si0.2

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

    Sales, Brian C.; Susner, Michael A.; Conner, Benjamin S.; Yan, Jiaqiang Q.; May, Andrew F.

    2015-09-25

    Compounds based on the Fe2P structure have continued to attract interest because of the interplay between itinerant and localized magnetism in a noncentrosymmetric crystal structure, and because of the recent developments of these materials for magnetocaloric applications. We report the growth and characterization of millimeter-sized single crystals of FeMnP0.8Si0.2 with the Fe2P structure. Single-crystal x-ray diffraction, magnetization, resistivity, and Hall and heat capacity data are reported. The crystals exhibit itinerant antiferromagnetic order below 158 K with no hint of ferromagnetic behavior in the magnetization curves and with the spins ordered primarily in the ab plane. The room-temperature resistivity is closemore » to the Ioffe-Regel limit for a metal. Single-crystal x-ray diffraction indicates a strong preference for Mn to occupy the larger pyramidal 3g site. The cation site preference in the as-grown crystals and the antiferromagnetism were not changed after high-temperature anneals and a rapid quench to room temperature« less

  10. Electronic phase separation in lanthanum manganites: Evidence from {sup 55}Mn NMR

    SciTech Connect (OSTI)

    Allodi, G.; De Renzi, R.; Guidi, G.; Licci, F.; Pieper, M.W.

    1997-09-01

    {sup 55}Mn NMR experiments were carried out at 1.3{endash}4.2 K on six samples of lanthanum manganites, with a hole doping concentration ranging from the antiferromagnetic-insulator to the ferromagnetic-conductor region of the phase diagram. The dependence of the resonance frequencies on external fields is either as expected for ferromagnets (FM) or for antiferromagnets (AF). No indication of a canted phase could be detected. FM and AF resonances were found to coexist in all samples and are grouped in three broad bands, whose frequencies do not depend in first order on hole concentration. Strong evidence of interaction between AF and FM regions was provided by longitudinal relaxation experiments in several samples. An explanation of this behavior is offered in terms of intrinsic phase separation of the holes into FM microdomains. We determine the {sup 55}Mn hyperfine coupling to be isotropic in all cases, with A=6.2T/{mu}{sub B} for the on-site term in the AF domains. {copyright} {ital 1997} {ital The American Physical Society}

  11. Electronic and Magnetic Properties of Li1.5Mn0.5As Alloys in the Cu2Sb

    Office of Scientific and Technical Information (OSTI)

    Structure (Conference) | SciTech Connect Conference: Electronic and Magnetic Properties of Li1.5Mn0.5As Alloys in the Cu2Sb Structure Citation Details In-Document Search Title: Electronic and Magnetic Properties of Li1.5Mn0.5As Alloys in the Cu2Sb Structure × 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

  12. Suppression of the thermal hysteresis in magnetocaloric MnAs thin film by highly charged ion bombardment

    SciTech Connect (OSTI)

    Trassinelli, M. Marangolo, M.; Eddrief, M.; Etgens, V. H.; Gafton, V.; Hidki, S.; Lacaze, E.; Lamour, E.; Prigent, C.; Rozet, J.-P.; Steydli, S.; Zheng, Y.; Vernhet, D.

    2014-02-24

    We present the investigation on the modifications of structural and magnetic properties of MnAs thin film epitaxially grown on GaAs induced by slow highly charged ions bombardment under well-controlled conditions. The ion-induced defects facilitate the nucleation of one phase with respect to the other in the first-order magneto-structural MnAs transition, with a consequent suppression of thermal hysteresis without any significant perturbation on the other structural and magnetic properties. In particular, the irradiated film keeps the giant magnetocaloric effect at room temperature opening new perspective on magnetic refrigeration technology for everyday use.

  13. Thermochemical generation of hydrogen and oxygen from water. [NaMnO/sub 2/ and TiO/sub 2/

    DOE Patents [OSTI]

    Robinson, P.R.; Bamberger, C.E.

    1980-02-08

    A thermochemical cyclic process for the production of hydrogen exploits the reaction between sodium manganate (NaMnO/sub 2/) and titanium dioxide (TiO/sub 2/) to form sodium titanate (Na/sub 2/TiO/sub 3/), manganese (II) titanate (MnTiO/sub 3/) and oxygen. The titanate mixture is treated with sodium hydroxide, in the presence of steam, to form sodium titanate, sodium manganate (III), water and hydrogen. The sodium titanate-manganate (III) mixture is treated with water to form sodium manganate (III), titanium dioxide and sodium hydroxide. Sodium manganate (III) and titanium dioxide are recycled following dissolution of sodium hydroxide in water.

  14. Octonary resistance states in La0.7Sr0.3MnO3/BaTiO3/La0.7Sr0...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Octonary resistance states in La0.7Sr0.3MnO3BaTiO3La0.7Sr0.3MnO3 multiferroic tunnel junctions Citation Details In-Document Search This content will become ...

  15. I I I . Isotherm al Multicomponent Systems

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

    Nonequilibrium C ontrib ution to the Rate o f R eaction I I I . Isotherm al Multicomponent Systems t B. S h izg a l* Department o f C hem istry, Harvard U n iv e r sity Cambridge, M assachusetts and Lorentz I n s t it u t e fo r T h e o r e tic a l P h y sics L eid en , N etherlands and M. Karplus Department o f C hem istry, Harvard U n iv e r sity Cambridge, M assachusetts ----------------------------- L E G A L N O T I C E ----------------------------- T his report w as prepared as an accou n

  16. Rem&al Action Performed

    Office of Legacy Management (LM)

    Rem&al Action Performed at the B&T Metals Site in * Columbus, Ohio Department of Energy Office of Assistant Manager for Environmenta/ Management Oak Ridge Operations June 2007 Printed on recycled/recyclable paper. 1.41 2503.2 CERTIFICATION DOCKET FOR THE REMEDIAL ACTION PER-FORMED AT THE B&T METALS SITE IN COLUMBUS, OHIO JUNE 200 1 Prepared for United States Department of Energy Under Contract No. DACW45-98-D-0028 BY Bechtel National, Inc. Oak Ridge, Tennessee Bechtel Job No. 14501

  17. Microsoft Word - Final MR AL.doc

    Energy Savers [EERE]

    Department of Energy No. AL 2009-01 Acquisition Regulation Date: 10/06/2008 ACQUISITION LETTER This Acquisition Letter is issued under the authority of the DOE and NNSA Procurement Executives. Subject: Management Reserve and Contingency References: FAR Subpart 15.4 Contract Pricing FAR Part 31 Contract Cost Principles and Procedures FAR 31.205-7 Contingencies DEAR 915.404-4-70-2 Weighted Guidelines System DOE Order 413.3A Program and Project Management for the Acquisition of Capital Assets DOE

  18. CdSe/ZnSe quantum dot with a single Mn{sup 2+} ionA new system for a single spin manipulation

    SciTech Connect (OSTI)

    Smole?ski, T.

