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We encourage you to perform a real-time search of NLEBeta
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1

High-harmonic XUV source for time- and angle-resolved photoemission spectroscopy  

SciTech Connect (OSTI)

We present a laser-based apparatus for visible pump/XUV probe time- and angle-resolved photoemission spectroscopy (TRARPES) utilizing high-harmonic generation from a noble gas. Femtosecond temporal resolution for each selected harmonic is achieved by using a time-delay-compensated monochromator (TCM). The source has been used to obtain photoemission spectra from insulators (UO{sub 2}) and ultrafast pump/probe processes in semiconductors (GaAs).

Dakovski, Georgi L [Los Alamos National Laboratory; Li, Yinwan [Los Alamos National Laboratory; Durakiewicz, Tomasz [Los Alamos National Laboratory; Rodriguez, George [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

2

Angle-resolved photoemission spectroscopy study of HgBa[subscript 2]CuO[subscript 4+?  

E-Print Network [OSTI]

HgBa[subscript 2]CuO[subscript 4+?]. (Hg1201) has been shown to be a model cuprate for scattering, optical, and transport experiments, but angle-resolved photoemission spectroscopy (ARPES) data are still lacking owing to ...

Chan, M. K.

3

Electronic Structure of the Topological Insulator Bi[subscript 2]Se[subscript 3] Using Angle-Resolved Photoemission Spectroscopy: Evidence for a Nearly Full Surface Spin Polarization  

E-Print Network [OSTI]

We performed high-resolution spin- and angle-resolved photoemission spectroscopy studies of the electronic structure and the spin texture on the surface of Bi[subscript 2]Se[subscript 3], a model TI. By tuning the photon ...

Pan, Z.-H.

4

Tunable vacuum ultraviolet laser based spectrometer for angle resolved photoemission spectroscopy  

SciTech Connect (OSTI)

We have developed an angle-resolved photoemission spectrometer with tunable vacuum ultraviolet laser as a photon source. The photon source is based on the fourth harmonic generation of a near IR beam from a Ti:sapphire laser pumped by a CW green laser and tunable between 5.3 eV and 7 eV. The most important part of the set-up is a compact, vacuum enclosed fourth harmonic generator based on potassium beryllium fluoroborate crystals, grown hydrothermally in the US. This source can deliver a photon flux of over 10{sup 14} photon/s. We demonstrate that this energy range is sufficient to measure the k{sub z} dispersion in an iron arsenic high temperature superconductor, which was previously only possible at synchrotron facilities.

Jiang, Rui; Mou, Daixiang; Wu, Yun; Huang, Lunan; Kaminski, Adam [Division of Materials Science and Engineering, Ames Laboratory, Ames, Iowa 50011 (United States) [Division of Materials Science and Engineering, Ames Laboratory, Ames, Iowa 50011 (United States); Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011 (United States); McMillen, Colin D.; Kolis, Joseph [Department of Chemistry, Clemson University, Clemson, South Carolina 29634 (United States)] [Department of Chemistry, Clemson University, Clemson, South Carolina 29634 (United States); Giesber, Henry G.; Egan, John J. [Advanced Photonic Crystals LLC, Fort Mill, South Carolina 29708 (United States)] [Advanced Photonic Crystals LLC, Fort Mill, South Carolina 29708 (United States)

2014-03-15T23:59:59.000Z

5

Intrinsic ultrathin topological insulators grown via molecular beam epitaxy characterized by in-situ angle resolved photoemission spectroscopy  

SciTech Connect (OSTI)

We demonstrate the capability of growing high quality ultrathin (10 or fewer quintuple layers) films of the topological insulators Bi{sub 2}Se{sub 3} and Bi{sub 2}Te{sub 3} using molecular beam epitaxy. Unlike previous growth techniques, which often pin the Fermi energy in the conduction band for ultrathin samples, our samples remain intrinsic bulk insulators. We characterize these films using in-situ angle resolved photoemission spectroscopy, which is a direct probe of bandstructure, and ex-situ atomic force microscopy. We find that the conduction band lies above the Fermi energy, indicating bulk insulating behavior with only the surface states crossing the Fermi energy. The use of a thermal cracker allows for more stoichiometric flux rates during growth, while still creating intrinsically doped films, paving the way for future improvements in growth of topological insulators.

Lee, J. J.; Vishik, I. M.; Ma, Y.; Shen, Z. X. [Department of Applied Physics, Stanford University, Stanford, California 94305 (United States); Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Geballe Laboratory for Advanced Materials, Department of Applied Physics, Stanford University, Stanford, California 94305 (United States); Schmitt, F. T.; Moore, R. G. [Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Geballe Laboratory for Advanced Materials, Department of Applied Physics, Stanford University, Stanford, California 94305 (United States)

2012-07-02T23:59:59.000Z

6

Electronic Structure of the Topological Insulator Bi2Se3 Using Angle-Resolved Photoemission Spectroscopy: Evidence for a Nearly Full Surface Spin Polarization  

SciTech Connect (OSTI)

We performed high-resolution spin- and angle-resolved photoemission spectroscopy studies of the electronic structure and the spin texture on the surface of Bi{sub 2}Se{sub 3}, a model TI. By tuning the photon energy, we found that the topological surface state is well separated from the bulk states in the vicinity of k{sub z} = Z plane of the bulk Brillouin zone. The spin-resolved measurements in that region indicate a very high degree of spin polarization of the surface state, {approx}0.75, much higher than previously reported. Our results demonstrate that the topological surface state on Bi{sub 2}Se{sub 3} is highly spin polarized and that the dominant factors limiting the polarization are mainly extrinsic.

Pan, Z.H.; Vescovo, E.; Fedorov, A.V.; Gardner, D.; Lee, Y.S.; Chu, S.; Gu, G.D.; Valla, T.

2011-06-22T23:59:59.000Z

7

E-Print Network 3.0 - angle-resolved photoemission extended Sample...  

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

photoemission evidence for a Gd(0001) surface state Dongqi Lia, C.W. Hutchings... April 1991. Available online 31 July 2002. Abstract From angle resolved photoemission we have...

8

Doping Dependence of the $(\\pi,\\pi)$ Shadow Band in La-Based Cuprates Studied by Angle-Resolved Photoemission Spectroscopy  

SciTech Connect (OSTI)

The ({pi},{pi}) shadow band (SB) in La-based cuprate family (La214) was studied by angle-resolved photoemission spectroscopy (ARPES) over a wide doping range from x = 0.01 to x = 0.25. Unlike the well-studied case of the Bi-based cuprate family, an overall strong, monotonic doping dependence of the SB intensity at the Fermi level (E{sub F}) was observed. In contrast to a previous report for the presence of the SB only close to x = 1/8, we found it exists in a wide doping range, associated with a doping-independent ({pi},{pi}) wave vector but strongly doping-dependent intensity: It is the strongest at x {approx} 0.03 and systematically diminishes as the doping increases until it becomes negligible in the overdoped regime. This SB with the observed doping dependence of intensity can in principle be caused by the antiferromagnetic fluctuations or a particular form of low-temperature orthorhombic lattice distortion known to persist up to x {approx} 0.21 in the system, with both being weakened with increasing doping. However, a detailed binding energy dependent analysis of the SB at x = 0.07 does not appear to support the former interpretation, leaving the latter as a more plausible candidate, despite a challenge in quantitatively linking the doping dependences of the SB intensity and the magnitude of the lattice distortion. Our finding highlights the necessity of a careful and global consideration of the inherent structural complications for correctly understanding the cuprate Fermiology and its microscopic implication.

Shen, Z. X.

2011-08-15T23:59:59.000Z

9

Angle Resolved Photoemission Spectroscopy Studies of the Mott Insulator to Superconductor Evolution in Ca2-xNaxCuO2Cl2  

SciTech Connect (OSTI)

It is widely believed that many of the exotic physical properties of the high-T{sub c} cuprate superconductors arise from the proximity of these materials to the strongly correlated, antiferromagnetic Mott insulating state. Therefore, one of the fundamental questions in the field of high-temperature superconductivity is to understand the insulator-to-superconductor transition and precisely how the electronic structure of Mott insulator evolves as the first holes are doped into the system. This dissertation presents high-resolution, doping dependent angle-resolved photoemission (ARPES) studies of the cuprate superconductor Ca{sub 2-x}Na{sub x}CuO{sub 2}Cl{sub 2}, spanning from the undoped parent Mott insulator to a high-temperature superconductor with a T{sub c} of 22 K. A phenomenological model is proposed to explain how the spectral lineshape, the quasiparticle band dispersion, and the chemical potential all progress with doping in a logical and self-consistent framework. This model is based on Franck-Condon broadening observed in polaronic systems where strong electron-boson interactions cause the quasiparticle residue, Z, to be vanishingly small. Comparisons of the low-lying states to different electronic states in the valence band strongly suggest that the coupling of the photohole to the lattice (i.e. lattice polaron formation) is the dominant broadening mechanism for the lower Hubbard band states. Combining this polaronic framework with high-resolution ARPES measurements finally provides a resolution to the long-standing controversy over the behavior of the chemical potential in the high-T{sub c} cuprates. This scenario arises from replacing the conventional Fermi liquid quasiparticle interpretation of the features in the Mott insulator by a Franck-Condon model, allowing the reassignment of the position of the quasiparticle pole. As a function of hole doping, the chemical potential shifts smoothly into the valence band while spectral weight is transferred from incoherent weight at high energies to a coherent quasiparticle peak near E{sub F}. The combined shift in the chemical potential and Fermi wavevector, k{sub F}, closely corresponds to a rigid band shift into the faint excitation branch defined by the low-energy quasiparticles. In addition, the detailed doping evolution of the low-energy excitations has been studied throughout k-space. A large, hole-like contour emerges with doping, although well-defined quasiparticle peaks are only observed along a small arc around the (0, 0)-({pi},{pi}) nodal line. Near the ({pi}, 0) antinodes, faint parallel segments are found with a nesting wavevector and energy dependence very similar to the 4a{sub 0} x 4a{sub 0} checkerboard pattern observed by scanning tunneling microscopy. However, these measurements reveal a striking dichotomy between the real and momentum-space probes, where antinodal charge ordering is emphasized in the tunnelling measurements, while ARPES is most sensitive to excitations near the d-wave nodal line. These results emphasize the importance of momentum anisotropy in determining the complex electronic properties of the cuprates and places strong constraints on theoretical models of the charge ordered state.

Shen, Kyle Michael; ,

2005-09-02T23:59:59.000Z

10

An ultrafast angle-resolved photoemission apparatus for measuring complex materials  

SciTech Connect (OSTI)

We present technical specifications for a high resolution time- and angle-resolved photoemission spectroscopy setup based on a hemispherical electron analyzer and cavity-dumped solid state Ti:sapphire laser used to generate pump and probe beams, respectively, at 1.48 and 5.93 eV. The pulse repetition rate can be tuned from 209 Hz to 54.3 MHz. Under typical operating settings the system has an overall energy resolution of 23 meV, an overall momentum resolution of 0.003 A{sup -1}, and an overall time resolution of 310 fs. We illustrate the system capabilities with representative data on the cuprate superconductor Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}}. The descriptions and analyses presented here will inform new developments in ultrafast electron spectroscopy.

Smallwood, Christopher L.; Lanzara, Alessandra [Department of Physics, University of California, Berkeley, California 94720 (United States); Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Jozwiak, Christopher [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Zhang Wentao [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

2012-12-15T23:59:59.000Z

11

angled-resolved photoelectron spectroscopy: Topics by E-print...  

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

profile and nitrogen chemical bonding states,6-9,11,13,17,18 secondary ion mass spectrometry SIMS ,14 Auger electron spectroscopy,19,20 nuclear reaction analysis NRA ,21 medium...

12

angle-resolved photoelectron spectroscopies: Topics by E-print...  

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

profile and nitrogen chemical bonding states,6-9,11,13,17,18 secondary ion mass spectrometry SIMS ,14 Auger electron spectroscopy,19,20 nuclear reaction analysis NRA ,21 medium...

13

angle-resolved photoelectron spectroscopy: Topics by E-print...  

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

profile and nitrogen chemical bonding states,6-9,11,13,17,18 secondary ion mass spectrometry SIMS ,14 Auger electron spectroscopy,19,20 nuclear reaction analysis NRA ,21 medium...

14

A New Spin on Photoemission Spectroscopy  

SciTech Connect (OSTI)

The electronic spin degree of freedom is of general fundamental importance to all matter. Understanding its complex roles and behavior in the solid state, particularly in highly correlated and magnetic materials, has grown increasingly desirable as technology demands advanced devices and materials based on ever stricter comprehension and control of the electron spin. However, direct and efficient spin dependent probes of electronic structure are currently lacking. Angle Resolved Photoemission Spectroscopy (ARPES) has become one of the most successful experimental tools for elucidating solid state electronic structures, bolstered bycontinual breakthroughs in efficient instrumentation. In contrast, spin-resolved photoemission spectroscopy has lagged behind due to a lack of similar instrumental advances. The power of photoemission spectroscopy and the pertinence of electronic spin in the current research climate combine to make breakthroughs in Spin and Angle Resolved Photoemission Spectroscopy (SARPES) a high priority . This thesis details the development of a unique instrument for efficient SARPES and represents a radical departure from conventional methods. A custom designed spin polarimeter based on low energy exchange scattering is developed, with projected efficiency gains of two orders of magnitude over current state-of-the-art polarimeters. For energy analysis, the popular hemispherical analyzer is eschewed for a custom Time-of-Flight (TOF) analyzer offering an additional order of magnitude gain in efficiency. The combined instrument signifies the breakthrough needed to perform the high resolution SARPES experiments necessary for untangling the complex spin-dependent electronic structures central to today?s condensed matter physics.

Advanced Light Source; Jozwiak, Chris

2008-12-18T23:59:59.000Z

15

Extracting the spectral function of the cuprates by a full two-dimensional analysis: Angle-resolved photoemission spectra of Bi2Sr2CuO6  

SciTech Connect (OSTI)

Recently, angle-resolved photoemission spectroscopy (ARPES) has revealed a dispersion anomaly at high binding energy near 0.3-0.5 eV in various families of the high-temperature superconductors. For further studies of this anomaly we present a new two-dimensional fitting-scheme and apply it to high-statistics ARPES data of the strongly-overdoped Bi{sub 2}Sr{sub 2}CuO{sub 6} cuprate superconductor. The procedure allows us to extract the self-energy in an extended energy and momentum range. It is found that the spectral function of Bi{sub 2}Sr{sub 2}CuO{sub 6} can be parameterized using a small set of tight-binding parameters and a weakly-momentum-dependent self-energy up to 0.7 eV in binding energy and over the entire first Brillouin zone. Moreover the analysis gives an estimate of the momentum dependence of the matrix element, a quantity, which is often neglected in ARPES analyses.

Meevasana, W.

2010-04-30T23:59:59.000Z

16

E-Print Network 3.0 - angle-resolved ultraviolet photoelectron...  

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

Ph.D. March, 1994. Thesis: "Angle-Resolved Photoemission Study of Several Transition Metal... .D. 2003. Thesis: "Angle-Resolved Photoemission Study of the Elelctronic Structure...