    2015-03-21

    We present a magneto-optical study of individual self-assembled CdSe/ZnSe quantum dots doped with single Mn{sup 2+} ions. Properties of the studied dots are analyzed analogously to more explored system of Mn-doped CdTe/ZnTe dots. Characteristic sixfold splitting of the neutral exciton emission line as well as its evolution in the magnetic field are described using a spin Hamiltonian model. Dynamics of both exciton recombination and Mn{sup 2+} spin relaxation are extracted from a series of time-resolved experiments. Presence of a single dopant is shown not to affect the average excitonic lifetime measured for a number of nonmagnetic and Mn-doped dots. On the other hand, non-resonant pumping is demonstrated to depolarize the Mn{sup 2+} spin in a quantum dot placed in external magnetic field. This effect is utilized to determine the ion spin relaxation time in the dark.

  19. Electronic and magnetic properties of double perovskite Dy{sub 2}MnCoO{sub 6} by first-principles calculation

    SciTech Connect (OSTI)

    Ganeshraj, C.; Santhosh, P. N.

    2014-05-07

    Using first-principles calculation, we investigate electronic and magnetic properties of Dy{sub 2}MnCoO{sub 6}. A detailed structural optimization has been done and found that the orthorhombic structure with Mn (Co) ions aligning along the longest axis type is the most stable structure. Within the generalized gradient approximation, the spin polarized calculations predict Dy{sub 2}MnCoO{sub 6} to be a half-metallic with ferromagnetic interaction between Mn and Co ions and antiferromagnetic interaction between Dy and Mn/Co ions. We also investigate the effect of Hubbard parameter (U) on the ground state magnetic structure. For all values of Hubbard U parameter the Co ions have nonzero magnetic moment; they do not lie in low-spin state, as in DyCoO{sub 3}.

  20. Electrochemically induced deposition method to prepare {gamma}-MnO{sub 2}/multi-walled carbon nanotube composites as electrode material in supercapacitors

    SciTech Connect (OSTI)

    Fan Zhen

    2008-08-04

    The {gamma}-MnO{sub 2}/multi-walled carbon nanotube ({gamma}-MnO{sub 2}/MWNT) composite has been prepared by electrochemically induced deposition method. The morphology and crystal structure of the composite were investigated by X-ray diffraction and scanning electron microscopy, respectively. The capacitive properties of the {gamma}-MnO{sub 2}/MWNT composite have been investigated by cyclic voltammetry (CV). A specific capacitance (based on {gamma}-MnO{sub 2}) as high as 579 F g{sup -1} is obtained at a scan rate of 10 mV s{sup -1} in 0.1 M Na{sub 2}SO{sub 4} aqueous solution. Additionally, the {gamma}-MnO{sub 2}/MWNT composite electrode shows excellent long-term cycle stability (only 2.4% decrease of the specific capacitance is observed after 500 CV cycles)

  1. Radiation-induced instability of MnS precipitates and its possible consequences on irradiation-induced stress corrosion cracking of austenitic stainless steels

    SciTech Connect (OSTI)

    Chung, H.M.; Sanecki, J.E.; Garner, F.A.

    1996-12-01

    Irradiation-assisted stress corrosion cracking (IASCC) is a significant materials issue for the light water reactor (LWR) industry and may also pose a problem for fusion power reactors that will use water as coolant. A new metallurgical process is proposed that involves the radiation-induced release into solution of minor impurity elements not usually thought to participate in IASCC. MnS-type precipitates, which contain most of the sulfur in stainless steels, are thought to be unstable under irradiation. First, Mn transmutes strongly to Fe in thermalized neutron spectra. Second, cascade-induced disordering and the inverse Kirkendall effect operating at the incoherent interfaces of MnS precipitates are thought to act as a pump to export Mn from the precipitate into the alloy matrix. Both of these processes will most likely allow sulfur, which is known to exert a deleterious influence on intergranular cracking, to re-enter the matrix. To test this hypothesis, compositions of MnS-type precipitates contained in several unirradiated and irradiated heats of Type 304, 316, and 348 stainless steels (SSs) were analyzed by Auger electron spectroscopy. Evidence is presented that shows a progressive compositional modification of MnS precipitates as exposure to neutrons increases in boiling water reactors. As the fluence increases, the Mn level in MnS decreases, whereas the Fe level increases. The S level also decreases relative to the combined level of Mn and Fe. MnS precipitates were also found to be a reservoir of other deleterious impurities such as F and O which could be also released due to radiation-induced instability of the precipitates.

  2. ALS X-Rays Shine a New Light on Catalysis

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

    ALS X-Rays Shine a New Light on Catalysis ALS X-Rays Shine a New Light on Catalysis Print Thursday, 21 May 2015 11:16 Electrocatalysts are responsible for expediting reactions in...

  3. Acquisition Letter No. AL 2014-02 | Department of Energy

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

    Acquisition Letter No. AL 2014-02 Acquisition Letter No. AL 2014-02 DATE: October 31, 2013 TO: Procurement DirectorsContracting Officers FROM: Director Contract and Financial...

  4. Surface Gas Sampling At Lightning Dock Area (Norman, Et Al.,...

    Open Energy Info (EERE)

    Surface Gas Sampling At Lightning Dock Area (Norman, Et Al., 2002) (Redirected from Water-Gas Samples At Lightning Dock Area (Norman, Et Al., 2002)) Jump to: navigation, search...

  5. Acquisition Letter No. AL 2013-01 | Department of Energy

    Office of Environmental Management (EM)

    1 Acquisition Letter No. AL 2013-01 PDF icon AL 2013-01.pdf More Documents & Publications Audit Report: DOE-IG-0890 Audit Report: DOE/IG-0928 Management Alert: IG-0864

  6. ALS Technique Gives Novel View of Lithium Battery Dendrite Growth

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

    ALS Technique Gives Novel View of Lithium Battery Dendrite Growth ALS Technique Gives Novel View of Lithium Battery Dendrite Growth Print Thursday, 24 April 2014 09:46 Lithium-ion...

  7. Microsoft Word - AL2005-08.doc | Department of Energy

    Office of Environmental Management (EM)

    8.doc Microsoft Word - AL2005-08.doc Microsoft Word - AL2005-08.doc More Documents & Publications OPAM Policy Acquisition Guides Attachment FY2011-28 OPAM Microsoft Word -...

  8. Microsoft Word - AL2008-05.doc | Department of Energy

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

    8-05.doc Microsoft Word - AL2008-05.doc PDF icon Microsoft Word - AL2008-05.doc More Documents & Publications Department of Energy OPAM Policy Acquisition Guides Microsoft PowerPoint - Executive Order13423rbl

  9. Microsoft Word - al95-06.doc | Department of Energy

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

    06.doc Microsoft Word - al95-06.doc PDF icon Microsoft Word - al95-06.doc More Documents & Publications ppl970-1.pdf Audit Report: IG-0589 Inspection Report: INS-O-02-01

  10. Data Transfer Considerations for ALS Scientists and Users

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

    Data Transfer Considerations for ALS Scientists and Users Print Introduction Working at the ALS generates huge amounts of data, and for many years this has caused users to have to...