17

A high-order harmonic generation apparatus for time- and angle-resolved photoelectron spectroscopy  

SciTech Connect (OSTI)

We present a table top setup for time- and angle-resolved photoelectron spectroscopy to investigate band structure dynamics of correlated materials driven far from equilibrium by femtosecond laser pulse excitation. With the electron-phonon equilibration time being in the order of 1–2 ps it is necessary to achieve sub-picosecond time resolution. Few techniques provide both the necessary time and energy resolution to map non-equilibrium states of the band structure. Laser-driven high-order harmonic generation is such a technique. In our experiment, a grating monochromator delivers tunable photon energies up to 40 eV. A photon energy bandwidth of 150 meV and a pulse duration of 100 fs FWHM allow us to cover the k-space necessary to map valence bands at different k{sub z} and detect outer core states.

Frietsch, B.; Gahl, C.; Teichmann, M.; Weinelt, M. [Freie Universität Berlin, Arnimallee 14, 14195 Berlin (Germany)] [Freie Universität Berlin, Arnimallee 14, 14195 Berlin (Germany); Carley, R. [Freie Universität Berlin, Arnimallee 14, 14195 Berlin (Germany) [Freie Universität Berlin, Arnimallee 14, 14195 Berlin (Germany); Max-Born-Institut, Max-Born-Str. 2a, 12489 Berlin (Germany); Döbrich, K. [Max-Born-Institut, Max-Born-Str. 2a, 12489 Berlin (Germany)] [Max-Born-Institut, Max-Born-Str. 2a, 12489 Berlin (Germany); Schwarzkopf, O.; Wernet, Ph. [Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Albert-Einstein-Str. 15, 12489 Berlin (Germany)] [Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Albert-Einstein-Str. 15, 12489 Berlin (Germany)

2013-07-15T23:59:59.000Z

18

Universal versus Material-Dependent Two-Gap Behaviors in the High-Tc Cuprates: Angle-Resolved Photoemission Study of La_2-xSr_xCuO_4  

SciTech Connect (OSTI)

We have investigated the doping and temperature dependences of the pseudogap/superconducting gap in the single-layer cuprate La{sub 2-x}Sr{sub x}CuO{sub 4} by angle-resolved photoemission spectroscopy. The results clearly exhibit two distinct energy and temperature scales, namely, the gap around ({pi}, 0) of magnitude {Delta}{asterisk} and the gap around the node characterized by the d-wave order parameter {delta}{sub 0}, like the double-layer cuprate Bi2212. In comparison with Bi2212 having higher T{sub c}'s, {delta}{sub 0} is smaller, while {delta}{asterisk} and T{ampersand} are similar. This result suggests that {delta}{asterisk} and T{asterisk} are approximately material-independent properties of a single Cu0{sub 2} plane, in contrast the material-dependent {delta}{sub 0}, representing the pairing strength.

Yoshida, T.

2010-06-04T23:59:59.000Z

19

Effects of symmetry on circular and linear magnetic dichroism in angle-resolved photoemission spectra of Gd/Y (0001) and Fe-Ni//Cu (001)  

SciTech Connect (OSTI)

We have observed circular and linear magnetic dichroism in angle- resolved photoemission spectra of 50-monolayer Gd film grown on Y(0001) and 6-monolayer Fe-Ni alloy films grown on Cu(001). The 4f level of Gd and the Fe 3p level of the Fe-Ni alloy were measured. A different geometry was used for the magnetic circular dichroism than was used to measure the magnetic linear dichroism. The geometries were chosen so that the shape of the magnetic circular dichroism is predicted to be equal to the shape of the magnetic linear dichroism for four-fold symmetric Fe-Ni/Cu(001) but not for three-fold symmetric Gd/Y(0001). Experimental results are presented. In this paper we examine the effect of symmetry (experimental geometry and sample geometry) on magnetic linear and circular dichroism in angle- resolved photoemission. In particular we chose separate geometries for measuring magnetic circular and magnetic linear dichroism. The geometries were chosen such that samples with four-fold symmetry about the sample normal may have magnetic circular and magnetic linear dichroism of the same shape. But samples with three-fold symmetry should not exhibit circular and magnetic linear dichroism of the same shape. The samples studied are three-fold symmetric Gd films grown on Y(0001) and four-fold symmetric Fe-Ni alloy grown on Cu(001). After presenting the methods of the experiment, we briefly review parts of a model of magnetic dichroism developed by Venus and coworkers and our specialization and extension of it, particularly for FeNi/Cu(001). We then show the results of our measurements.

Goodman, K.W.; Tobin, J.G.; Schumann, F.O. [Pennsylvania State Univ., University Park, PA (United States); Willis, R.F. [Pennsylvania State Univ., University Park, PA (United States); Gammon, J.W. [Virginia Commonwealth Univ., Richmond, VA (United States); Pappas, D.P. [Virginia Commonwealth Univ., Richmond, VA (United States); Kortright, J.B. [Lawrence Berkeley National Lab., CA (United States); Denlinger, J.D. [Lawrence Berkeley National Lab., CA (United States); Rotenberg, E. [Lawrence Berkeley National Lab., CA (United States); Warwick, A. [Lawrence Berkeley National Lab., CA (United States); Smith, N.V. [Lawrence Berkeley National Lab., CA (United States)

1997-03-26T23:59:59.000Z

20

Angle-resolved scattering spectroscopy of explosives using an external cavity quantum cascade laser  

SciTech Connect (OSTI)

Investigation of angle-resolved scattering from solid explosives residues on a car door for non-contact sensing geometries. Illumination with a mid-infrared external cavity quantum cascade laser tuning between 7 and 8 microns was detected both with a sensitive single point detector and a hyperspectral imaging camera. Spectral scattering phenomena were discussed and possibilities for hyperspectral imaging at large scattering angles were outlined.

Suter, Jonathan D.; Bernacki, Bruce E.; Phillips, Mark C.

2012-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "angle-resolved photoemission spectroscopy" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Circular dichroism in angle-resolved photoemission spectroscopy of topological insulators  

E-Print Network [OSTI]

Topological insulators are a new phase of matter that exhibits exotic surface electronic properties. Determining the spin texture of this class of material is of paramount importance for both fundamental understanding of ...

Wang, Yihua

22

E-Print Network 3.0 - angle-resolved photoemission spectroscopy...  

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

of a Topological Insulator Bi2Se3 with a Single Surface Dirac Cone. Summary: by Hasan and Cava detected these unusual surface states in the bismuth alloy Bi1-xSbx using...

23

Validation of angle-resolved polarized light scattering spectroscopy as a diagnostic tool for pre-cancer detection  

E-Print Network [OSTI]

Light scattering spectroscopy has emerged as a valuable diagnostic tool for cancer diagnoses in the past ten years. The interaction of light with cellular structures brings out information about morphological changes ...

Kalashnikov, Maxim M

2009-01-01T23:59:59.000Z

24

A promising concept for using near-surface measuring angles in angle-resolved x-ray photoelectron spectroscopy considering elastic scattering effects  

SciTech Connect (OSTI)

The increasing number of applications of very thin films requires both reliable thin-layer and interface characterization. A powerful method for characterization in the nanometer thickness range is the angle-resolved x-ray photoelectron spectroscopy (ARXPS). This is a nondestructive depth-profiling method, which can provide elemental content as well as chemical information. Two of the drawbacks of ARXPS are, that it requires dedicated mathematical modeling and that, at least up until now, its use has been restricted away from near-surface angles. In this paper we present a method for the mathematical description of a few, hitherto unaccounted, measurement effects in order to improve the simulations of ARXPS data for complex surface structures. As an immediate application, we propose a simple algorithm to consider the effects of elastic scattering in the standard ARXPS data interpretation, which in principle would allow the use of the whole angular range for the analysis; thus leading to a significant increase in the usable information content from the measurements. The potential of this approach is demonstrated with model calculations for a few thin film examples.

Oswald, S.; Oswald, F. [IFW Dresden, Postfach 270116, D-01171 Dresden (Germany)

2011-02-01T23:59:59.000Z

25

Angle-resolved effective potentials for disk-shaped molecules  

E-Print Network [OSTI]

We present an approach for calculating coarse-grained angle-resolved effective pair potentials for uniaxial molecules. For integrating out the intramolecular degrees of freedom we apply umbrella sampling and steered dynamics techniques in atomistically-resolved molecular dynamics (MD) computer simulations. Throughout this study we focus on disk-like molecules such as coronene. To develop the methods we focus on integrating out the van-der-Waals and intramolecular interactions, while electrostatic charge contributions are neglected. The resulting coarse-grained pair potential reveals a strong temperature and angle dependence. In the next step we fit the numerical data with various Gay-Berne-like potentials to be used in more efficient simulations on larger scales. The quality of the resulting coarse-grained results is evaluated by comparing their pair and many-body structure as well as some thermodynamic quantities self-consistently to the outcome of atomistic MD simulations of many particle systems. We find that angle-resolved potentials are essential not only to accurately describe crystal structures but also for fluid systems where simple isotropic potentials start to fail already for low to moderate packing fractions. Further, in describing these states it is crucial to take into account the pronounced temperature dependence arising in selected pair configurations due to bending fluctuations.

Thomas Heinemann; Karol Palczynski; Joachim Dzubiella; Sabine H. L. Klapp

2014-10-22T23:59:59.000Z

26

Photoemission spectroscopy study of the lanthanum lutetium oxide/silicon interface  

SciTech Connect (OSTI)

Rare earth oxides are promising candidates for future integration into nano-electronics. A key property of these oxides is their ability to form silicates in order to replace the interfacial layer in Si-based complementary metal-oxide field effect transistors. In this work a detailed study of lanthanum lutetium oxide based gate stacks is presented. Special attention is given to the silicate formation at temperatures typical for CMOS processing. The experimental analysis is based on hard x-ray photoemission spectroscopy complemented by standard laboratory experiments as Rutherford backscattering spectrometry and high-resolution transmission electron microscopy. Homogenously distributed La silicate and Lu silicate at the Si interface are proven to form already during gate oxide deposition. During the thermal treatment Si atoms diffuse through the oxide layer towards the TiN metal gate. This mechanism is identified to be promoted via Lu-O bonds, whereby the diffusion of La was found to be less important.

Nichau, A.; Schnee, M.; Schubert, J.; Bernardy, P.; Hollaender, B.; Buca, D.; Mantl, S. [Peter Gruenberg Institute 9 (PGI9-IT), Forschungszentrum Juelich, 52425 Juelich (Germany); JARA-Fundamentals of Future Information Technologies, 52425 Juelich (Germany); Besmehn, A.; Breuer, U. [Central Division for Chemical Analysis (ZCH), Forschungszentrum Juelich, 52425 Juelich (Germany); Rubio-Zuazo, J.; Castro, G. R. [Spanish CRG BM25 Beamline-SpLine, European Synchrotron Radiation Facility (ESRF), Rue Jules Horowitz BP 220, F-38043 Grenoble, Cedex 09 (France); Muecklich, A.; Borany, J. von [Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum' Dresden-Rossendorf e.V., 01314 Dresden (Germany)

2013-04-21T23:59:59.000Z

27

Time-and angle-resolved two-photon photoemission studies of electron localization  

E-Print Network [OSTI]

and solvation at interfaces P. Szymanski 1 , S. Garrett-Roe, C.B. Harris * Department of Chemistry, University Published by Elsevier Ltd. doi:10.1016/j.progsurf.2004.08.001 * Corresponding author. Tel.: +1 510 642 2814; fax: +1 510 642 6724. E-mail address: harris@socrates.berkeley.edu (C.B. Harris). 1 Present address

Harris, Charles B.

28

E-Print Network 3.0 - angle- resolved photoemission Sample Search...  

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

of a Topological Insulator Bi2Se3 with a Single Surface Dirac Cone. Summary: by Hasan and Cava detected these unusual surface states in the bismuth alloy Bi1-xSbx using...

29

E-Print Network 3.0 - angle resolved photoemission Sample Search...  

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

of a Topological Insulator Bi2Se3 with a Single Surface Dirac Cone. Summary: by Hasan and Cava detected these unusual surface states in the bismuth alloy Bi1-xSbx using...

30

angle-resolved photoemission studies: Topics by E-print Network  

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

at small cluster sizes, but decrease slightly with increasing cluster size. West, Adam H C; Luckhaus, David; Saak, Clara-Magdalena; Doppelbauer, Maximilian; Signorell, Ruth...

31

angle-resolved photoemission study: Topics by E-print Network  

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

at small cluster sizes, but decrease slightly with increasing cluster size. West, Adam H C; Luckhaus, David; Saak, Clara-Magdalena; Doppelbauer, Maximilian; Signorell, Ruth...

32

angle-resolved photoemission experiments: Topics by E-print Network  

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

The most basic theoretical challenge for understanding low energy nuclear reaction (LENR) and transmutation reaction (LETR) in condensed matters is to find mechanisms by which...

33

Widespread spin polarization effects in photoemission from topological insulators  

SciTech Connect (OSTI)

High-resolution spin- and angle-resolved photoemission spectroscopy (spin-ARPES) was performed on the three-dimensional topological insulator Bi{sub 2}Se{sub 3} using a recently developed high-efficiency spectrometer. The topological surface state's helical spin structure is observed, in agreement with theoretical prediction. Spin textures of both chiralities, at energies above and below the Dirac point, are observed, and the spin structure is found to persist at room temperature. The measurements reveal additional unexpected spin polarization effects, which also originate from the spin-orbit interaction, but are well differentiated from topological physics by contrasting momentum and photon energy and polarization dependencies. These observations demonstrate significant deviations of photoelectron and quasiparticle spin polarizations. Our findings illustrate the inherent complexity of spin-resolved ARPES and demonstrate key considerations for interpreting experimental results.

Jozwiak, C.; Chen, Y. L.; Fedorov, A. V.; Analytis, J. G.; Rotundu, C. R.; Schmid, A. K.; Denlinger, J. D.; Chuang, Y.-D.; Lee, D.-H.; Fisher, I. R.; Birgeneau, R. J.; Shen, Z.-X.; Hussain, Z.; Lanzara, A.

2011-06-22T23:59:59.000Z

34

Ultra-nonlocality in density functional theory for photo-emission spectroscopy  

SciTech Connect (OSTI)

We derive an exact expression for the photocurrent of photo-emission spectroscopy using time-dependent current density functional theory (TDCDFT). This expression is given as an integral over the Kohn-Sham spectral function renormalized by effective potentials that depend on the exchange-correlation kernel of current density functional theory. We analyze in detail the physical content of this expression by making a connection between the density-functional expression and the diagrammatic expansion of the photocurrent within many-body perturbation theory. We further demonstrate that the density functional expression does not provide us with information on the kinetic energy distribution of the photo-electrons. Such information can, in principle, be obtained from TDCDFT by exactly modeling the experiment in which the photocurrent is split into energy contributions by means of an external electromagnetic field outside the sample, as is done in standard detectors. We find, however, that this procedure produces very nonlocal correlations between the exchange-correlation fields in the sample and the detector.

Uimonen, A.-M. [Department of Physics, Nanoscience Center, University of Jyväskylä, Survontie 9, 40014 Jyväskylä (Finland)] [Department of Physics, Nanoscience Center, University of Jyväskylä, Survontie 9, 40014 Jyväskylä (Finland); Stefanucci, G. [Dipartimento di Fisica, Universitá di Roma Tor Vergata, Via della Ricerca Scientifica, 00133 Rome (Italy) [Dipartimento di Fisica, Universitá di Roma Tor Vergata, Via della Ricerca Scientifica, 00133 Rome (Italy); INFN, Laboratori Nazionali di Frascati, Via E. Fermi 40, 00044 Frascati (Italy); European Theoretical Spectroscopy Facility (ETSF), Louvain-la Neuve (Belgium); Leeuwen, R. van [Department of Physics, Nanoscience Center, University of Jyväskylä, Survontie 9, 40014 Jyväskylä (Finland) [Department of Physics, Nanoscience Center, University of Jyväskylä, Survontie 9, 40014 Jyväskylä (Finland); European Theoretical Spectroscopy Facility (ETSF), Louvain-la Neuve (Belgium)

2014-05-14T23:59:59.000Z

35

Nitrogen Doping and Thermal Stability in HfSiOxNy Studied by Photoemission and X-ray Absorption Spectroscopy  

SciTech Connect (OSTI)

We have investigated nitrogen-doping effects into HfSiO{sub x} films on Si and their thermal stability using synchrotron-radiation photoemission and x-ray absorption spectroscopy. N 1s core-level photoemission and N K-edge absorption spectra have revealed that chemical-bonding states of N-Si{sub 3-x}O{sub x} and interstitial N{sub 2}-gas-like features are clearly observed in as-grown HfSiO{sub x}N{sub y} film and they decrease upon ultrahigh vacuum (UHV) annealing due to a thermal instability, which can be related to the device performance. Annealing-temperature dependence in Hf 4f and Si 2p photoemission spectra suggests that the Hf-silicidation temperature is effectively increased by nitrogen doping into the HfSiO{sub x} although the interfacial SiO{sub 2} layer is selectively reduced. No change in valence-band spectra upon UHV annealing suggests that crystallization of the HfSiO{sub x}N{sub y} films is also hindered by nitrogen doping into the HfSiO{sub x}.

Toyoda, Satoshi; Okabayashi, Jun; Takahashi, Haruhiko; Oshima, Masaharu; /Tokyo U.; Lee, Dong-Ick; Sun, Shiyu; sun, Steven; Pianetta, Piero A.; /SLAC, SSRL; Ando, Takashi; Fukuda, Seiichi; /SONY, Atsugi

2005-12-14T23:59:59.000Z

36

E-Print Network 3.0 - angle-resolved two-dimensional mapping...  

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

Rettig... in an energy- and angle-resolved manner. To achieve this, a field free drift tube with an acceptance angle... of 22 is combined with two-dimensional position-sensitive...

37

E-Print Network 3.0 - angle-resolved x-ray photoelectron Sample...  

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

x-ray photoelectron Search Powered by Explorit Topic List Advanced Search Sample search results for: angle-resolved x-ray photoelectron Page: << < 1 2 3 4 5 > >> 1 Norman Mannella...

38

Electron mean free path from angle-dependent photoelectron spectroscopy of aerosol particles  

E-Print Network [OSTI]

We propose angle-resolved photoelectron spectroscopy of aerosol particles as an alternative way to determine the electron mean free path of low energy electrons in solid and liquid materials. The mean free path is obtained from fits of simulated photoemission images to experimental ones over a broad range of different aerosol particle sizes. The principal advantage of the aerosol approach is twofold. Firstly, aerosol photoemission studies can be performed for many different materials, including liquids. Secondly, the size-dependent anisotropy of the photoelectrons can be exploited in addition to size-dependent changes in their kinetic energy. These finite size effects depend in different ways on the mean free path and thus provide more information on the mean free path than corresponding liquid jet, thin film, or bulk data. The present contribution is a proof of principle employing a simple model for the photoemission of electrons and preliminary experimental data for potassium chloride aerosol particles.

Goldmann, Maximilian; West, Adam H C; Yoder, Bruce L; Signorell, Ruth

2015-01-01T23:59:59.000Z

39

Photoemission Study of the Rare Earth Intermetallic Compounds: RNi2Ge2 (R=Eu, Gd)  

SciTech Connect (OSTI)

EuNi{sub 2}Ge{sub 2} and GdNi{sub 2}Ge{sub 2} are two members of the RT{sub 2}X{sub 2} (R = rare earth, T = transition metal and X = Si, Ge) family of intermetallic compounds, which has been studied since the early 1980s. These ternary rare-earth intermetallic compounds with the tetragonal ThCr{sub 2}Si{sub 2} structure are known for their wide variety of magnetic properties, Extensive studies of the RT{sub 2}X{sub 2} series can be found in Refs [ 1,2,3]. The magnetic properties of the rare-earth nickel germanides RNi{sub 2}Ge{sub 2} were recently studied in more detail [4]. The purpose of this dissertation is to investigate the electronic structure (both valence band and shallow core levels) of single crystals of EuNi{sub 2}Ge{sub 2} and GdNi{sub 2}Ge{sub 2} and to check the assumptions that the f electrons are non-interacting and, consequently, the rigid-band model for these crystals would work [11], using synchrotron radiation because, to the best of our knowledge, no photoemission measurements on those have been reported. Photoemission spectroscopy has been widely used to study the detailed electronic structure of metals and alloys, and especially angle-resolved photoemission spectroscopy (ARPES) has proven to be a powerful technique for investigating Fermi surfaces (FSs) of single-crystal compounds.

Jongik Park

2004-12-19T23:59:59.000Z

40

Profiling nitrogen in ultrathin silicon oxynitrides with angle-resolved x-ray photoelectron spectroscopy  

E-Print Network [OSTI]

medium energy ion scattering and secondary ion mass spectrometry analysis. Preferential nitrogen by low energy ion (15 N2) implantation. The nitrogen profile and nitrogen chemical bonding states only minor in- crease in the dielectric constant compared to SiO2 but is still favored over other high

Gustafsson, Torgny

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41

Conduction-band electronic states of YbInCu{sub 4} studied by photoemission and soft x-ray absorption spectroscopies  

SciTech Connect (OSTI)

We have studied conduction-band (CB) electronic states of a typical valence-transition compound YbInCu{sub 4} by means of temperature-dependent hard x-ray photoemission spectroscopy (HX-PES) of the Cu 2p{sub 3/2} and In 3d{sub 5/2} core states taken at h{nu}=5.95 keV, soft x-ray absorption spectroscopy (XAS) of the Cu 2p{sub 3/2} core absorption region around h{nu}{approx}935 eV, and soft x-ray photoemission spectroscopy (SX-PES) of the valence band at the Cu 2p{sub 3/2} absorption edge of h{nu}=933.0 eV. With decreasing temperature below the valence transition at T{sub V}=42 K, we have found that (1) the Cu 2p{sub 3/2} and In 3d{sub 5/2} peaks in the HX-PES spectra exhibit the energy shift toward the lower binding-energy side by {approx}40 and {approx}30 meV, respectively, (2) an energy position of the Cu 2p{sub 3/2} main absorption peak in the XAS spectrum is shifted toward higher photon-energy side by {approx}100 meV, with an appearance of a shoulder structure below the Cu 2p{sub 3/2} main absorption peak, and (3) an intensity of the Cu L{sub 3}VV Auger spectrum is abruptly enhanced. These experimental results suggest that the Fermi level of the CB-derived density of states is shifted toward the lower binding-energy side. We have described the valence transition in YbInCu{sub 4} in terms of the charge transfer from the CB to Yb 4f states.

Utsumi, Yuki; Kurihara, Hidenao; Maso, Hiroyuki; Tobimatsu, Komei [Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526 (Japan); Sato, Hitoshi; Shimada, Kenya; Namatame, Hirofumi [Hiroshima Synchrotron Radiation Center, Hiroshima University, Higashi-Hiroshima 739-0046 (Japan); Hiraoka, Koichi [Graduate School of Science and Engineering, Ehime University, Matsuyama 790-8577 (Japan); Kojima, Kenichi [Graduate School of Integrated Arts and Sciences, Hiroshima University, Higashi-Hiroshima 739-8521 (Japan); Ohkochi, Takuo; Fujimori, Shin-ichi; Takeda, Yukiharu; Saitoh, Yuji [Synchrotron Radiation Research Center, Japan Atomic Energy Agency, Hyogo 679-5148 (Japan); Mimura, Kojiro [Graduate School of Engineering, Osaka Prefecture University, Sakai 599-8531 (Japan); Ueda, Shigenori; Yamashita, Yoshiyuki; Yoshikawa, Hideki; Kobayashi, Keisuke [NIMS Beamline Station at SPring-8, National Institute for Materials Science, Hyogo 679-5148 (Japan); Oguchi, Tamio [ISIR, Osaka University, Ibaraki 567-0047 (Japan); Taniguchi, Masaki [Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526 (Japan); Hiroshima Synchrotron Radiation Center, Hiroshima University, Higashi-Hiroshima 739-0046 (Japan)

2011-09-15T23:59:59.000Z

42

In situ photoemission spectroscopy study on formation of HfO{sub 2} dielectrics on epitaxial graphene on SiC substrate  

SciTech Connect (OSTI)

High quality HfO{sub 2} dielectrics have been grown on epitaxial graphene on 4H-SiC substrates and have been studied by using in situ x-ray photoemission spectroscopy. The in situ thermal treatment shows that the HfO{sub 2}/graphene/4H-SiC heterojunctions have good thermal stability up to 650 deg. C. A shift of core-level spectra from graphene layer implies that charge transfer takes place at the interface. The high thermal stability and sufficient barrier heights between HfO{sub 2} and graphene indicate that high-k dielectric grown on graphene is very promising for the development of graphene-based electronic devices.

Chen, Q.; Huang, H.; Chen, W.; Wee, A. T. S.; Feng, Y. P. [Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore); Chai, J. W.; Zhang, Z.; Pan, J. S.; Wang, S. J. [Institute of Materials Research and Engineering, A-STAR (Agency for Science, Technology, and Research), 3 Research Link, Singapore 117602 (Singapore)

2010-02-15T23:59:59.000Z

43

CORPES 11: International Workshop on Strong Correlations and Angle-Resolved  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed New Substation Sites Proposed Route BTRICGEGR-N Goods PO 1Photoemission

44

Direct comparative study on the energy level alignments in unoccupied/occupied states of organic semiconductor/electrode interface by constructing in-situ photoemission spectroscopy and Ar gas cluster ion beam sputtering integrated analysis system  

SciTech Connect (OSTI)

Through the installation of electron gun and photon detector, an in-situ photoemission and damage-free sputtering integrated analysis system is completely constructed. Therefore, this system enables to accurately characterize the energy level alignments including unoccupied/occupied molecular orbital (LUMO/HOMO) levels at interface region of organic semiconductor/electrode according to depth position. Based on Ultraviolet Photoemission Spectroscopy (UPS), Inverse Photoemission Spectroscopy (IPES), and reflective electron energy loss spectroscopy, the occupied/unoccupied state of in-situ deposited Tris[4-(carbazol-9-yl)phenyl]amine (TCTA) organic semiconductors on Au (E{sub LUMO}: 2.51?eV and E{sub HOMO}: 1.35?eV) and Ti (E{sub LUMO}: 2.19?eV and E{sub HOMO}: 1.69?eV) electrodes are investigated, and the variation of energy level alignments according to work function of electrode (Au: 4.81?eV and Ti: 4.19?eV) is clearly verified. Subsequently, under the same analysis condition, the unoccupied/occupied states at bulk region of TCTA/Au structures are characterized using different Ar gas cluster ion beam (Ar GCIB) and Ar ion sputtering processes, respectively. While the Ar ion sputtering process critically distorts both occupied and unoccupied states in UPS/IPES spectra, the Ar GCIB sputtering process does not give rise to damage on them. Therefore, we clearly confirm that the in-situ photoemission spectroscopy in combination with Ar GCIB sputtering allows of investigating accurate energy level alignments at bulk/interface region as well as surface region of organic semiconductor/electrode structure.

Yun, Dong-Jin, E-mail: Dongjin.yun@samsung.com; Chung, JaeGwan; Kim, Yongsu; Park, Sung-Hoon; Kim, Seong-Heon; Heo, Sung [Analytical Science Laboratory of Samsung Advanced Institute of Technology, PO Box 14-1, Yongin 446-712 (Korea, Republic of)

2014-10-21T23:59:59.000Z

45

Design of an ultrahigh vacuum transfer mechanism to interconnect an oxide molecular beam epitaxy growth chamber and an x-ray photoemission spectroscopy analysis system  

SciTech Connect (OSTI)

We designed a mechanism and the accompanying sample holders to transfer between a VEECO 930 oxide molecular beam epitaxy (MBE) and a PHI Versa Probe X-ray photoemission spectroscopy (XPS) chamber within a multiple station growth, processing, and analysis system through ultrahigh vacuum (UHV). The mechanism consists of four parts: (1) a platen compatible with the MBE growth stage, (2) a platen compatible with the XPS analysis stage, (3) a sample coupon that is transferred between the two platens, and (4) the accompanying UHV transfer line. The mechanism offers a robust design that enables transfer back and forth between the growth chamber and the analysis chamber, and yet is flexible enough to allow transfer between standard sample holders for thin film growth and masked sample holders for making electrical contacts and Schottky junctions, all without breaking vacuum. We used this mechanism to transfer a barium strontium titanate thin film into the XPS analysis chamber and performed XPS measurements before and after exposing the sample to the air. After air exposure, a thin overlayer of carbon was found to form and a significant shift ({approx}1 eV) in the core level binding energies was observed.

Rutkowski, M. M.; Zeng Zhaoquan [Department of Physics, Ohio State University, Columbus, Ohio 43210 (United States); McNicholas, K. M. [Department of Electrical and Computer Engineering, Ohio State University, Columbus, Ohio 43210 (United States); Brillson, L. J. [Department of Physics, Ohio State University, Columbus, Ohio 43210 (United States); Department of Electrical and Computer Engineering, Ohio State University, Columbus, Ohio 43210 (United States)

2013-06-15T23:59:59.000Z

46

A universal high energy anomaly in angle resolved photoemission spectra of high temperature superconductors -- possible evidence of spinon and holon branches  

E-Print Network [OSTI]

possible evidence of spinon and holon branches J. Graf, 1, 2the pro- posed spinon and holon dispersions, respectively.quasiparticles into a spinon and holon branch in the high T

2006-01-01T23:59:59.000Z

47

Nesting between hole and electron pockets in Ba(Fe1-xCox)2As2 (x=00.3) observed with angle-resolved photoemission  

E-Print Network [OSTI]

Nesting between hole and electron pockets in Ba(Fe1-xCox)2As2 (x=0­0.3) observed with angle and electrons is smaller than predicted by theory. Finally, we discuss the quality of nesting in the different regions of the phase diagram. The presence of the third hole pocket significantly weakens the nesting at x

Paris-Sud 11, Université de

48

Photoemission Spectroscopy at SRI2013  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - September 2006 TheStevenAdministration AlbumCoulomb repulsionTrimer.