  11. Six Berkeley Lab (Three ALS) Scientists Are 2012 APS Fellows

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

    Six Berkeley Lab (Three ALS) Scientists Are 2012 APS Fellows Six Berkeley Lab (Three ALS) Scientists Are 2012 APS Fellows Print Friday, 07 December 2012 00:00 This year's American...

  12. AL2003-01.pdf | Department of Energy

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

    3-01.pdf AL2003-01.pdf PDF icon AL2003-01.pdf More Documents & Publications FAL2003-01.pdf FAC2003-01.pdf Technical Interpretation, NSTI 2003-01

  13. AL2009-02.pdf | Department of Energy

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

    9-02.pdf AL2009-02.pdf PDF icon AL2009-02.pdf More Documents & Publications NNMCAB Board Minutes: May 2009 Santa Fe EMAB Reports and Recommendations - April 2009 MA-2009-000093Signed

  14. AL2009-06.pdf | Department of Energy

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

    6.pdf AL2009-06.pdf PDF icon AL2009-06.pdf More Documents & Publications The Next Regulatory Chapter for Commercial Vehicles SunShot Concentrating Solar Power Program SunShot Concentrating Solar Power Program

  15. Geothermal Literature Review (Wisian, Et Al., 2001) | Open Energy...

    Open Energy Info (EERE)

    navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Geothermal Literature Review (Wisian, Et Al., 2001) Exploration Activity Details Location Unspecified...

  16. Geographic Information System (Nash, Et Al., 2002) | Open Energy...

    Open Energy Info (EERE)

    search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Geographic Information System (Nash, Et Al., 2002) Exploration Activity Details Location Unspecified Exploration...

  17. Data Transfer Considerations for ALS Scientists and Users

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

    Data Transfer Considerations for ALS Scientists and Users Print Introduction Working at the ALS generates huge amounts of data, and for many years this has caused users to have to carry hard drives and USB drives between the ALS and their home institutions for acquisition and analysis of experimental data. To avoid the physical transport of data and to make real-time analysis possible, staff at the ALS, ESnet, and Berkeley Lab's IT Division have collaborated to implement several best practices

  18. Data Transfer Considerations for ALS Scientists and Users

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

    Data Transfer Considerations for ALS Scientists and Users Print Introduction Working at the ALS generates huge amounts of data, and for many years this has caused users to have to carry hard drives and USB drives between the ALS and their home institutions for acquisition and analysis of experimental data. To avoid the physical transport of data and to make real-time analysis possible, staff at the ALS, ESnet, and Berkeley Lab's IT Division have collaborated to implement several best practices

  19. Modeling-Computer Simulations (Combs, Et Al., 1999) | Open Energy...

    Open Energy Info (EERE)

    navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations (Combs, Et Al., 1999) Exploration Activity Details Location Unspecified...

  20. Acquisiton Letter No. AL 2016-04 | Department of Energy

    Energy Savers [EERE]

    4 Acquisiton Letter No. AL 2016-04 DATE: March 16, 2016 TO: Procurement Directors/Contracting Officers FROM: Acting Chief Contract and Financial Assistance Policy Division Office of Policy Office of Acquisition Management SUBJECT: Acquisition Letters Remaining in Effect SUMMARY: Acquisition letter 2016-04 has been issued. It lists ALs currently in effect and discontinued ALs, along with the reason why the AL is no longer in effect. This flash will be available online at the following website:

  1. ALD of Al2O3 for Highly Improved Performance in Li-Ion Batteries

    SciTech Connect (OSTI)

    Dillon, A.; Jung, Y. S.; Ban, C.; Riley, L.; Cavanagh, A.; Yan, Y.; George, S.; Lee, S. H.

    2012-01-01

    Significant advances in energy density, rate capability and safety will be required for the implementation of Li-ion batteries in next generation electric vehicles. We have demonstrated atomic layer deposition (ALD) as a promising method to enable superior cycling performance for a vast variety of battery electrodes. The electrodes range from already demonstrated commercial technologies (cycled under extreme conditions) to new materials that could eventually lead to batteries with higher energy densities. For example, an Al2O3 ALD coating with a thickness of ~ 8 A was able to stabilize the cycling of unexplored MoO3 nanoparticle anodes with a high volume expansion. The ALD coating enabled stable cycling at C/2 with a capacity of ~ 900 mAh/g. Furthermore, rate capability studies showed the ALD-coated electrode maintained a capacity of 600 mAh/g at 5C. For uncoated electrodes it was only possible to observe stable cycling at C/10. Also, we recently reported that a thin ALD Al2O3 coating with a thickness of ~5 A can enable natural graphite (NG) electrodes to exhibit remarkably durable cycling at 50 degrees C. The ALD-coated NG electrodes displayed a 98% capacity retention after 200 charge-discharge cycles. In contrast, bare NG showed a rapid decay. Additionally, Al2O3 ALD films with a thickness of 2 to 4 A have been shown to allow LiCoO2 to exhibit 89% capacity retention after 120 charge-discharge cycles performed up to 4.5 V vs Li/Li+. Bare LiCoO2 rapidly deteriorated in the first few cycles. The capacity fade is likely caused by oxidative decomposition of the electrolyte at higher potentials or perhaps cobalt dissolution. Interestingly, we have recently fabricated full cells of NG and LiCoO2 where we coated both electrodes, one or the other electrode as well as neither electrode. In creating these full cells, we observed some surprising results that lead us to obtain a greater understanding of the ALD coatings. We have also recently coated a binder free LiNi0.04Mn0.04Co02O2 electrode containing 5 wt% single-walled carbon nanotubes as the conductive additive and demonstrated both high rate capability as well as the ability to cycle the cathode to 5 V vrs. Li/Li+. Finally, we coated a Celgard (TM) separator and enabled stable cycling in a high dielectric electrolyte. These results will be presented in detail.

  2. MCrAlY bond coat with enhanced Yttrium layer

    DOE Patents [OSTI]

    Jablonski, Paul D; Hawk, Jeffrey A

    2015-04-21

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

  3. Microsoft Word - AL2005-11.doc | Department of Energy

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

    11.doc Microsoft Word - AL2005-11.doc PDF icon Microsoft Word - AL2005-11.doc More Documents & Publications Audit Report: OAS-L-13-08 Microsoft Word - AL2005-12.doc CHAPTER 7 FINANCIAL MANAGEMENT

  4. AL2004-01r2.pdf | Department of Energy

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

    4-01r2.pdf AL2004-01r2.pdf PDF icon AL2004-01r2.pdf More Documents & Publications Microsoft Word - AL2005-01.doc Microsoft Word - FAL2004-01.doc Preliminary Notice of Violation, Bechtel BWXT Idaho, LLC - EA-2004-01

  5. AL2008-06.pdf | Department of Energy

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

    6.pdf AL2008-06.pdf PDF icon AL 2008-06 More Documents & Publications Acquisitlon Letter No. AL 2008-06 General Services Administration Photovoltaics Project in Sacramento, California DOE Princeton Plasma Physics Laboratory Purchase Power Agreement Request for Proposal