49

Observation of strontium segregation in LaAlO{sub 3}/SrTiO{sub 3} and NdGaO{sub 3}/SrTiO{sub 3} oxide heterostructures by X-ray photoemission spectroscopy  

SciTech Connect (OSTI)

LaAlO{sub 3} and NdGaO{sub 3} thin films of different thicknesses have been grown by pulsed laser deposition on TiO{sub 2}-terminated SrTiO{sub 3} single crystals and investigated by soft X-ray photoemission spectroscopy. The surface sensitivity of the measurements has been tuned by varying photon energy h? and emission angle ?. In contrast to the core levels of the other elements, the Sr 3d line shows an unexpected splitting for higher surface sensitivity, signaling the presence of a second strontium component. From our quantitative analysis we conclude that during the growth process Sr atoms diffuse away from the substrate and segregate at the surface of the heterostructure, possibly forming strontium oxide.

Treske, Uwe; Heming, Nadine; Knupfer, Martin; Büchner, Bernd; Koitzsch, Andreas, E-mail: a.koitzsch@ifw-dresden.de [Institute for Solid State Research, IFW-Dresden, P.O. Box 270116, DE-01171 Dresden (Germany); Di Gennaro, Emiliano; Scotti di Uccio, Umberto; Miletto Granozio, Fabio [CNR-SPIN and Dipartimento di Fisica, Complesso Universitario di Monte S. Angelo, Via Cintia, 80126 Naples (Italy); Krause, Stefan [Helmholtz-Zentrum Berlin, BESSY, Albert-Einstein-Str. 15, 12489 Berlin (Germany)

2014-01-01T23:59:59.000Z

50

Two-Source Double-Slit Interference in Angle-Resolved High-Energy Above-Threshold Ionization Spectra of Diatoms  

SciTech Connect (OSTI)

When an electron from a diatomic molecule undergoes tunneling-rescattering ionization, a novel form of destructive interference can be realized that involves all four geometric orbits that are available to the electron when it is freed, because both ionization and rescattering may take place at the same or at different centers. We find experimentally and confirm theoretically that in orientation-averaged angle-resolved high-order above-threshold ionization spectra the corresponding destructive interference is visible for O{sub 2} but not for N{sub 2}. This effect is different from the suppression of ionization that is well known to occur for O{sub 2}.

Okunishi, M.; Itaya, R.; Shimada, K.; Pruemper, G.; Ueda, K. [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan); Busuladzic, M. [Medical Faculty, Cekalusa 90, University of Sarajevo, 71000 Sarajevo (Bosnia and Herzegowina); Gazibegovic-Busuladzic, A. [Faculty of Science, Zmaja od Bosne 35, University of Sarajevo, 71000 Sarajevo (Bosnia and Herzegowina); Milosevic, D. B. [Faculty of Science, Zmaja od Bosne 35, University of Sarajevo, 71000 Sarajevo (Bosnia and Herzegowina); Max-Born-Institut, Max-Born-Strasse 2a, 12489 Berlin (Germany); Becker, W. [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan); Max-Born-Institut, Max-Born-Strasse 2a, 12489 Berlin (Germany)

2009-07-24T23:59:59.000Z

51

A novel approach for the characterization of a bilayer of phenyl-c71-butyric-acid-methyl ester and pentacene using ultraviolet photoemission spectroscopy and argon gas cluster ion beam sputtering process  

SciTech Connect (OSTI)

The material arrangement and energy level alignment of an organic bilayer comprising of phenyl-c71-butyric-acid-methyl ester (PCBM-71) and pentacene were studied using ultraviolet photoelectron spectroscopy (UPS) and the argon gas cluster ion beam (GCIB) sputtering process. Although there is a small difference in the full width at half maximum of the carbon C 1s core level peaks and differences in the oxygen O 1s core levels of an X-ray photoemission spectroscopy spectra, these differences are insufficient to clearly distinguish between PCBM-71 and pentacene layers and to classify the interface and bulk regions. On the other hand, the valence band structures in the UPS spectra contain completely distinct configurations for the PCBM-71 and pentacene layers, even when they have similar atomic compositions. According to the valence band structures of the PCBM-71/pentacene/electrodes, the highest unoccupied molecular orbital (HOMO) region of pentacene is at least 0.8 eV closer to the Fermi level than that of PCBM-71 and it does not overlap with any of the chemical states in the valence band structure of PCBM-71. Therefore, by just following the variations in the area of the HOMO region of pentacene, the interface/bulk regions of the PCBM/pentacene layers were distinctly categorized. Besides, the variation of valence band structures as a function of the Ar GCIB sputtering time fully corroborated with the surface morphologies observed in the atomic force microscope images. In summary, we believe that the novel approach, which involves UPS analysis in conjunction with Ar GCIB sputtering, can be one of the best methods to characterize the material distribution and energy level alignments of stacks of organic layers.

Yun, Dong-Jin; Chung, JaeGwan; Jung, Changhoon; Chung, Yeonji; Kim, SeongHeon; Lee, Seunghyup; Kim, Ki-Hong; Han, Hyouksoo; Park, Gyeong-Su; Park, SungHoon [Analytical Science Laboratory of Samsung Advanced Institute of Technology, P.O. Box 14-1, Yongin 446-712 (Korea, Republic of)] [Analytical Science Laboratory of Samsung Advanced Institute of Technology, P.O. Box 14-1, Yongin 446-712 (Korea, Republic of)

2013-09-07T23:59:59.000Z

52

Study of hard disk and slider surfaces using X-ray photoemission electron microscopy and near-edge X-ray absorption fine structure spectroscopy  

SciTech Connect (OSTI)

X-ray Photo Emission Electron Microscopy (X-PEEM) and Near Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy were applied to study the properties of amorphous hard carbon overcoats on disks and sliders, and the properties of the lubricant. The modification of lubricants after performing thermal desorption studies was measured by NEXAFS, and the results are compared to the thermal desorption data. The study of lubricant degradation in wear tracks is described. Sliders were investigated before and after wear test, and the modification of the slider coating as well as the transfer of lubricant to the slider was studied. The studies show that the lubricant is altered chemically during the wear. Fluorine is removed and carboxyl groups are formed.

Anders, S.; Stammler, T. [Lawrence Berkeley National lab., CA (United States). Advanced Light Source Div.; Bhatia, C.S. [SSD/IBM, San Jose, CA (United States); Stoehr, J. [IBM Research Div., San Jose, CA (United States). Almaden Research Center; Fong, W.; Chen, C.Y.; Bogy, D.B. [Univ. of California, Berkeley, CA (United States)

1998-04-01T23:59:59.000Z

53

Bond stretching phonon softening and angle-resolved photoemission kinks in optimally doped Bi2Sr1:6La0:4Cu2O6+sigma superconductors  

E-Print Network [OSTI]

La 0.4 Cu 2 O 6+? superconductors J. Graf, 1 M. d’Astuto, 2softening is related to superconductivity or to the strongtransition in cuprates superconductors [1–4, 6, 7] as well

Graf, Jeff

2008-01-01T23:59:59.000Z

54

Direct observation of a dispersionless impurity band in hydrogenated graphene  

E-Print Network [OSTI]

We show with angle-resolved photoemission spectroscopy that a new energy band appears in the electronic structure of electron-doped hydrogenated monolayer graphene (H-graphene). Its occupation can be controlled with the ...

Haberer, D.

55

Watching Electrons Transfer from Metals to Insulators using Two Photon Photoemission  

SciTech Connect (OSTI)

Ultrafast angle-resolved two photon photoemission was used to study the dynamics and interfacial band structure of ultrathin films adsorbed onto Ag(111). Studies focused on the image potential state (IPS) in each system as a probe for measuring changes in electronic behavior in differing environments. The energetics and dynamics of the IPS at the toluene/Ag(111) interface are strongly dependent upon coverage. For a single monolayer, the first IPS is bound by 0.81 eV below the vacuum level and has a lifetime of 50 femtoseconds (fs). Further adsorption of toluene creates islands of toluene with an exposed wetting layer underneath. The IPS is then split into two peaks, one corresponding to the islands and one corresponding to the monolayer. The wetting layer IPS shows the same dynamics as the monolayer, while the lifetime of the islands increases exponentially with increasing thickness. Furthermore, the island IPS transitions from delocalized to localized within 500 fs, and electrons with larger parallel momenta decay much faster. Attempts were made using a stochastic model to extract the rates of localization and intraband cooling at differing momenta. In sexithiophene (6T) and dihexyl-sexithiophene (DH6T), the IPS was used as a probe to see if the nuclear motion of spectating side chains can interfere with molecular conduction. The energy and band mass of the IPS was measured for 6T and two geometries of DH6T on Ag(111). Electrons injected into the thicker coverages of DH6T grew exponentially heavier until they were completely localized by 230 fs, while those injected into 6T remained nearly free electron like. Based off of lifetime arguments and the density of defects, the most likely cause for the mass enhancement of the IPS in this system is small polaron formation caused by coupling of the electron to vibrations of the alkyl substituents. The energetic relaxation of the molecular adsorbate was also measured to be 20 meV/100 fs for the DH6T, and 0 meV/100 fs for the 6T. This relaxation is consistent with the localization of the charge creating a barrier for it moving from one lattice site to a neighboring one. Finally, the IPS was used to study the evolution of the surface band gap at the Mg/Ag(111) interface. The Mg(0001) surface band gap lies 1.6 eV below the Fermi level, and consequently shows no peak in the projected density of states for the IPS. A method for creating layer by layer growth of Mg on Ag(111) was determined using Auger Spectroscopy and low energy electron diffraction. By monitoring the decay of the intensity of the IPS versus coverage, it was determined that four layers of magnesium on Ag(111) is sufficient to completely eliminate the surface band gap

Johns, James E.

2010-05-01T23:59:59.000Z

56

Comparison of magnetic linear dichroism in 4f photoemission and 4d{endash}4f photoemission from Gd on Y(0001)  

SciTech Connect (OSTI)

Magnetic linear dichroism (MLD) in 4d{endash}4f resonant and 4f nonresonant photoemission (PE) is studied from thin epitaxial gadolinium films. In an angle resolved and high-energy resolution mode, experiments were conducted with the electric-field vector of the incident light perpendicular to the sample magnetization. Our results show a significant difference in behavior of MLD in resonant PE as compared to that in nonresonant PE. Off-resonance, the MLD signal is dominated by a negative feature at the low binding energy side of the peak. Near the 4d{endash}4f resonance maximum, the MLD displays a plus{endash}minus shape, with a negative signal at the low binding energy side of the 4f peak and a positive signal at the high binding energy side. Analysis of MLD in 4d{endash}4f resonant PE may provide insight into interactions of the 4d core hole with the 4f core level in the intermediate state. {copyright} {ital 1997 American Vacuum Society.}

Gammon, W.J.; Mishra, S.R.; Pappas, D.P. [Department of Physics, Virginia Commonwealth University, Richmond, Virginia 23284-2000 (United States)] [Department of Physics, Virginia Commonwealth University, Richmond, Virginia 23284-2000 (United States); Goodman, K.W.; Tobin, J.G. [Lawrence Livermore National Laboratory, Lawrence Livermore, California 93550 (United States)] [Lawrence Livermore National Laboratory, Lawrence Livermore, California 93550 (United States); Schumann, F.O.; Willis, R. [Department of Physics, Pennsylvania State University, University Park, Pennsylvania 16802 (United States)] [Department of Physics, Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Denlinger, J.D.; Rotenberg, E.; Warwick, A.; Smith, N.V. [Advanced Light Source, Lawrence Berkeley Laboratory, Berkeley, California 94720 (United States)] [Advanced Light Source, Lawrence Berkeley Laboratory, Berkeley, California 94720 (United States)

1997-05-01T23:59:59.000Z

57

Electronic states of NO{sub 2}-exposed H-terminated diamond/Al{sub 2}O{sub 3} heterointerface studied by synchrotron radiation photoemission and X-ray absorption spectroscopy  

SciTech Connect (OSTI)

The energy band-lineup and the electronic structure of NO{sub 2}-exposed H-terminated diamond/Al{sub 2}O{sub 3} heterointerface have been investigated by synchrotron radiation photoemission and x-ray absorption near-edge structure (XANES) measurements. It is found that the energy band-lineup is stagger-type, so-called type-II, with its valence band discontinuity of as high as 3.9?eV and its conduction band discontinuity of 2.7?eV. The valence band maximum of the H-terminated diamond surface is positioned at Fermi level as a result of high-density hole accumulation on the diamond side. The XANES measurement has shown that the oxygen-derived interface state locates at about 1–3?eV above the Fermi level.

Takahashi, Kazutoshi; Imamura, Masaki [Synchrotron Light Application Center, Saga University, Saga 840-8502 (Japan); Hirama, Kazuyuki [NTT Basic Research Laboratories, NTT Corporation, Atsugi 243-0198 (Japan); Kasu, Makoto [Department of Electrical and Electronic Engineering, Saga University, Saga 840-8502 (Japan)

2014-02-17T23:59:59.000Z

58

A fermi liquid electric structure and the nature of the carriers in high-T/sub c/ cuprates: A photoemission study  

SciTech Connect (OSTI)

We have performed angle-integrated and angle-resolved photoemission measurements at 20 K on well-characterized single crystals of high-T/sub c/ cuprates (both 1:2:3-type and 2:2:1:2-type) cleaved in situ, and find a relatively large, resolution limited Fermi edge which shows large amplitude variations with photon energy, indicative of band structure final state effects. The lineshapes of the spectra of the 1:2:3 materials as a function of photon energy are well reproduced by band structure predictions, indicating a correct mix of 2p and 3d orbitals on the calculations, while the energy positions of the peaks agree with calculated bands only to within /approx/0.5 eV. This may yet prove to reflect the effects of Coulomb correlation. We nevertheless conclude that a Fermi liquid approach to conductivity is appropriate. Angle-resolved data, while still incomplete, suggest agreement with the Fermi surface predicted by the LDA calculations. A BCS-like energy gap is observed in the 2:2:1:2 materials, whose magnitude is twice the weak coupling BCS value (i.e., 2/Delta/ = 7 KT/sub c/). 49 refs., 11 figs.

Arko, A.J.; List, R.S.; Bartlett, R.J.; Cheong, S.W.; Fisk, Z.; Thompson, J.D.; Olson, C.G.; Yang, A.B.; Liu, R.; Gu, C.; Veal, B.W.; Liu, J.Z.; Paulikas, A.P.; Vandervoort, K.; Claus, H.; Campuzano, J.C.; Schirber, J.E.; Shinn, N.D.

1989-01-01T23:59:59.000Z

59

Linear dichroism and resonant photoemission in Gd 011  

SciTech Connect (OSTI)

Magnetic Linear Dichroism in Angular Distributions (MLDAD) from Photoelectron Emission was used to probe the nature of Resonant Photoemission. Gd 5p and Gd 4f emission were investigated. Using novel theoretical simulations, we were able to show that temporal matching is a requirement for ``True`` Resonant Photoemission, where the Resonant Photoemission retains the characteristics of Photoelectron Emission.

Mishra, S.R.; Cummins, T.R.; Gammon, W.J.; van der Laan, G.; Goodman, K.W.; Tobin, J.G.