  6. Microsoft Word - AL-ARRASafetyALREDO3 | Department of Energy

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

    ARRASafetyALREDO3 Microsoft Word - AL-ARRASafetyALREDO3 PDF icon Microsoft Word - AL-ARRASafetyALREDO3 More Documents & Publications Microsoft Word - AL-ARRASafetyALREDO3.doc DOE-STD-1083-2009 Activities of the DOE Sub Surface Working Group

  7. Microsoft Word - AL2002-03.doc | Department of Energy

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

    2-03.doc Microsoft Word - AL2002-03.doc PDF icon Microsoft Word - AL2002-03.doc More Documents & Publications Microsoft Word - AL2005-01.doc Microsoft Word - FAL2004-01.doc Microsoft Word - ARRAAttachment12v1.doc

  8. Microsoft Word - AL2005-16.doc | Department of Energy

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

    6.doc Microsoft Word - AL2005-16.doc PDF icon Microsoft Word - AL2005-16.doc More Documents & Publications Microsoft Word - AL2005-10.doc Policy Flash 2013-33 Department of Energy Order 206.2 Identity, Credential and Access Managment (ICAM) Audit Report: IG-0860

  9. Microsoft Word - AL2006-03.doc | Department of Energy

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

    3.doc Microsoft Word - AL2006-03.doc PDF icon Microsoft Word - AL2006-03.doc More Documents & Publications Microsoft Word - AL2006-02.doc Archived Financial Assistance Letters Financial Assistance Letters No. FAL 2006-04

  10. Microsoft Word - AL2006-09.doc | Department of Energy

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

    9.doc Microsoft Word - AL2006-09.doc PDF icon Microsoft Word - AL2006-09.doc More Documents & Publications Microsoft PowerPoint - Executive Order13423rbl Sample Contract Language for Construction Using Energy-Efficient Products AL2007-05.doc&#0;

  11. AL2006-04v2.pdf | Department of Energy

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

    4v2.pdf AL2006-04v2.pdf PDF icon AL2006-04v2.pdf More Documents & Publications Impacts of IPv6 on Infrastructure Control Systems Microsoft Word - AL2005-10.doc Department of Energy...

  12. Acquisition Letter No. AL 2013-10 | Department of Energy

    Energy Savers [EERE]

    10 Acquisition Letter No. AL 2013-10 PDF icon AL 2013-10.pdf PDF icon Consolidated Model H-Clause 06-17-13 PDF icon Signed Class Deviation 970.5244-1 More Documents & Publications Policy Flash 2016-11 Acquisition Letter No. AL 2016-01

  13. Acquisition Letters No. AL 2013-06 | Department of Energy

    Energy Savers [EERE]

    6 Acquisition Letters No. AL 2013-06 PDF icon AL 2013-06.pdf More Documents & Publications Financial Assistance Letter No. FAL 2013-04 Financial Assistance Letter No. FAL 2015-03 - Rev 2 - 08/03 Acquisition Letter No. AL 2015-04 - Rev. 2 - 08/25/2015

  14. Microsoft Word - al95-14.doc | Department of Energy

    Office of Environmental Management (EM)

    al95-14.doc Microsoft Word - al95-14.doc PDF icon Microsoft Word - al95-14.doc More Documents & Publications Cooperation with the New Independent States of the Former Soviet Union CDLB-1003.PDF&#0; 10 CFR 600.325 - Intellectual Property Provisions (GDLB-1003) Grant

  15. AL2008-07.pdf | Department of Energy

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

    8-07.pdf AL2008-07.pdf PDF icon AL2008-07.pdf More Documents & Publications Department of Energy Response to NNMCAB Recommendation 2008-07 2008-07 "Use of Risk-Based End States" AL2008-03

  16. Microsoft Word - AL2005-07.doc | Department of Energy

    Office of Environmental Management (EM)

    07.doc Microsoft Word - AL2005-07.doc PDF icon Microsoft Word - AL2005-07.doc More Documents & Publications Microsoft Word - AL2006-07.doc OPAM Policy Acquisition Guides Microsoft Word - 1_2011_CEG_Update_v2

  17. Synthesis, crystal structure, and vibrational spectroscopic and UV-visible studies of Cs{sub 2}MnP{sub 2}O{sub 7}

    SciTech Connect (OSTI)

    Kaoua, Saida; Krimi, Saida; Pechev, Stanislav; Gravereau, Pierre; Chaminade, Jean-Pierre; Couzi, Michel; El Jazouli, Abdelaziz

    2013-02-15

    A new member of the A{sub 2}MP{sub 2}O{sub 7} diphosphate family, Cs{sub 2}MnP{sub 2}O{sub 7}, has been synthesized and structurally characterized. The crystal structure was determined by single crystal X-Ray diffraction. Cs{sub 2}MnP{sub 2}O{sub 7} crystallizes in the orthorhombic system, space group Pnma ( Music-Sharp-Sign 62), with the unit cell parameters a=16.3398(3), b=5.3872(1), c=9.8872(2) A, Z=4 and V=870.33(3) A{sup 3}. The structure parameters were refined to a final R{sub 1}/wR{sub 2}=0.0194/0.0441 for 1650 observed reflections. The 2D framework of Cs{sub 2}MnP{sub 2}O{sub 7} structure consists of P{sub 2}O{sub 7} and MnO{sub 5} units. The corner-shared MnO{sub 5} and P{sub 2}O{sub 7} units are alternately arranged along the b axis to form [(MnO)P{sub 2}O{sub 7}]{sub {infinity}} chains. These chains are interconnected by an oxygen atom to form sheets parallel to the (b, c) plane. The cesium atoms are located between the sheets in 9- and 10-fold coordinated sites. The infrared and Raman vibrational spectra have been investigated. A factor group analysis leads to the determination of internal modes of (P{sub 2}O{sub 7}) groups. UV-visible spectrum consists of weak bands, between 340 and 700 nm, assigned to the forbidden d-d transitions of Mn{sup 2+} ion, and of a strong band around 250 nm, attributed to the O--Mn charge transfer. - Graphical abstract: Structure of Cs{sub 2}MnP{sub 2}O{sub 7}: The 2D structure of Cs{sub 2}MnP{sub 2}O{sub 7} is built from P{sub 2}O{sub 7} diphosphate groups and MnO{sub 5} square pyramids which share corners and form [(MnO)P{sub 2}O{sub 7}]{sub {infinity}} chains along b axis. These chains are interconnected by an oxygen atom to form wavy (MnP{sub 2}O{sub 7}){sup 2-} sheets parallel to the (b, c) plane. The cesium ions are located between these sheets in the inter-layers space, in zigzag positions. Highlights: Black-Right-Pointing-Pointer A new diphosphate, Cs{sub 2}MnP{sub 2}O{sub 7}, has been synthesized and structurally characterized. Black-Right-Pointing-Pointer The structure consists of a 2D framework built up from (MnP{sub 2}O{sub 7}) sheets. Black-Right-Pointing-Pointer The sheets consist of [(MnO)P{sub 2}O{sub 7}]{sub {infinity}} chains formed by P{sub 2}O{sub 7} units and MnO{sub 5} square pyramids. Black-Right-Pointing-Pointer A factor group analysis leads to the determination of internal modes of (P{sub 2}O{sub 7}) groups. Black-Right-Pointing-Pointer UV-visible spectrum consists bands assigned to d-d transitions of Mn{sup 2+} ion and to O--Mn CT.

  18. Controlled fabrication and tunable photoluminescence properties of Mn{sup 2+} doped grapheneZnO composite

    SciTech Connect (OSTI)

    Luan, Xinglong; Zhang, Yihe Tong, Wangshu; Shang, Jiwu; An, Qi; Huang, Hongwei

    2014-11-15

    Highlights: GrapheneZnO composites were synthesized by a mixed solvothermal method. ZnO quantum dots are distributed uniformly on the graphene sheets. A possible hypothesis is raised for the influence of graphene oxide on the nucleation of ZnO. Mn{sup 2+} doped grapheneZnO composites were fabricated and the emission spectra can be tuned by doping. - Abstract: GrapheneZnO composites (GZnO) with controlled morphology and photoluminescence property were synthesized by a mixed solvothermal method. Mixed solvent were composed by dimethyl sulfoxide and ethylene glycol. Fourier transform infrared spectroscopy, transmission electron microscopy and photoluminescence spectra were used to characterize GZnO. Graphene as a substrate can help the distribution and the dispersity of ZnO, and a possible model of the interaction between graphene oxide and ZnO particles is proposed. At the same time, graphene also reduce the size of ZnO particles to about 5 nm. Furthermore, Mn{sup 2+} ions dopes GZnO successfully by the mixed solvothermal synthesis and the doping of Mn{sup 2+} makes GZnO shift red from 465 nm to 548 nm and 554 nm in the emission spectrum. The changes of the emission spectrum by the adding of Mn{sup 2+} make GZnO have tunable photoluminescence spectrum which is desirable for practical applications.

  19. Excess Ni-doping induced enhanced room temperature magneto-functionality in Ni-Mn-Sn based shape memory alloy

    SciTech Connect (OSTI)

    Pramanick, S.; Giri, S.; Majumdar, S.; Chatterjee, S.

    2014-09-15

    Present work reports on the observation of large magnetoresistance (??30% at 80 kOe) and magnetocaloric effect (?12?Jkg{sup ?1}K{sup ?1} for 050 kOe) near room temperature (?290?K) on the Ni-excess ferromagnetic shape memory alloy Ni{sub 2.04}Mn{sub 1.4}Sn{sub 0.56}. The sample can be thought of being derived from the parent Ni{sub 2}Mn{sub 1.4}Sn{sub 0.6} alloy, where excess Ni was doped at the expense of Sn. Such Ni doping enhances the martensitic transition temperature and for the Ni{sub 2.04}Mn{sub 1.4}Sn{sub 0.56} it is found to be optimum (288?K). The doped alloy shows enhanced magneto-functional properties as well as reduced saturation magnetization as compared to the undoped counterpart at low temperature. A probable increment of antiferromagnetic correlation between Mn-atoms on Ni substitution can be accounted for the enhanced magneto-functional properties as well as reduction in saturation moment.

  20. Magnetic properties of MnSb inclusions formed in GaSb matrix directly during molecular beam epitaxial growth

    SciTech Connect (OSTI)

    Lawniczak-Jablonska, Krystyna; Wolska, Anna; Klepka, Marcin T.; Kret, Slawomir; Kurowska, Boguslawa; Kowalski, Bogdan J.; Twardowski, Andrzej; Wasik, Dariusz; Kwiatkowski, Adam; Sadowski, Janusz

    2011-04-01

    Despite of intensive search for the proper semiconductor base materials for spintronic devices working at room temperature no appropriate material based on ferromagnetic semiconductors has been found so far. We demonstrate that the phase segregated system with MnSb hexagonal inclusions inside the GaSb matrix, formed directly during the molecular beam epitaxial growth reveals the ferromagnetic properties at room temperature and is a good candidate for exploitation in spintronics. Furthermore, the MnSb inclusions with only one crystalline structure were identified in this GaMn:MnSb granular material. The SQUID magnetometry confirmed that this material exhibits ferromagnetic like behavior starting from helium up to room temperature. Moreover, the magnetic anisotropy was found which was present also at room temperature, and it was proved that by choosing a proper substrate it is possible to control the direction of easy axis of inclusions' magnetization moment between in-plane and out-of-plane; the latter is important in view of potential applications in spintronic devices.

  1. Unusual magnetic hysteresis and the weakened transition behavior induced by Sn substitution in Mn{sub 3}SbN

    SciTech Connect (OSTI)

    Sun, Ying, E-mail: sunying@buaa.edu.cn [Center for Condensed Matter and Materials Physics, Department of Physics, Beihang University, Beijing 100191 (China); International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science, Tsukuba, Ibaraki 305-0044 (Japan); Guo, Yanfeng; Li, Jun; Wang, Xia [Superconducting Properties Unit, National Institute for Materials Science, Tsukuba, Ibaraki 305-0044 (Japan); Tsujimoto, Yoshihiro [Materials Processing Unit, National Institute for Materials Science, Tsukuba, Ibaraki 305-0047 (Japan); Wang, Cong [Center for Condensed Matter and Materials Physics, Department of Physics, Beihang University, Beijing 100191 (China); Feng, Hai L.; Sathish, Clastin I.; Yamaura, Kazunari, E-mail: yamaura.kazunari@nims.go.jp [Superconducting Properties Unit, National Institute for Materials Science, Tsukuba, Ibaraki 305-0044 (Japan); Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Hokkaido 060-0810 (Japan); Matsushita, Yoshitaka [Analysis Station, National Institute for Materials Science, Tsukuba, Ibaraki 305-0047 (Japan)

    2014-01-28

    Substitution of Sb with Sn was achieved in ferrimagnetic antiperovskite Mn{sub 3}SbN. The experimental results indicate that with an increase in Sn concentration, the magnetization continuously decreases and the crystal structure of Mn{sub 3}Sb{sub 1-x}Sn{sub x}N changes from tetragonal to cubic phase at around x of 0.8. In the doping series, step-like anomaly in the isothermal magnetization was found and this behavior was highlighted at x?=?0.4. The anomaly could be attributed to the magnetic frustration, resulting from competition between the multiple spin configurations in the antiperovskite lattice. Meantime, H{sub c} of 18 kOe was observed at x?=?0.3, which is probably the highest among those of manganese antiperovskite materials reported so far. With increasing Sn content, the abrupt change of resistivity and the sharp peak of heat capacity in Mn{sub 3}SbN were gradually weakened. The crystal structure refinements indicate the weakened change at the magnetic transition is close related to the change of c/a ratio variation from tetragonal to cubic with Sn content. The results derived from this study indicate that the behavior of Mn{sub 3}Sb{sub 1-x}Sn{sub x}N could potentially enhance its scientific and technical applications, such as spin torque transfer and hard magnets.