1998-05-13T23:59:59.000Z

60

A medium-energy photoemission and ab-initio investigation of cubic yttria-stabilised zirconia  

SciTech Connect (OSTI)

Experimental and theoretical investigations into the electronic properties and structure of cubic yttria-stabilized zirconia are presented. Medium-energy x-ray photoemission spectroscopy measurements have been carried out for material with a concentration of 8-9?mol.?% yttria. Resonant photoemission spectra are obtained for a range of photon energies that traverse the L2 absorption edge for both zirconium and yttrium. Through correlation with results from density-functional theory (DFT) calculations, based on structural models proposed in the literature, we assign photoemission peaks appearing in the spectra to core lines and Auger transitions. An analysis of the core level features enables the identification of shifts in the core level energies due to different local chemical environments of the constituent atoms. In general, each core line feature can be decomposed into three contributions, with associated energy shifts. Their identification with results of DFT calculations carried out for proposed atomic structures, lends support to these structural models. The experimental results indicate a multi-atom resonant photoemission effect between nearest-neighbour oxygen and yttrium atoms. Near-edge x-ray absorption fine structure spectra for zirconium and yttrium are also presented, which correlate well with calculated Zr- and Y-4d electron partial density-of-states and with Auger electron peak area versus photon energy curve.

Cousland, G. P. [School of Physics, The University of Sydney, New South Wales 2006 (Australia); Australian Nuclear Science and Technology Organisation, Lucas Heights, New South Wales 2234 (Australia); Cui, X. Y. [School of Physics, The University of Sydney, New South Wales 2006 (Australia); Australian Centre for Microscopy and Microanalysis, The University of Sydney, New South Wales 2006 (Australia); Smith, A. E. [School of Physics, Monash University, Clayton, Victoria 3800 (Australia); Stampfl, C. M. [School of Physics, The University of Sydney, New South Wales 2006 (Australia); School of Materials Science and Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of); Wong, L.; Tayebjee, M.; Yu, D.; Triani, G.; Evans, P. J. [Australian Nuclear Science and Technology Organisation, Lucas Heights, New South Wales 2234 (Australia); Ruppender, H.-J. [OmniVac GmbH, Espensteigstrasse 16, 67661 Kaiserslautern (Germany); Jang, L.-Y. [National Synchrotron Radiation Research Center, Hsinchu Science Park, Hsinchu 30076, Taiwan (China); Stampfl, A. P. J. [Australian Nuclear Science and Technology Organisation, Lucas Heights, New South Wales 2234 (Australia); School of Chemistry, The University of Sydney, New South Wales 2006 (Australia)

2014-04-14T23:59:59.000Z

Note: This page contains sample records for the topic "angle-resolved photoemission spectroscopy" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Spectroscopy  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassiveSubmittedStatus Tom Fletcher,Future |CarlosSpeakersSpectroscopy Print In

62

E-Print Network 3.0 - ambient pressure photoemission Sample Search...  

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

Sciences and Ecology 20 CLNS 031827 VERY HIGH VOLTAGE PHOTOEMISSION ELECTRON GUNS* Summary: CLNS 031827 VERY HIGH VOLTAGE PHOTOEMISSION ELECTRON GUNS* Charles K....

63

CLNS 03/1827 VERY HIGH VOLTAGE PHOTOEMISSION ELECTRON GUNS*  

E-Print Network [OSTI]

photoemission electron guns, will be reviewed. INTRODUCTION The successful demonstration of beam energy recovery with demanding specifications on transverse and longitudinal emittances. DC electron guns with photoemission, there are few restrictions on vacuum chamber geometry or the location and size of ports, and many choices

64

Widespread spin polarizationeffects in photoemission from topological insulators  

E-Print Network [OSTI]

photoemission from topological insulators C. Jozwiak, 1, ?approach in the 3D topological insulators. [1] D. Hsieh, D.three-dimensional topological insulator Bi 2 Se 3 using a

Jozwiak, C.

2012-01-01T23:59:59.000Z

65

Fermi-level tuning of topological insulator thin films Masaki Aitani,1  

E-Print Network [OSTI]

Fermi-level tuning of topological insulator thin films Masaki Aitani,1 Yusuke Sakamoto,1 Toru Topological insulators are insulating materials but have metallic edge states with peculiar prop- erties properties of topological insulator ultrathin Bi2Te3 films by angle-resolved photoemission spectroscopy

Hasegawa, Shuji

66

E-Print Network 3.0 - accuracy electron-impact photoemission...  

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

results for: accuracy electron-impact photoemission Page: << < 1 2 3 4 5 > >> 1 SRI 2007 Conference Proceedings Title: High Resolution Photoemission of Organic Systems at 3m NIM...

67

Distinct spinon and holon dispersions in photoemission spectral functions from  

E-Print Network [OSTI]

ARTICLES Distinct spinon and holon dispersions in photoemission spectral functions from one particles) called spinons and holons. Experimentalists have long sought to verify this effect. Angle quasiparticle peak splits into a spinon­holon two-peak- like structure. Despite extensive ARPES experiments

Loss, Daniel

68

Dynamic Characterization of Graphene Growth and Etching by Oxygen on Ru(0001) by Photoemission Electron Microscopy  

E-Print Network [OSTI]

Dynamic Characterization of Graphene Growth and Etching by Oxygen on Ru(0001) by Photoemission of graphene on Ru(0001) was investigated by photoemission electron microscopy (PEEM) and scanning tunneling, we show that graphene overlayers with sizes ranging from nanometers to sub-millimeters have been

Bao, Xinhe

69

Effects, determination, and correction of count rate nonlinearity in multi-channel analog electron detectors  

SciTech Connect (OSTI)

Detector counting rate nonlinearity, though a known problem, is commonly ignored in the analysis of angle resolved photoemission spectroscopy where modern multichannel electron detection schemes using analog intensity scales are used. We focus on a nearly ubiquitous “inverse saturation” nonlinearity that makes the spectra falsely sharp and beautiful. These artificially enhanced spectra limit accurate quantitative analysis of the data, leading to mistaken spectral weights, Fermi energies, and peak widths. We present a method to rapidly detect and correct for this nonlinearity. This algorithm could be applicable for a wide range of nonlinear systems, beyond photoemission spectroscopy.

Reber, T. J.; Plumb, N. C.; Waugh, J. A.; Dessau, D. S. [Department of Physics, University of Colorado, Boulder, Colorado 80309-0390 (United States)] [Department of Physics, University of Colorado, Boulder, Colorado 80309-0390 (United States)

2014-04-15T23:59:59.000Z

70

Photoemission study of energy-band alignment for RuO{sub x}/HfO{sub 2}/Si system  

SciTech Connect (OSTI)

Conductive oxides RuO{sub x} as alternative electrode on high-{kappa} HfO{sub 2} gate dielectric have been fabricated by ultrahigh-vacuum sputtering and subsequently oxidized using oxygen plasma. The energy-band alignment for the RuO{sub x}/HfO{sub 2}/Si system and the oxidation-state dependence of barrier height for RuO{sub x} contacting to HfO{sub 2} dielectrics has been analyzed by x-ray photoemission spectroscopy. The valence- and conduction-band offsets of HfO{sub 2}/Si are determined to be 3.05{+-}0.1 and 1.48{+-}0.1 eV, respectively. The barrier heights for the RuO{sub x} contacting to HfO{sub 2} are oxidation-state dependent, in the range of 1.95-2.73 eV.

Li, Q.; Wang, S.J.; Li, K.B.; Huan, A.C.H.; Chai, J.W.; Pan, J.S.; Ong, C.K. [Department of Physics, National University of Singapore, Singapore 117542 (Singapore); Institute of Materials Research and Engineering, 3 Research Link, Singapore 117602 (Singapore); Data Storage Institute, DSI Building, 5 Engineering Drive 1, Singapore 117608 (Singapore); Institute of Materials Research and Engineering, 3 Research Link, Singapore 117602, Singapore and Department of Physics, National University of Singapore, Singapore 117542 (Singapore); Institute of Materials Research and Engineering, 3 Research Link, Singapore 117602 (Singapore); Department of Physics, National University of Singapore, Singapore 117542 (Singapore)

2004-12-20T23:59:59.000Z

71

CHEMISTRY OF SO{sub 2} ON MODEL METAL AND OXIDE CATALYSTS: PHOTOEMISSION AND XANES STUDIES  

SciTech Connect (OSTI)

High-resolution synchrotron based photoemission and x-ray absorption spectroscopy have been used to study the interaction of SO{sub 2} with a series of metals and oxides. The chemistry of SO{sub 2} on metal surfaces is rich. At low coverages, the molecule fully decomposes into atomic S and O. At large coverages, the formation of SO{sub 3} and SO{sub 4} takes place. The following sequence was found for the reactivity of the metals towards SO{sub 2}: Pt {approx} Rh < Ru < Mo << Zn, Sn, Cs. Alloying can be useful for reducing the chemical affinity of a metal for SO{sub 2} and controlling S poisoning. Pd atoms bonded to Rh and Pt atoms bonded to Sn interact weakly with SO{sub 2}. In general, SO{sub 2} mainly reacts with the O centers of metal oxides. SO{sub 4} is formed on CeO{sub 2} and SO{sub 3} on ZnO. On these systems there is no decomposition of SO{sub 2}. Dissociation of the molecule is observed after introducing a large amount of Ce{sup 3+} sites in ceria, or after depositing Cu or alkali metals on the oxide surfaces. These promote the catalytic activity of the oxides during the destruction of SO{sub 2}.

RODRIGUEZ,J.A.; JIRSAK,T.; CHATURVEDI,S.; HRBEK,J.; FREITAG,A.; LARESE,J.Z.

2000-07-09T23:59:59.000Z

72

Electronic structure of Co-Ni-Ga Heusler alloys studied by resonant photoemission  

SciTech Connect (OSTI)

The electronic structures of Co{sub 2.01}Ni{sub 1.05}Ga{sub 0.94} and Co{sub 1.76}Ni{sub 1.46}Ga{sub 0.78} Heusler alloys have been investigated by resonant photoemission spectroscopy across the 3p-3d transition of Co and Ni. For the Ni excess composition Co{sub 1.76}Ni{sub 1.46}Ga{sub 0.78}, the valence band peak shows a shift of 0.25 eV as compared to the near stoichiometric composition Co{sub 2.01}N1{sub 1.05}Ga{sub 0.94}. Also an enhancement is observed in the Ni related satellite features in the valence band for the Ni excess composition. Due to hybridization of Co and Ni 3d states in these systems, the Co and Ni 3p-3d resonance energies are found to be higher as compared to Co and Ni metals. Theoretical first principle calculation is performed to understand the features in the valence band and the shape of the resonance profile.

Baral, Madhusmita, E-mail: madhusmita@rrcat.gov.in; Banik, Soma, E-mail: madhusmita@rrcat.gov.in; Ganguli, Tapas, E-mail: madhusmita@rrcat.gov.in; Chakrabarti, Aparna, E-mail: madhusmita@rrcat.gov.in; Deb, S. K. [Indus Synchrotrons Utilization Division, Raja Ramanna Centre for Advanced Technology, Indore-452013 (India); Thamizhavel, A. [Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005 (India); Wadikar, Avinash; Phase, D. M. [UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore-452017 (India)

2014-04-24T23:59:59.000Z

73

Spin injection and spin dynamics at the CuPc/GaAs interface studied with ultraviolet photoemission spectroscopy and two-photon photoemission spectroscopy  

E-Print Network [OSTI]

to the device dimensions with- out loss of the spin polarization, which is most commonly defined experimentally in space. Novel magnetoresistive devices using semiconductor spacer materials are generally based

Aeschlimann, Martin

74

Symmetry Breaking in Few Layer Graphene Films  

SciTech Connect (OSTI)

Recently, it was demonstrated that the quasiparticledynamics, the layer-dependent charge and potential, and the c-axisscreening coefficient could be extracted from measurements of thespectral function of few layer graphene films grown epitaxially on SiCusing angle-resolved photoemission spectroscopy (ARPES). In this articlewe review these findings, and present detailed methodology for extractingsuch parameters from ARPES. We also present detailed arguments againstthe possibility of an energy gap at the Dirac crossing ED.

Bostwick, A.; Ohta, T.; McChesney, J.L.; Emtsev, K.; Seyller,Th.; Horn, K.; Rotenberg, E.

2007-05-25T23:59:59.000Z

75

A photoemission study of Au, Ge, and O{sub 2} deposition on NH{sub 4}F etched Si(111)  

SciTech Connect (OSTI)

We have studied the interaction of a metal, Au, a semiconductor, Ge, and a non-metal, O{sub 2}, with the NH{sub 4}F etched Si(111) surface with photoemission spectroscopy. Two components were present in Si 2p core level spectra from the H-terminated surface. We observed the flat band condition from the as-etched, n-type, Si(111) surface. We performed stepwise depositions of Au and measured the band bending with photoemission spectroscopy. The Fermi level pinned near mid-gap as Au was deposited onto the as-etched surface. After the deposition of 1 ML of Au, a Au-silicide layer formed. This interfacial component indicated that the passivating H layer was compromised. As the Au coverage was increased, layers of pure Au formed between the bulk silicon and the Au-silicide layer. The observed behavior was nearly identical to that of Au deposition on the Si(111) 7 {times} 7 surface. Next, we tested the ability of the monohydride layer to sustain surfactant assisted growth of Ge. Ge islanding was observed at 400{degree}C indicating that good surfactant growth was not obtained. Although the monohydride layer was not a good surfactant for the Si(111) surface at this temperature, further study at different temperatures is needed to determine the ability of the ideal monohydride layer to act as a surfactant. Finally, we observed no oxidation of the as-etched surface at room temperature upon exposure to molecular oxygen.

Terry, J.; Cao, R.; Wigren, C.; Pianetta, P.

1994-03-01T23:59:59.000Z

76

E-Print Network 3.0 - angle-scanning photoemission end-station...  

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

for: angle-scanning photoemission end-station Page: << < 1 2 3 4 5 > >> 1 SRI 2007 Conference Proceedings Title: Optimization of the 3m TGM beamline, at CAMD, for constant...

77

Nonlinear Photoemission Electron Micrographs of Plasmonic Nanoholes in Gold Thin Films  

SciTech Connect (OSTI)

Nonlinear photoemission electron microscopy of isolated nanoholes in gold thin films map propagating surface plasmon polaritons (SPPs) launched from the lithographically patterned plasmonic structures. A damped sinusoidal elongated ring-like photoemission beat pattern is observed from the nanoholes, following low angle of incidence irradiation of these structures with sub-15 fs 780 nm laser pulses. A notable agreement between finite difference time domain simulations and experiment corroborates our assignment of the observed photoemission patterns to SPPs launched from isolated nanoholes and probed through nonlinear photoemission. We also demonstrate how the efficiency of coupling light waves into isolated plasmonic holes can be tuned by varying hole diameter. In this regard, a simple intuitive geometrical model, which accounts for the observed and simulated diameter dependent plasmonic response, is proposed. Overall, this study paves the way for designing nanohole assemblies where optical coupling and subsequent plasmon propagation can be rationally controlled through 2D SPP interferometry

Gong, Yu; Joly, Alan G.; El-Khoury, Patrick Z.; Hess, Wayne P.