  2. Ab initio molecular dynamics of Al irradiation-induced processes during Al{sub 2}O{sub 3} growth

    SciTech Connect (OSTI)

    Music, Denis; Nahif, Farwah; Friederichsen, Niklas; Schneider, Jochen M.; Sarakinos, Kostas

    2011-03-14

    Al bombardment induced structural changes in {alpha}-Al{sub 2}O{sub 3} (R-3c) and {gamma}-Al{sub 2}O{sub 3} (Fd-3m) were studied using ab initio molecular dynamics. Diffusion and irradiation damage occur for both polymorphs in the kinetic energy range from 3.5 to 40 eV. However, for {gamma}-Al{sub 2}O{sub 3}(001) subplantation of impinging Al causes significantly larger irradiation damage and hence larger mobility as compared to {alpha}-Al{sub 2}O{sub 3}. Consequently, fast diffusion along {gamma}-Al{sub 2}O{sub 3}(001) gives rise to preferential {alpha}-Al{sub 2}O{sub 3}(0001) growth, which is consistent with published structure evolution experiments.

  3. Electronic transport through Al/InN nanowire/Al junctions

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

    Lu, Tzu -Ming; Wang, George T.; Pan, Wei; Zhao, S.; Mi, Z.

    2016-02-10

    We report non-linear electronic transport measurement of Al/Si-doped n-type InN nanowire/Al junctions performed at T = 0.3 K, below the superconducting transition temperature of the Al electrodes. The proximity effect is observed in these devices through a strong dip in resistance at zero bias. In addition to the resistance dip at zero bias, several resistance peaks can be identified at bias voltages above the superconducting gap of the electrodes, while no resistance dip is observed at the superconducting gap. The resistance peaks disappear as the Al electrodes turn normal beyond the critical magnetic field except one which remains visible atmore » fields several times higher than critical magnetic field. An unexpected non-monotonic magnetic field dependence of the peak position is observed. As a result, we discuss the physical origin of these observations and propose that the resistance peaks could be the McMillan-Rowell oscillations arising from different closed paths localized near different regions of the junctions.« less

  4. Magnetization anomaly of Nb3Al strands and instability of Nb3Al Rutherford cables

    SciTech Connect (OSTI)

    Yamada, Ryuji; /Fermilab; Kikuchi, Akihiro; /Tsukuba Magnet Lab; Wake, Masayoshi; /KEK, Tsukuba

    2006-08-01

    Using a Cu stabilized Nb{sub 3}Al strand with Nb matrix, a 30 meter long Nb{sub 3}Al Rutherford cable was made by a collaboration of Fermilab and NIMS. Recently the strand and cable were tested. In both cases instability was observed at around 1.5 Tesla. The magnetization of this Nb{sub 3}Al strand was measured first using a balanced coil magnetometer at 4.2 K. Strands showed an anomalously large magnetization behavior around at 1.6 T, which is much higher than the usual B{sub c2} {approx} 0.5 Tesla (4.2 K) of Nb matrix. This result is compared with the magnetization data of short strand samples using a SQUID magnetometer, in which a flux-jump signal was observed at 0.5 Tesla, but not at higher field. As a possible explanation for this magnetization anomaly, the interfilament coupling through the thin Nb films in the strands is suggested. The instability problem observed in low field tests of the Nb{sub 3}Al Rutherford cables is attributed to this effect.

  5. Summary Slides of ALS Science Highlights

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

    Summary Slides of ALS Science Highlights Print No. Slide Beamline Full Web Highlight ALSNews Volume 327 Aerosol Oxidation Speeds Up in Smoggy Air 9.0.2 02.24.2016 Vol. 370 326 Porous Framework Electrocatalysts Are Key to CO2... 7.3.3, 10.3.2 02.24.2016 Vol. 370 325 Phonon Polariton Behavior in 2D Materials 5.4.1 01.27.2016 Vol. 369 324 Manganese Reduction-Oxidation Drives Plant Debris... 1.4.3, 9.0.2, 10.3.2 02.24.2016 Vol. 370 323 A New Pathway for Radionuclide Uptake 5.0.1, 5.0.2 01.27.2016

  6. Summary Slides of ALS Science Highlights

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

    Summary Slides of ALS Science Highlights Print No. Slide Beamline Full Web Highlight ALSNews Volume 327 Aerosol Oxidation Speeds Up in Smoggy Air 9.0.2 02.24.2016 Vol. 370 326 Porous Framework Electrocatalysts Are Key to CO2... 7.3.3, 10.3.2 02.24.2016 Vol. 370 325 Phonon Polariton Behavior in 2D Materials 5.4.1 01.27.2016 Vol. 369 324 Manganese Reduction-Oxidation Drives Plant Debris... 1.4.3, 9.0.2, 10.3.2 02.24.2016 Vol. 370 323 A New Pathway for Radionuclide Uptake 5.0.1, 5.0.2 01.27.2016

  7. Strain-induced dimensionality crossover of precursor modulations in Ni{sub 2}MnGa

    SciTech Connect (OSTI)

    Nie, Zhihua E-mail: ydwang@neu.edu.cn; Wang, Yandong E-mail: ydwang@neu.edu.cn; Shang, Shunli; Wang, Yi; Liu, Zi-Kui; Zeng, Qiaoshi; Ren, Yang; Liu, Dongmei; Yang, Wenge

    2015-01-12

    Precursor modulations often occur in functional materials like magnetic shape memory alloys, ferroelectrics, and superconductors. In this letter, we have revealed the underlying mechanism of the precursor modulations in ferromagnetic shape memory alloys Ni{sub 2}MnGa by combining synchrotron-based x-ray diffraction experiments and first-principles phonon calculations. We discovered the precursor modulations along [011] direction can be eliminated with [001] uniaxial loading, while the precursor modulations or premartensite can be totally suppressed by hydrostatic pressure condition. The TA{sub 2} phonon anomaly is sensitive to stress induced lattice strain, and the entire TA{sub 2} branch is stabilized along the directions where precursor modulations are eliminated by external stress. Our discovery bridges precursor modulations and phonon anomalies, and sheds light on the microscopic mechanism of the two-step superelasticity in precursor martensite.

  8. Magnetic-field-induced transformation in FeMnGa alloys

    SciTech Connect (OSTI)

    Zhu, W.; Liu, E. K.; Feng, L.; Tang, X. D.; Chen, J. L.; Wu, G. H.; Liu, H. Y.; Meng, F. B.; Luo, H. Z.

    2009-11-30

    A kind of ferromagnetic shape memory alloy with off-stoichiometric composition of Heusler alloy Fe{sub 2}MnGa has been synthesized. By optimizing composition, the martensitic transformation has been modified to occur at about 163 K accompanying spontaneous magnetization, which enables a magnetic field-induced structural transition from a paramagnetic parent phase to a ferromagnetic martensite with high magnetization of 93.8 emu/g. The material performs a quite large lattice distortion through the transformation, (c-a)/c=33.5%, causing a shape memory strain upto 3.6%. Such large lattice distortions strongly influence the electron structures, and thus some special physical behavior related to the transport and conductive properties is investigated.

  9. NaNi sub 3 Mn sub 2 alloy as a tritium storage material

    SciTech Connect (OSTI)

    Ide, T.; Okuno, K.; Konishi, S.; Sakai, F.; Fukui, H.; Enoeda, M.; Naruse, Y.; Anderson, J.L.; Bartlit, J.R.; Los Alamos National Lab., NM )

    1989-01-01

    An all metal apparatus has been constructed and installed in the main cell of the Tritium System Assembly (TSTA) at Los Alamos National Laboratory, as a separate experiment, to handle about 2600 Ci of tritium for study of metal tritides of potential application for storing tritium in fusion fuel processing. The apparatus is similar to that used for protium/deuterium gas but some modifications were made to assure safe handling of tritium. The pressure-composition isotherms for the LaNi{sub 3}Mn{sub 2}-protium (H), deuterium (D) and tritium (T) system were measured to study isotopic effects in the temperature range of 60 {degree}C to 250 {degree}C, the pressure range below 120 kPa. 2 refs., 10 figs.

  10. High spin polarization in CoFeMnGe equiatomic quaternary Heusler alloy

    SciTech Connect (OSTI)

    Bainsla, Lakhan; Suresh, K. G.; Nigam, A. K.; Manivel Raja, M.; Varaprasad, B. S. D. Ch. S.; Takahashi, Y. K.; Hono, K.

    2014-11-28

    We report the structure, magnetic property, and spin polarization of CoFeMnGe equiatomic quaternary Heusler alloy. The alloy was found to crystallize in the cubic Heusler structure (prototype LiMgPdSn) with considerable amount of DO{sub 3} disorder. Thermal analysis result indicated the Curie temperature is about 750 K without any other phase transformation up to melting temperature. The magnetization value was close to that predicted by the Slater-Pauling curve. Current spin polarization of P = 0.70 ± 0.01 was deduced using point contact andreev reflection measurements. The temperature dependence of electrical resistivity has been fitted in the temperature range of 5–300 K in order to check for the half metallic behavior. Considering the high spin polarization and Curie temperature, this material appears to be promising for spintronic applications.

  11. Structural controlled magnetic anisotropy in Heusler L1{sub 0}-MnGa epitaxial thin films

    SciTech Connect (OSTI)

    Wang Kangkang; Lu Erdong; Smith, Arthur R.; Knepper, Jacob W.; Yang Fengyuan

    2011-04-18

    Ferromagnetic L1{sub 0}-MnGa thin films have been epitaxially grown on GaN, sapphire, and MgO substrates using molecular beam epitaxy. Using diffraction techniques, the epitaxial relationships are determined. It is found that the crystalline orientation of the films differ due to the influence of the substrate. By comparing the magnetic anisotropy to the structural properties, a clear correlation could be established indicating that the in-plane and out-of-plane anisotropy is directly determined by the crystal orientation of the film and could be controlled via selection of the substrates. This result could be helpful in tailoring magnetic anisotropy in thin films for spintronic applications.

  12. Electric field-induced magnetic switching in Mn:ZnO film

    SciTech Connect (OSTI)

    Ren, S. X.; Sun, G. W.; Zhao, J.; Dong, J. Y.; Zhao, X.; Chen, W.; Wei, Y.; Ma, Z. C.

    2014-06-09

    A large magnetic modulation, accompanied by stable bipolar resistive switching (RS) behavior, was observed in a Mn:ZnO film by applying a reversible electric field. A significant enhancement of the ferromagnetism of the film, to about five times larger than that in the initial (as-grown) state (IS), was obtained by switching the film into the low resistance state. X-ray photoelectron spectroscopy demonstrated the existence of abundant oxygen vacancies in the IS of the film. We suggest that this electric field-induced magnetic switching effect originates with the migration and redistribution of oxygen vacancies during RS. Our work indicates that electric switching is an effective and simple method to increase the ferromagnetism of diluted magnetic oxide films. This provides a promising direction for research in spintronic devices.

  13. High temperature dielectric relaxation anomaly of Y? and Mn? doped barium strontium titanate ceramics

    SciTech Connect (OSTI)

    Yan, Shiguang; Mao, Chaoliang E-mail: xldong@mail.sic.ac.cn; Wang, Genshui; Yao, Chunhua; Cao, Fei; Dong, Xianlin E-mail: xldong@mail.sic.ac.cn

    2014-10-14

    Relaxation like dielectric anomaly is observed in Y? and Mn? doped barium strontium titanate ceramics when the temperature is over 450 K. Apart from the conventional dielectric relaxation analysis method with Debye or modified Debye equations, which is hard to give exact temperature dependence of the relaxation process, dielectric response in the form of complex impedance, assisted with Cole-Cole impedance model corrected equivalent circuits, is adopted to solve this problem and chase the polarization mechanism in this paper. Through this method, an excellent description to temperature dependence of the dielectric relaxation anomaly and its dominated factors are achieved. Further analysis reveals that the exponential decay of the Cole distribution parameter n with temperature is confirmed to be induced by the microscopic lattice distortion due to ions doping and the interaction between the defects. At last, a clear sight to polarization mechanism containing both the intrinsic dipolar polarization and extrinsic distributed oxygen vacancies hopping response under different temperature is obtained.

  14. The manifestation of spin-phonon coupling in CaMnO{sub 3}

    SciTech Connect (OSTI)

    Goian, V. Kamba, S.; Borodavka, F.; Nuzhnyy, D.; Savinov, M.; Belik, A. A.

    2015-04-28

    Recently predicted presence of spin-phonon coupling in the CaMnO{sub 3} is experimentally confirmed in infrared (IR), Raman and time-domain THz spectra. Most of phonon frequencies seen below 350?cm{sup ?1} exhibit significant shifts on cooling below antiferromagnetic phase transition at T{sub N}???120?K. Moreover, several new modes activate in the IR and Raman spectra on cooling below T{sub N}. Sum of phonon contributions to static permittivity exhibits small but reliable anomaly at T{sub N}. On the other hand, the spin-phonon coupling is not manifested in temperature dependence of radio-frequency permittivity, because intrinsic permittivity is screened by extrinsic contribution from conductivity, which enhances the permittivity to giant values.

  15. Unraveling the voltage fade mechanism in layer Li-Mn-rich electrode: formation of the tetrahedral cations for spinel conversion

    SciTech Connect (OSTI)

    Mohanty, Debasish; Li, Jianlin; Abraham, Daniel P; Huq, Ashfia; Payzant, E Andrew; Wood III, David L; Daniel, Claus

    2014-01-01

    Discovery of high-voltage layered lithium-and manganese-rich (LMR) composite oxide electrode has dramatically enhanced the energy density of current Li-ion energy storage systems. However, practical usage of these materials is currently not viable because of their inability to maintain a consistent voltage profile (voltage fading) during subsequent charge-discharge cycles. This report rationalizes the cause of this voltage fade by providing the evidence of layer to spinel-like (LSL) structural evolution pathways in the host Li1.2Mn0.55Ni0.15Co0.1O2 LMR composite oxide. By employing neutron powder diffraction, and temperature dependent magnetic susceptibility, we show that LSL structural rearrangement in LMR oxide occurs through a tetrahedral cation intermediate via: i) diffusion of lithium atoms from octahedral to tetrahedral sites of the lithium layer [(LiLioct LiLitet] which is followed by the dispersal of the lithium ions from the adjacent octahedral site of the metal layer to the tetrahedral sites of lithium layer [LiTM oct LiLitet]; and ii) migration of Mn from the octahedral sites of the transition metal layer to the permanent octahedral site of lithium layer via tetrahedral site of lithium layer [MnTMoct MnLitet MnLioct)]. The findings opens the door to the potential routes to mitigate this atomic restructuring in the high-voltage LMR composite oxide cathodes by manipulating the composition/structure for practical use in high-energy-density lithium-ion batteries.