2014-11-06T23:59:59.000Z

78

Photoelectron Spectroscopy under Ambient Pressure and Temperature Conditions  

SciTech Connect (OSTI)

We describe the development and applications of novel instrumentation for photoemission spectroscopy of solid or liquid surfaces in the presence of gases under ambient conditions or pressure and temperature. The new instrument overcomes the strong scattering of electrons in gases by the use of an aperture close to the surface followed by a differentially-pumped electrostatic lens system. In addition to the scattering problem, experiments in the presence of condensed water or other liquids require the development of special sample holders to provide localized cooling. We discuss the first two generations of Ambient Pressure PhotoEmission Spectroscopy (APPES) instruments developed at synchrotron light sources (ALS in Berkeley and BESSY in Berlin), with special focus on the Berkeley instruments. Applications to environmental science and catalytic chemical research are illustrated in two examples.

Ogletree, D. Frank; Bluhm, Hendrik; Hebenstreit, Eleonore B.; Salmeron, Miquel

2009-02-27T23:59:59.000Z

79

Vacuum space charge effect in laser-based solid-state photoemission spectroscopy  

E-Print Network [OSTI]

markers. The solid lines are ?ts to a power law. The datadeviations. The solid lines are ?ts to a power law. We ?tdeviations. The solid lines are ?ts to a power law. V.

Graf, Jeff

2010-01-01T23:59:59.000Z

80

PHOTOEMISSION YIELD SPECTROSCOPY OF METAL ELECTRODES J. K. SASS and H. 5. LEWERENZ  

E-Print Network [OSTI]

character of the metal-electrolyte contact with a variable threshold for electron emission allows with various electrolytes was heavily emphasized. Therefore the thermalization of hot electrons, the formation of solvated electrons and their subsequent chemical and electrochemical reac- tions were extensively

Boyer, Edmond

Note: This page contains sample records for the topic "angle-resolved photoemission spectroscopy" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Electronic structure of ScN determined using optical spectroscopy, photoemission, and ab initio calculations  

E-Print Network [OSTI]

calculations for transition-metal TM nitrides and carbides. In addition, it is well known5 that LDA seriously dielectric function 2 consists of two primary features due to direct X- and -point transitions at photon- density-approximation LDA for the exchange-correlation potential, respectively, predict metallic

Gall, Daniel

82

Anomalous temperature dependence in valence band spectra: A resonant photoemission study of layered perovskite Sr{sub 2}CoO{sub 4}  

SciTech Connect (OSTI)

Valence band spectra (VBS) and its modification across Curie temperature (T{sub C}) of Sr{sub 2}CoO{sub 4} thin film are studied using resonant photoemission spectroscopy. It is found that VBS mainly consists of hybridized states of Co-3d t{sub 2g}e{sub g} and O-2p; however, Co-3d e{sub g} states show its prominence only in the ferromagnetic temperature regime. Below T{sub C}, spectral weight transfer takes place anomalously from high binding energy (B.E.) region to low B.E. region, signifying the enhanced intermediate or low spin state Co{sup 4+} ions. It is suggested that spin-lattice coupling and many-body effects in Sr{sub 2}CoO{sub 4} derived from the strong electron correlations lead to such temperature dependence of VBS.

Pandey, Pankaj K.; Choudhary, R. J., E-mail: ram@csr.res.in; Phase, D. M. [UGC DAE Consortium for Scientific Research, University Campus, Indore 452001 (India)

2014-05-05T23:59:59.000Z

83

A combined droplet train and ambient pressure photoemission spectrometer for the investigation of liquid/vapor interfaces  

SciTech Connect (OSTI)

We describe a combined ambient pressure photoelectron spectroscopy/droplet train apparatus for investigating the nature and heterogeneous chemistry of liquid/vapor interfaces. In this instrument a liquid droplet train with typical droplet diameters from 50...150 {micro}m is produced by a vibrating orifice aerosol generator (VOAG). The droplets are irradiated by soft X-rays (100...1500 eV) in front of the entrance aperture of a differentially pumped electrostatic lens system that transfers the emitted electrons into a conventional hemispherical electron analyzer. The photoemission experiments are performed at background pressures of up to several Torr, which allows the study of environmentally important liquid/vapor interfaces, in particular aqueous solutions, under equilibrium conditions. The exposure time of the droplet surface to the background gases prior to the XPS measurement can be varied, which will allow future kinetic measurements of gas uptake on liquid surfaces. As an example, a measurement of the surface composition of a {chi} = 0.21 aqueous methanol solution is presented. The concentration of methanol at the vapor/liquid interface is enhanced by a factor of about 3 over the bulk value, while the expected bulk value is recovered at depths larger than about 1.5 nm.

Starr, David E.; Wong, Ed K.; Worsnop, Douglas R.; Wilson, Kevin R.; Bluhm, Hendrik

2008-05-01T23:59:59.000Z

84

SPIN POLARIZED PHOTOELECTRON SPECTROSCOPY AS A PROBE OF MAGNETIC SYSTEMS.  

SciTech Connect (OSTI)

Spin-polarized photoelectron spectroscopy has developed into a versatile tool for the study of surface and thin film magnetism. In this chapter, we examine the methodology of the technique and its recent application to a number of different problems. We first examine the photoemission process itself followed by a detailed review of spin-polarization measurement techniques and the related experimental requirements. We review studies of spin polarized surface states, interface states and quantum well states followed by studies of the technologically important oxide systems including half-metallic transition metal oxides, ferromagnet/oxide interfaces and the antiferromagnetic cuprates that exhibit high Tc Superconductivity. We also discuss the application of high-resolution photoemission with spin resolving capabilities to the study of spin dependent self energy effects.

JOHNSON, P.D.; GUNTHERODT, G.

2006-11-01T23:59:59.000Z

85

Solar energy conversion via hot electron internal photoemission in metallic nanostructures: Efficiency estimates  

E-Print Network [OSTI]

Solar energy conversion via hot electron internal photoemission in metallic nanostructures://scitation.aip.org/termsconditions. Downloaded to ] IP: 131.215.44.236 On: Tue, 01 Apr 2014 22:46:10 #12;Solar energy conversion via hot electron for the construction of solar energy-conversion devices. Herein, we evaluate theoretically the energy

Atwater, Harry

86

Optimisation of NSLS-II Blade X-ray Beam Position Monitors: from Photoemission type to Diamond Detector  

SciTech Connect (OSTI)

Optimisation of blade type x-ray beam position monitors (XBPM) was performed for NSLS-II undulator IVU20. Blade material, con and #64257;guration and operation principle was analysed in order to improve XBPM performance. Optimisation is based on calculation of the XBPM signal spatial distribution. Along with standard photoemission type XBPM a Diamond Detector Blades (DDB) were analysed as blades for XBPMs. DDB XBPMs can help to overcome drawbacks of the photoemission blade XBPMs.

ILINSKI P.

2012-07-10T23:59:59.000Z

87

Spectroscopy and Diffraction | EMSL  

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

and Techniques Electron spectroscopy Electron backscatter diffraction Atom probe tomography Ionmolecular beam spectroscopy 57Fe-Mssbauer spectroscopy Optical spectroscopy...

88

Effects of a modular two-step ozone-water and annealing process on silicon carbide graphene  

SciTech Connect (OSTI)

By combining ozone and water, the effect of exposing epitaxial graphene on silicon carbide to an aggressive wet-chemical process has been evaluated after high temperature annealing in ultra high vacuum. The decomposition of ozone in water produces a number of oxidizing species, however, despite long exposure times to the aqueous-ozone environment, no graphene oxide was observed after the two-step process. The systems were comprehensively characterized before and after processing using Raman spectroscopy, core level photoemission spectroscopy, and angle resolved photoemission spectroscopy together with low energy electron diffraction, low energy electron microscopy, and atomic force microscopy. In spite of the chemical potential of the aqueous-ozone reaction environment, the graphene domains were largely unaffected raising the prospect of employing such simple chemical and annealing protocols to clean or prepare epitaxial graphene surfaces.

Webb, Matthew J., E-mail: matthew.webb@cantab.net; Lundstedt, Anna; Grennberg, Helena [Department of Chemistry—BMC, Uppsala University, Box 576, SE-751 23 Uppsala (Sweden); Polley, Craig; Niu, Yuran; Zakharov, Alexei A.; Balasubramanian, Thiagarajan [MAX IV Laboratory, Lund University, 22100 Lund (Sweden); Dirscherl, Kai [DFM—Danish Fundamental Metrology, Matematiktorvet 307, DK-2800 Lyngby (Denmark); Burwell, Gregory; Guy, Owen J. [College of Engineering, Faraday Tower, Singleton Park, Swansea University, Swansea SA2 8PP (United Kingdom); Palmgren, Pål [VG Scienta Scientific AB, Box 15120, Vallongatan 1, SE-750 15 Uppsala (Sweden); Yakimova, Rositsa [Department of Physics, Chemistry, and Biology, Linköping University, SE-581 83 Linköping (Sweden)

2014-08-25T23:59:59.000Z

89

Ultrafast Optical Excitation of a Persistent Surface-State Population in the Topological Insulator Bi2Se3  

SciTech Connect (OSTI)

Using femtosecond time- and angle-resolved photoemission spectroscopy, we investigated the nonequilibrium dynamics of the topological insulator Bi{sub 2}Se{sub 3}. We studied p-type Bi{sub 2}Se{sub 3}, in which the metallic Dirac surface state and bulk conduction bands are unoccupied. Optical excitation leads to a meta-stable population at the bulk conduction band edge, which feeds a nonequilibrium population of the surface state persisting for >10 ps. This unusually long-lived population of a metallic Dirac surface state with spin texture may present a channel in which to drive transient spin-polarized currents.

Sobota, Jonathan

2012-03-14T23:59:59.000Z

90

Nearly Perfect Fluidity in a High Temperature Superconductor  

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

Perfect fluids are characterized as having the smallest ratio of shear viscosity to entropy density, ?/s, consistent with quantum uncertainty and causality. So far, nearly perfect fluids have only been observed in the quark-gluon plasma and in unitary atomic Fermi gases, exotic systems that are amongst the hottest and coldest objects in the known universe, respectively. We use angle resolved photoemission spectroscopy to measure the temperature dependence of an electronic analog of ?/s in an optimally doped cuprate high-temperature superconductor, finding it too is a nearly perfect fluid around, and above, its superconducting transition temperature Tc.

Rameau, J. D. [Brookhaven National Laboratory (BNL), Upton, NY (United States); Reber, T. J. [Brookhaven National Laboratory (BNL), Upton, NY (United States); Yang, H. -B. [Brookhaven National Laboratory (BNL), Upton, NY (United States); Akhanjee, S. [Brookhaven National Laboratory (BNL), Upton, NY (United States); Gu, G. D. [Brookhaven National Laboratory (BNL), Upton, NY (United States); Johnson, P. D. [Brookhaven National Laboratory (BNL), Upton, NY (United States); Campbell, S. [Iowa State University, Ames, IA (United States)

2014-10-01T23:59:59.000Z

91

Electronic Instability in a Zero-Gap Semiconductor: The Charge-Density Wave in (TaSe4)2I  

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

We report a comprehensive study of the paradigmatic quasi-1D compound (TaSe4)2I performed by means of angle-resolved photoemission spectroscopy (ARPES) and first-principles electronic structure calculations. We find it to be a zero-gap semiconductor in the nondistorted structure, with non-negligible interchain coupling. Theory and experiment support a Peierls-like scenario for the charge-density wave formation below TCDW=263??K, where the incommensurability is a direct consequence of the finite interchain coupling. The formation of small polarons, strongly suggested by the ARPES data, explains the puzzling semiconductor-to-semiconductor transition observed in transport at TCDW.

Tournier-Colletta, C.; Moreschini, L.; Autès, G.; Moser, S.; Crepaldi, A.; Berger, H.; Walter, A. L.; Kim, K. S.; Bostwick, A.; Monceau, P.; Rotenberg, E.; Yazyev, O. V.; Grioni, M.

2013-06-01T23:59:59.000Z

92

Quasi-Freestanding multilayer graphene films on the carbon face of SiC  

SciTech Connect (OSTI)

The electronic band structure of as-grown and doped graphene grown on the carbon face of SiC is studied by high-resolution angle-resolved photoemission spectroscopy, where we observe both rotations between adjacent layers and AB-stacking. The band structure of quasi-freestanding AB-bilayers is directly compared with bilayer graphene grown on the Si-face of SiC to study the impact of the substrate on the electronic properties of epitaxial graphene. Our results show that the C-face films are nearly freestanding from an electronic point of view, due to the rotations between graphene layers.

Siegel, D. A.; Hwang, C. G.; Fedorov, A. V.; Lanzara, A.

2010-06-30T23:59:59.000Z

93

EMSL - spectroscopy  

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

spectroscopy en Behavior of nanoceria in biologically-relevant environments. http:www.emsl.pnl.govemslwebpublicationsbehavior-nanoceria-biologically-relevant-environments

94

Solar energy conversion via hot electron internal photoemission in metallic nanostructures: Efficiency estimates  

SciTech Connect (OSTI)

Collection of hot electrons generated by the efficient absorption of light in metallic nanostructures, in contact with semiconductor substrates can provide a basis for the construction of solar energy-conversion devices. Herein, we evaluate theoretically the energy-conversion efficiency of systems that rely on internal photoemission processes at metal-semiconductor Schottky-barrier diodes. In this theory, the current-voltage characteristics are given by the internal photoemission yield as well as by the thermionic dark current over a varied-energy barrier height. The Fowler model, in all cases, predicts solar energy-conversion efficiencies of <1% for such systems. However, relaxation of the assumptions regarding constraints on the escape cone and momentum conservation at the interface yields solar energy-conversion efficiencies as high as 1%–10%, under some assumed (albeit optimistic) operating conditions. Under these conditions, the energy-conversion efficiency is mainly limited by the thermionic dark current, the distribution of hot electron energies, and hot-electron momentum considerations.

Leenheer, Andrew J.; Narang, Prineha; Atwater, Harry A., E-mail: haa@caltech.edu [Thomas J. Watson Laboratories of Applied Physics, California Institute of Technology, Pasadena, California 91125 (United States); Joint Center for Artificial Photosynthesis, Pasadena, California 91125 (United States); Lewis, Nathan S. [Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125 (United States); Joint Center for Artificial Photosynthesis, Pasadena, California 91125 (United States)

2014-04-07T23:59:59.000Z

95

Photoemission Spectroscopy of Magnetic and Nonmagnetic Impurities on the Surface of the Bi2Se3 Topological Insulator  

E-Print Network [OSTI]

Topological Insulator T. Valla,1,* Z.-H. Pan,1 D. Gardner,2 Y. S. Lee,2 and S. Chu3 1 Condensed Matter Physics; published 12 March 2012) Dirac-like surface states on surfaces of topological insulators have a chiral spin impurities on the surface of Bi2Se3, a model topological insulator. We reveal a remarkable insensitivity

Ohta, Shigemi

96

Er/Si (111) interface intermixing investigation using core level photoemission  

SciTech Connect (OSTI)

We present in this letter Si 2{ital p} core level photoemission measurements on the Er/Si (111) interface formed at room temperature. These spectroscopic data are compared with those measured on amorphous silicide films for various Er concentrations grown by coevaporation of Er and Si species at room temperature under ultrahigh vacuum conditions. This study reveals a strong interaction between Er and the Si (111) substrate even at very low coverage. A mixed interface is observed with silicide formation up to 6 monolayers of deposited metal which corresponds to the onset of erbium metal overgrowth. The Er concentration in the interfacial silicide is found to increase as a function of the deposited Er thickness. A model for the interface is proposed and discussed.