  16. Synthesis and characterization of R{sub 2}MnTiO{sub 7} (R = Y and Er) pyrochlores oxides

    SciTech Connect (OSTI)

    Martnez-Coronado, R.; Alonso, J.A.; Fernndez, M.T.

    2013-09-01

    Graphical abstract: - Abstract: New pyrochlore-like phases of composition R{sub 2}MnTiO{sub 7} (R = Er and Y) have been synthesized by a soft-chemistry procedure involving citrates of the different metal ions followed by thermal treatments at moderate temperatures (850 C for 12 h in air). A characterization by X-ray diffraction and neutron powder diffraction (NPD) has been carried out in order to determine the crystal structure features: these phyrochlores are cubic, space group Fd-3m, defining an intrinsically frustrated three-dimensional system. The Rietveld-refinement from NPD data at room temperature evidences an antisite cation disorder (distribution of Mn between A and B positions) that is accompanied by an increment of the oxygen-vacancy concentration due to the reduction of Mn{sup 4+} at the B position to Mn{sup 2+} at the A position. Thermogravimetric analysis (TGA) was useful to evaluate the stability of these oxides in reducing conditions up to 500 C. Magnetic susceptibility measurements indicate a ferromagnetic behavior, due to the random distribution of Mn{sup 4+} ions in the octahedral sublattice. At lower temperatures there is a polarization of the R{sup +3} magnetic moments, which also participate in the magnetic structure. Aiming to evaluate these materials as possible electrodes for solid oxide fuel cells (SOFC) we determined that the thermal expansion coefficients between 100 and 900 C perfectly match with those of the usual electrolytes; however, these pyrochlore oxides display a semiconductor-like behavior with poor conductivity values, e.g. 6 10{sup ?3} cm{sup ?1} at 850 C for Er, which would prevent its use as MIEC (mixed ionic-electronic conductors) oxides in SOFC devices.

  17. DOE - Office of Legacy Management -- Southern Research Institute - AL 03

    Office of Legacy Management (LM)

    Southern Research Institute - AL 03 FUSRAP Considered Sites Site: SOUTHERN RESEARCH INSTITUTE (AL.03) Eliminated from consideration under FUSRAP Designated Name: Not Designated Alternate Name: None Location: 917 South 20th Street , Birmingham , Alabama AL.03-1 AL.03-2 Evaluation Year: 1993 AL.03-3 Site Operations: Licensed for the period 11/10/55 - 6/1/58. Basic license and three amendments for possession and title to up to 140# of refined source material for research on properties of

  18. The role of the (111) texture on the exchange bias and interlayer coupling effects observed in sputtered NiFe/IrMn/Co trilayers

    SciTech Connect (OSTI)

    Castro, I. L.; Nascimento, V. P.; Passamani, E. C.; Takeuchi, A. Y.; Larica, C.; Tafur, M.; Pelegrini, F.

    2013-05-28

    Magnetic properties of sputtered NiFe/IrMn/Co trilayers grown on different seed layers (Cu or Ta) deposited on Si (100) substrates were investigated by magnetometry and ferromagnetic resonance measurements. Exchange bias effect and magnetic spring behavior have been studied by changing the IrMn thickness. As shown by X-ray diffraction, Ta and Cu seed layers provoke different degrees of (111) fcc-texture that directly affect the exchange bias and indirectly modify the exchange spring coupling behavior. Increasing the IrMn thickness, it was observed that the coupling angle between the Co and NiFe ferromagnetic layers increases for the Cu seed system, but it reduces for the Ta case. The results were explained considering (i) different anisotropies of the Co and IrMn layers induced by the different degree of the (111) texture and (ii) the distinct exchange bias set at the NiFe/IrMn and IrMn/Co interfaces in both systems. The NiFe and Co interlayer coupling angle is strongly correlated with both exchange bias and exchange magnetic spring phenomena. It was also shown that the highest exchange bias field occurs when an unstressed L1{sub 2} IrMn structure is stabilized.

  19. First principles treatment of structural, optical, and thermoelectric properties of Li{sub 7}MnN{sub 4} as electrode for a Li secondary battery

    SciTech Connect (OSTI)

    Khan, Wilayat; Reshak, A.H.

    2015-01-15

    The electronic structure, electronic charge density and linear optical properties of the metallic Li{sub 7}MnN{sub 4} compound, having cubic symmetry, are calculated using the full potential linearized augmented plane wave (FP-LAPW) method. The calculated band structure and density of states using the local density, generalized gradient and EngelVosko approximations, depict the metallic nature of the cubic Li{sub 7}MnN{sub 4} compound. The bands crossing the Fermi level in the calculated band structure are mainly from the Mn-d states with small support of N-p states. In addition, the Mn-d states at the Fermi level enhance the density of states, which is very useful for the electronic transport properties. The valence electronic charge density depicts strong covalent bond between Mn and two N atoms and polar covalent bond between Mn and Li atoms. The frequency dependent linear optical properties like real and imaginary part of the dielectric function, optical conductivity, reflectivity and energy loss function are calculated on the basis of the computed band structure. Both intra-band and inter-band transitions contribute to the calculated optical parameters. Using the BoltzTraP code, the thermoelectric properties like electrical and thermal conductivity, Seebeck coefficient, power coefficient and heat capacity of the Li{sub 7}MnN{sub 4} are also calculated as a function of temperature and studied.

  20. Effect of CoFe insertion in Co{sub 2}MnSi/CoFe/n-GaAs junctions on spin injection properties

    SciTech Connect (OSTI)

    Ebina, Yuya; Akiho, Takafumi; Liu, Hong-xi; Yamamoto, Masafumi; Uemura, Tetsuya

    2014-04-28

    The CoFe thickness (t{sub CoFe}) dependence of spin injection efficiency was investigated for Co{sub 2}MnSi/CoFe/n-GaAs junctions. The ?V{sub NL}/I value, which is a measure of spin injection efficiency, strongly depended on t{sub CoFe}, where ?V{sub NL} is the amplitude of a nonlocal spin-valve signal, and I is an injection current. Importantly, the maximum value of ?V{sub NL}/I for a Co{sub 2}MnSi/CoFe/n-GaAs junction was one order of magnitude higher than that for a CoFe/n-GaAs junction, indicating that a Co{sub 2}MnSi electrode works as a highly polarized spin source. No clear spin signal, on the other hand, was observed for a Co{sub 2}MnSi/n-GaAs junction due to diffusion of Mn atoms into the GaAs channel. Secondary ion mass spectrometry analysis indicated that the CoFe insertion effectively suppressed the diffusion of Mn into GaAs, resulting in improved spin injection properties compared with those for a Co{sub 2}MnSi/n-GaAs junction.