Haderbache, L.; Wetzel, P.; Pirri, C.; Peruchetti, J.C.; Bolmont, D.; Gewinner, G. (Laboratoire de Physique et de Spectroscopie Electronique, Faculte des Sciences et Techniques 4, rue des Freres Lumiere, 68093-Mulhouse Cedex (France))

1990-07-23T23:59:59.000Z

97

Photoemission study of the Si(111)/Gd interface: A comparison with the bulk silicides  

SciTech Connect (OSTI)

Synchrotron-radiation photoemission data from the Si(111)/Gd interface (Si 2p/Gd 4 f core levels and valence states) are compared with those from all of the silicides in the Si--Gd phase diagram (Gd/sub 3/Si/sub 5/, GdSi, Gd/sub 5/Si/sub 3/) measured in strictly comparable conditions. It is shown that the first silicide-like reaction product is formed for a Gd coverage of about 2 monolayers and that this interface silicide-like product is correlated with GdSi. These results are also discussed in connection with the Si(111)/Yb interface where the same experimental approach shows a correlation between the first silicide-like interface product and the metal-rich silicide.

Puppin, E.; Nogami, J.; Carbone, C.; Shen, Z.X.; Lindau, I.; Pate, B.B.; Abbati, I.; Braicovich, L.

1987-07-01T23:59:59.000Z

98

Photoemission rate of strongly interacting quark-gluon plasma at finite density  

SciTech Connect (OSTI)

We calculate the thermal spectral function of strongly interacting Yang-Mills plasma with finite density using the holographic technique. The gravity dual of the finite temperature and density is taken as the Reissner-Nordstroem-anti-de Sitter black hole. In the presence of charge, linearized vector modes of gravitational and electromagnetic perturbation are coupled with each other. By introducing master variables for these modes, we solve the coupled system and calculate spectral function. The spectral function gets a new peak due to the density effect, which is most dramatic in the momentum plot with fixed frequency. We also calculate the photoemission rate of our gauge theory plasma from the spectral function for lightlike momentum. AC, dc conductivity, and their density dependence is also computed.

Jo, Kwanghyun; Sin, Sang-Jin [Department of Physics, Hanyang University, Seoul 133-791 (Korea, Republic of)

2011-01-15T23:59:59.000Z

99

Enhancement of ultrafast electron photoemission from metallic nano antennas excited by a femtosecond laser pulse  

E-Print Network [OSTI]

We have demonstrated for the first time that an array of nanoantennas (central nanotips inside sub-micron pits) on an aluminum surface, fabricated using a specific double-pulse femtosecond laser irradiation scheme, results in a 28-fold enhancement of the non-linear (three-photon) electron photoemission yield, driven by a third intense IR femtosecond laser pulse. The supporting numerical electrodynamic modeling indicates that the electron emission is increased not owing to a larger effective aluminum surface, but due to instant local electromagnetic field enhancement near the nanoantenna, contributed by both the tip's lightning rod effect and the focusing effect of the pit as a microreflector and annular edge as a plasmonic lens.

Gubko, M A; Ionin, A A; Kudryashov, S I; Makarov, S V; Nathala, C S R; Rudenko, A A; Seleznev, L V; Sinitsyn, D V; Treshin, I V

2013-01-01T23:59:59.000Z

100

Femtosecond time-resolved photoemission electron microscopy for spatiotemporal imaging of photogenerated carrier dynamics in semiconductors  

SciTech Connect (OSTI)

We constructed an instrument for time-resolved photoemission electron microscopy (TR-PEEM) utilizing femtosecond (fs) laser pulses to visualize the dynamics of photogenerated electrons in semiconductors on ultrasmall and ultrafast scales. The spatial distribution of the excited electrons and their relaxation and/or recombination processes were imaged by the proposed TR-PEEM method with a spatial resolution about 100 nm and an ultrafast temporal resolution defined by the cross-correlation of the fs laser pulses (240 fs). A direct observation of the dynamical behavior of electrons on higher resistivity samples, such as semiconductors, by TR-PEEM has still been facing difficulties because of space and/or sample charging effects originating from the high photon flux of the ultrashort pulsed laser utilized for the photoemission process. Here, a regenerative amplified fs laser with a widely tunable repetition rate has been utilized, and with careful optimization of laser parameters, such as fluence and repetition rate, and consideration for carrier lifetimes, the electron dynamics in semiconductors were visualized. For demonstrating our newly developed TR-PEEM method, the photogenerated carrier lifetimes around a nanoscale defect on a GaAs surface were observed. The obtained lifetimes were on a sub-picosecond time scale, which is much shorter than the lifetimes of carriers observed in the non-defective surrounding regions. Our findings are consistent with the fact that structural defects induce mid-gap states in the forbidden band, and that the electrons captured in these states promptly relax into the ground state.

Fukumoto, Keiki, E-mail: fukumoto.k.ab@m.titech.ac.jp; Yamada, Yuki; Matsuki, Takashi; Koshihara, Shin-ya [Department of Materials Science, Tokyo Institute of Technology, Oookayama, Meguro-ku, Tokyo 152-8550 (Japan); Japan Science and Technology Agency JST-CREST, Honcho, Kawaguchi, Saitama 332-0012 (Japan); Onda, Ken [Interactive Research Center of Science, Tokyo Institute of Technology, Nagatsuta, Midori-ku, Yokohama 226-8502 (Japan); Japan Science and Technology Agency JST-PRESTO, Honcho, Kawaguchi, Saitama 332-0012 (Japan); Mukuta, Tatsuhiko; Tanaka, Sei-ichi [Department of Materials Science, Tokyo Institute of Technology, Oookayama, Meguro-ku, Tokyo 152-8550 (Japan)

2014-08-15T23:59:59.000Z

Note: This page contains sample records for the topic "angle-resolved photoemission spectroscopy" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

E-Print Network 3.0 - angle-resolved ion tof Sample Search Results  

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

apparatus used to measure energy and angle... -of-flight (TOF) distributions of the neutral molecules are recorded by varying the delay between the ion pulse... 111 The TOF...

102

E-Print Network 3.0 - angle-resolved electron energy Sample Search...  

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

which electrons can bypass the energy gap by moving in surface states. The energy... by Hasan and Cava detected these unusual surface states in the ... Source: Petta, Jason -...

103

E-Print Network 3.0 - angle-resolved thermal conductivity Sample...  

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

single-walled carbon nanotube films Kei... , the expectation on single-walled carbon nanotubes (SWNTs) to possess high thermal conductivity has attracted... of the thermal...

104

Time-and angle-resolved emission of a microcavity in the non-linear regime  

E-Print Network [OSTI]

, France 3 Physics Dept., Swiss Federal Institute of Technology, CH-1015 Lausanne, Switzerland Abstract. We be achieved under high-energy non-resonant excitation conditions [14], because saturation of the strong,16]. On the other hand, a renewed interest on the carriers' spin in semiconductor structures has given rise to a new

Viña, Luis

105

E-Print Network 3.0 - angle-resolved optical coherence Sample...  

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

Angle ... Source: Roma "La Sapienza", Universit di - Dipartimento di Fisica, Quantum Optics Group Collection: Physics 2 Ultrafast coherent control of electric currents at metal...

106

angle-resolved hypersatellite emission: Topics by E-print Network  

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

Ru bpy 3 2+ PF6 - 2, Ru Braun, Paul 51 BP's Perspective on Emissions Purdue Emissions Trading Workshop Environmental Sciences and Ecology Websites Summary: BP's Perspective...

107

angle-resolving electron spectrometer: Topics by E-print Network  

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

(HRS). We detail the computation method and the inputs used. The main result is that the aerogel Cerenkov counter provides almost 40 % of the total production of delta-electrons....

108

E-Print Network 3.0 - angle resolved xps Sample Search Results  

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

Ir clusters on TiO2 Summary: . Over a wide range of impact energies, both Ir XPS intensity and peak position are constant, indicating... , comparison of ISS and XPS data show...

109

E-Print Network 3.0 - angle resolved photoelectron Sample Search...  

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

energy and CEP. Although the individual multiphoton transition rates depend on the intensity... profile of the pulse, the experimentally measured photoelectron angular...

110

E-Print Network 3.0 - angle resolved thermal Sample Search Results  

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

2 3 4 5 > >> 41 Inverse Problems IO (19941 185-197. Printed in the UK Thermal-wave slice tomography using wave-field Summary: Inverse Problems IO (19941 185-197. Printed in the UK...

111

SURFACE SEGREGATION STUDIES OF SOFC CATHODES: COMBINING SOFT X-RAYS AND ELECTROCHEMICAL IMPEDENCE SPECTROSCOPY  

SciTech Connect (OSTI)

A system to grow heteroepitaxial thin-films of solid oxide fuel cell (SOFC) cathodes on single crystal substrates was developed. The cathode composition investigated was 20% strontium-doped lanthanum manganite (LSM) grown by pulsed laser deposition (PLD) on single crystal (111) yttria-stabilized zirconia (YSZ) substrates. By combining electrochemical impedance spectroscopy (EIS) with x-ray photoemission spectroscopy (XPS) and x-ray absorption spectroscopy XAS measurements, we conclude that electrically driven cation migration away from the two-phase gas-cathode interface results in improved electrochemical performance. Our results provide support to the premise that the removal of surface passivating phases containing Sr2+ and Mn2+, which readily form at elevated temperatures even in O2 atmospheric pressures, is responsible for the improved cathodic performance upon application of a bias.

Miara, Lincoln J.; Piper, L.F.J.; Davis, Jacob N.; Saraf, Laxmikant V.; Kaspar, Tiffany C.; Basu, Soumendra; Smith, K. E.; Pal, Uday B.; Gopalan, Srikanth

2010-12-01T23:59:59.000Z

112

Two-photon Photoemission of Organic Semiconductor Molecules on Ag(111)  

SciTech Connect (OSTI)

Angle- and time-resolved two-photon photoemission (2PPE) was used to study systems of organic semiconductors on Ag(111). The 2PPE studies focused on electronic behavior specific to interfaces and ultrathin films. Electron time dynamics and band dispersions were characterized for ultrathin films of a prototypical n-type planar aromatic hydrocarbon, PTCDA, and representatives from a family of p-type oligothiophenes.In PTCDA, electronic behavior was correlated with film morphology and growth modes. Within a fewmonolayers of the interface, image potential states and a LUMO+1 state were detected. The degree to which the LUMO+1 state exhibited a band mass less than a free electron mass depended on the crystallinity of the layer. Similarly, image potential states were measured to have free electron-like effective masses on ordered surfaces, and the effective masses increased with disorder within the thin film. Electron lifetimes were correlated with film growth modes, such that the lifetimes of electrons excited into systems created by layer-by-layer, amorphous film growth increased by orders of magnitude by only a few monolayers from the surface. Conversely, the decay dynamics of electrons in Stranski-Krastanov systems were limited by interaction with the exposed wetting layer, which limited the barrier to decay back into the metal.Oligothiophenes including monothiophene, quaterthiophene, and sexithiophene were deposited on Ag(111), and their electronic energy levels and effective masses were studied as a function of oligothiophene length. The energy gap between HOMO and LUMO decreased with increasing chain length, but effective mass was found to depend on domains from high- or low-temperature growth conditions rather than chain length. In addition, the geometry of the molecule on the surface, e.g., tilted or planar, substantially affected the electronic structure.

Yang, Aram; Yang, Aram

2008-05-15T23:59:59.000Z

113

Validity of the independent-particle approximation in x-ray photoemission: The exception, not the rule  

SciTech Connect (OSTI)

A combined experimental and theoretical study of argon valence photoionization illustrates the discovery of the broad lack of validity of the independent-particle approximation (IPA) for x-ray photoemission. In addition to previously known breakdowns of the IPA, which are limited to high photon energies and regions very near threshold, the observed breakdown in photoionization at intermediate energies demonstrates generally that the IPA is valid only in very restricted domains. These restrictions are expected to be relevant throughout the periodic table, with consequences for a wide variety of applications. {copyright} {ital 1999} {ital The American Physical Society}

Hansen, D.L.; Hemmers, O.; Wang, H.; Lindle, D.W. [Department of Chemistry, University of Nevada, Las Vegas, Nevada 89154-4003 (United States)] [Department of Chemistry, University of Nevada, Las Vegas, Nevada 89154-4003 (United States); Focke, P.; Sellin, I.A. [Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996-1200 (United States)] [Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996-1200 (United States); Heske, C. [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)] [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Chakraborty, H.S.; Deshmukh, P.C. [Department of Physics, Indian Institute of Technology-Madras, Chennai 600036 (India)] [Department of Physics, Indian Institute of Technology-Madras, Chennai 600036 (India); Manson, S.T. [Department of Physics and Astronomy, Georgia State University, Atlanta, Georgia 30303-3083 (United States)] [Department of Physics and Astronomy, Georgia State University, Atlanta, Georgia 30303-3083 (United States)

1999-10-01T23:59:59.000Z

114

Probing bismuth ferrite nanoparticles by hard x-ray photoemission: Anomalous occurrence of metallic bismuth  

SciTech Connect (OSTI)

We have investigated bismuth ferrite nanoparticles (?75?nm and ?155?nm) synthesized by a chemical method, using soft X-ray (1253.6?eV) and hard X-ray (3500, 5500, and 7500?eV) photoelectron spectroscopy. This provided an evidence for the variation of chemical state of bismuth in crystalline, phase pure nanoparticles. X-ray photoelectron spectroscopy analysis using Mg K? (1253.6?eV) source showed that iron and bismuth were present in both Fe{sup 3+} and Bi{sup 3+} valence states as expected for bismuth ferrite. However, hard X-ray photoelectron spectroscopy analysis of the bismuth ferrite nanoparticles using variable photon energies unexpectedly showed the presence of Bi{sup 0} valence state below the surface region, indicating that bismuth ferrite nanoparticles are chemically inhomogeneous in the radial direction. Consistently, small-angle X-ray scattering reveals a core-shell structure for these radial inhomogeneous nanoparticles.

Chaturvedi, Smita; Rajendra, Ranguwar; Ballav, Nirmalya; Kulkarni, Sulabha, E-mail: s.kulkarni@iiserpune.ac.in [Indian Institute of Science Education and Research, Dr. Homi Bhabha Road, Pune 411008 (India); Sarkar, Indranil [DESY Photon Science, Deutsches Elektronen-Synchrotron, 22607 Hamburg (Germany); Shirolkar, Mandar M. [Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China); Jeng, U-Ser; Yeh, Yi-Qi [National Synchrotron Radiation Research Center, 101, Hsin-Ann Road, Science Park, Hsinchu 3007-6, Taiwan (China)

2014-09-08T23:59:59.000Z

115

Direct observation of bias-dependence potential distribution in metal/HfO{sub 2} gate stack structures by hard x-ray photoelectron spectroscopy under device operation  

SciTech Connect (OSTI)

Although gate stack structures with high-k materials have been extensively investigated, there are some issues to be solved for the formation of high quality gate stack structures. In the present study, we employed hard x-ray photoelectron spectroscopy in operating devices. This method allows us to investigate bias dependent electronic states, while keeping device structures intact. Using this method, we have investigated electronic states and potential distribution in gate metal/HfO{sub 2} gate stack structures under device operation. Analysis of the core levels shifts as a function of the bias voltage indicated that a potential drop occurred at the Pt/HfO{sub 2} interface for a Pt/HfO{sub 2} gate structure, while a potential gradient was not observed at the Ru/HfO{sub 2} interface for a Ru/HfO{sub 2} gate structure. Angle resolved photoelectron spectroscopy revealed that a thicker SiO{sub 2} layer was formed at the Pt/HfO{sub 2} interface, indicating that the origin of potential drop at Pt/HfO{sub 2} interface is formation of the thick SiO{sub 2} layer at the interface. The formation of the thick SiO{sub 2} layer at the metal/high-k interface might concern the Fermi level pinning, which is observed in metal/high-k gate stack structures.

Yamashita, Y. [National Institute for Materials Science, Advanced Electric Materials Center, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); National Institute for Materials Science, NIMS Beamline Station at SPring-8, 1-1-1 Kôto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Yoshikawa, H.; Kobayashi, K. [National Institute for Materials Science, NIMS Beamline Station at SPring-8, 1-1-1 Kôto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Chikyo, T. [National Institute for Materials Science, Advanced Electric Materials Center, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan)

2014-01-28T23:59:59.000Z

116

Untangling the contributions of image charge and laser profile for optimal photoemission of high-brightness electron beams  

SciTech Connect (OSTI)

Using our model for the simulation of photoemission of high brightness electron beams, we investigate the virtual cathode physics and the limits to spatio-temporal and spectroscopic resolution originating from the image charge on the surface and from the profile of the exciting laser pulse. By contrasting the effect of varying surface properties (leading to expanding or pinned image charge), laser profiles (Gaussian, uniform, and elliptical), and aspect ratios (pancake- and cigar-like) under different extraction field strengths and numbers of generated electrons, we quantify the effect of these experimental parameters on macroscopic pulse properties such as emittance, brightness (4D and 6D), coherence length, and energy spread. Based on our results, we outline optimal conditions of pulse generation for ultrafast electron microscope systems that take into account constraints on the number of generated electrons and on the required time resolution.

Portman, J.; Zhang, H.; Makino, K.; Ruan, C. Y.; Berz, M.; Duxbury, P. M. [Physics and Astronomy Department, Michigan State University, East Lansing, Michigan 48824 (United States)

2014-11-07T23:59:59.000Z

117

Angle-Resolved High-Order Above-Threshold Ionization of a Molecule: Sensitive Tool for Molecular Characterization  

SciTech Connect (OSTI)

The strong-field approximation for ionization of diatomic molecules by an intense laser field is generalized to include rescattering of the ionized electron off the various centers of its molecular parent ion. The resulting spectrum and its interference structure strongly depend on the symmetry of the ground state molecular orbital. For N{sub 2}, if the laser polarization is perpendicular to the molecular axis, we observe a distinct minimum in the emission spectrum, which survives focal averaging and allows determination of, e.g., the internuclear separation. In contrast, for O{sub 2}, rescattering is absent in the same situation.

Busuladzic, M. [Medical Faculty, University of Sarajevo, Cekalusa 90, 71000 Sarajevo (Bosnia and Herzegowina); Gazibegovic-Busuladzic, A. [Faculty of Science, University of Sarajevo, Zmaja od Bosne 35, 71000 Sarajevo (Bosnia and Herzegowina); Milosevic, D. B. [Faculty of Science, University of Sarajevo, Zmaja od Bosne 35, 71000 Sarajevo (Bosnia and Herzegowina); Max-Born-Institut, Max-Born-Strasse 2a, 12489 Berlin (Germany); Becker, W. [Max-Born-Institut, Max-Born-Strasse 2a, 12489 Berlin (Germany)

2008-05-23T23:59:59.000Z

118

Dramatic changes in the electronic structure upon transition to the collapsed tetragonal phase in CaFe2As2  

SciTech Connect (OSTI)

We use angle-resolved photoemission spectroscopy and density functional theory calculations to study the electronic structure of CaFe2As2 in the collapsed tetragonal (CT) phase. This unusual phase of iron arsenic high-temperature superconductors was hard to measure as it exists only under pressure. By inducing internal strain, via the postgrowth thermal treatment of single crystals, we were able to stabilize the CT phase at ambient pressure. We find significant differences in the Fermi surface topology and band dispersion data from the more common orthorhombic-antiferromagnetic or tetragonal-paramagnetic phases, consistent with electronic structure calculations. The top of the hole bands sinks below the Fermi level, which destroys the nesting present in parent phases. The absence of nesting in this phase, along with an apparent loss of Fe magnetic moment, are now clearly experimentally correlated with the lack of superconductivity in this phase.

Dhaka, R. S. [Ames Laboratory; Jiang, Rui [Ames Laboratory; Budko, Sergey L. [Ames Laboratory; Canfield, Paul C. [Ames Laboratory; Harmon, Bruce N. [Ames Laboratory; Kaminski, Adam [Ames Laboratory; Tomic, Milan [Goethe-Universitat; Valenti, Roser [Goethe-Universitat; Lee, Yongbin [Ames Laboratory

2014-01-31T23:59:59.000Z

119

Experimental Realization of a Three-Dimensional Topological Insulator, Bi 2Te3  

SciTech Connect (OSTI)

Three-dimensional topological insulators are a new state of quantum matter with a bulk gap and odd number of relativistic Dirac fermions on the surface. By investigating the surface state of Bi{sub 2}Te{sub 3} with angle-resolved photoemission spectroscopy, we demonstrate that the surface state consists of a single nondegenerate Dirac cone. Furthermore, with appropriate hole doping, the Fermi level can be tuned to intersect only the surface states, indicating a full energy gap for the bulk states. Our results establish that Bi{sub 2}Te{sub 3} is a simple model system for the three-dimensional topological insulator with a single Dirac cone on the surface. The large bulk gap of Bi{sub 2}Te{sub 3} also points to promising potential for high-temperature spintronics applications.

Siemons, W.

2010-02-24T23:59:59.000Z

120

Single Dirac Cone Topological Surface State and Unusual Thermoelectric Property of Compounds from a New Topological Insulator Family  

SciTech Connect (OSTI)

Angle resolved photoemission spectroscopy (ARPES) study on TlBiTe2 and TlBiSe2 from a Thallium-based III-V-VI2 ternary chalcogenides family revealed a single surface Dirac cone at the center of the Brillouin zone for both compounds. For TlBiSe{sub 2}, the large bulk gap ({approx} 200meV) makes it a topological insulator with better mechanical properties than the previous binary 3D topological insualtor family. For TlBiTe{sub 2}, the observed negative bulk gap indicates it as a semi-metal, rather than a narrow gap semi-conductor as conventionally believed; this semi-metality naturally explains its mysteriously small thermoelectric figure of merit comparing to other compounds in the family. Finally, the unique band structures of TlBiTe{sub 2} also suggests it as a candidate for topological superconductors.

Chen, Y

2011-08-18T23:59:59.000Z

Note: This page contains sample records for the topic "angle-resolved photoemission spectroscopy" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Are cobaltates conventional? An ARPES viewpoint  

SciTech Connect (OSTI)

Recently discovered class of cobaltate superconductors (Na{sub 0.3}CoO{sub 2}.nH{sub 2}O) is a novel realization of interacting quantum electron system in a triangular network with low-energy degrees of freedom. We employ angle-resolved photoemission spectroscopy to study the quasiparticle parameters in the parent superconductors. Results reveal a large hole-like Fermi surface generated by the crossing of heavy quasiparticles. The measured quasiparticle parameters collectively suggest two orders of magnitude departure from the conventional weak coupling (such as Al) Bardeen-Cooper-Schrieffer electron dynamics paradigm and unveils cobaltates as a rather hidden class of relatively high temperature superconductors. These parameters also form the basis for a microscopic Hamiltonian of the system.

Hasan, M.Z. [Department of Physics, Joseph Henry Laboratories, Princeton University, Princeton, NJ 08544 (United States)]. E-mail: mzhasan@Princeton.edu; Qian, D. [Department of Physics, Joseph Henry Laboratories, Princeton University, Princeton, NJ 08544 (United States); Foo, M.L. [Department of Chemistry, Princeton University, Princeton, NJ 08544 (United States); Cava, R.J. [Department of Chemistry, Princeton University, Princeton, NJ 08544 (United States)

2006-07-15T23:59:59.000Z

122

Effects of Out-of-Plane Disorder on the Nodal Quasiparticle and Superconducting Gap in Single-Layer Bi_2Sr_1.6Ln_0.4CuO_6 delta (Ln = La, Nd, Gd)  

SciTech Connect (OSTI)

How out-of-plane disorder affects the electronic structure has been investigated for the single-layer cuprates Bi{sub 2}Sr{sub 1.6}Ln{sub 0.4}CuO{sub 6+{delta}} (Ln = La, Nd, Gd) by angle-resolved photoemission spectroscopy. We have observed that, with increasing disorder, while the Fermi surface shape and band dispersions are not affected, the quasi-particle width increases, the anti-nodal gap is enhanced and the superconducting gap in the nodal region is depressed. The results indicate that the superconductivity is significantly depressed by out-of-plane disorder through the enhancement of the anti-nodal gap and the depression of the superconducting gap in the nodal region.

Hashimoto, M.

2011-01-04T23:59:59.000Z

123

Many-body interactions in quasi-freestanding graphene  

SciTech Connect (OSTI)

The Landau-Fermi liquid picture for quasiparticles assumes that charge carriers are dressed by many-body interactions, forming one of the fundamental theories of solids. Whether this picture still holds for a semimetal such as graphene at the neutrality point, i.e., when the chemical potential coincides with the Dirac point energy, is one of the long-standing puzzles in this field. Here we present such a study in quasi-freestanding graphene by using high-resolution angle-resolved photoemission spectroscopy. We see the electron-electron and electron-phonon interactions go through substantial changes when the semimetallic regime is approached, including renormalizations due to strong electron-electron interactions with similarities to marginal Fermi liquid behavior. These findings set a new benchmark in our understanding of many-body physics in graphene and a variety of novel materials with Dirac fermions.

Siegel, David; Park, Cheol-Hwan; Hwang, Choongyu; Deslippe, Jack; Fedorov, Alexei; Louie, Steven; Lanzara, Alessandra

2011-06-03T23:59:59.000Z

124

Atomic and electronic structures of single-layer FeSe on SrTiO3(001): The role of oxygen deficiency  

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

Using first-principles calculation, we propose an interface structure for single triple-layer FeSe on the SrTiO3(001) surface, a high-Tc superconductor found recently. The key component of this structure is the oxygen deficiency on the top layer of the SrTiO3 substrate, as a result of Se etching used in preparing the high-Tc samples. The O vacancies strongly bind the FeSe triple layer to the substrate giving rise to a (2×1) reconstruction, as observed by scanning tunneling microscopy. The enhanced binding correlates to the significant increase of Tc observed in experiment. The O vacancies also serve as the source of electron doping, which modifies the Fermi surface of the first FeSe layer by filling the hole pocket near the center of the surface Brillouin zone, as suggested from angle-resolved photoemission spectroscopy measurement.

Bang, Junhyeok; Li, Zhi; Sun, Y. Y.; Samanta, Amit; Zhang, Y. Y.; Zhang, Wenhao; Wang, Lili; Chen, X.; Ma, Xucun; Xue, Q.-K.; Zhang, S. B.

2013-06-01T23:59:59.000Z

125

Photoemission Spectroscopy of Magnetic and Nonmagnetic Impurities on the Surface of the Bi[subscript 2]Se[subscript 3] Topological Insulator  

E-Print Network [OSTI]

Dirac-like surface states on surfaces of topological insulators have a chiral spin structure that suppresses backscattering and protects the coherence of these states in the presence of nonmagnetic scatterers. In contrast, ...

Valla, T.

126

Construction of the Magnetic Phase Diagram of FeMn/Ni/Cu(001) Using Photoemission Electron Microscopy  

SciTech Connect (OSTI)

Single crystalline FeMn/Ni bilayer was epitaxially grown on Cu(001) substrate and investigated by photoemission electron microscopy (PEEM). The FeMn and Ni films were grown into two cross wedges to facilitate an independent control of the FeMn (0-20 ML) and Ni (0-20 ML) film thicknesses. The Ni magnetic phases were determined by Ni domain images as a function of the Ni thickness (d{sub Ni}) and the FeMn thickness (d{sub FeMn}). The result shows that as the Ni thickness increases, the Ni film undergoes a paramagnetic-to-ferromagnetic state transition at a critical thickness of d{sub FM} and an in-plane to out-of-plane spin reorientation transition at a thicker thickness d{sub SRT}. The phase diagram shows that both d{sub FM} and d{sub SRT} increase as the FeMn film establishes its antiferromagnetic order.

Wu, J.; Scholl, A.; Arenholz, E.; Hwang, C.; Qiu, Z. Q.

2011-01-04T23:59:59.000Z

127

Doping of a one-dimensional Mott insulator: Photoemission and optical studies of Sr2CuO3+ T. E. Kidd,1,2,* T. Valla,1 P. D. Johnson,1 K. W. Kim,1,3 G. D. Gu,1 and C. C. Homes1  

E-Print Network [OSTI]

of spinon and holon branches in the photoemission spectra. Optical studies reveal no significant doping dependence, while photoemission studies show a large energy shift in the spinon and holon states with respect spinons or charge without spin holons .3 If created in such a system, a physical electron or hole decays

Homes, Christopher C.

128

A revolutionary rotatable electron energy analyzer for advanced high-resolution spin-polarized photoemission studies. Final Report  

SciTech Connect (OSTI)

This report details the construction and testing of a unique analyzer for spin-polarized photoemission studies of magnetic materials. This report details the progress of this project for the period from 9/1/96 through 8/31/99. Progress can be divided into two distinct areas. These are the fabrication, construction, and initial testing of the instrumentation, and the concurrent program of preliminary investigations into materials and experiments appropriate for future studies using the instrumentation developed. The analyzer complete with special input electron optics and Mott detector has been assembled in a special design UHV chamber equipped with all the capabilities needed to perform the described programs of research. These include a sophisticated five motorized axis sample manipulator with low and high temperature capability and rapid temperature cycling (acquired in collaboration with Dr. J.G. Tobin of LLNL), vacuum leak detection and gauging, in situ thin film growth instrumentation, and sample cleaning and magnetizing capabilities, The initial testing of the analyzer has been completed with successful data acquisition using both the multichannel detector mode, and spin-dependent using the Mott detector channeltrons. The data collected using the Mott detector were not truly spin dependent (see below), but demonstrate the operation of the lens and detector design. Acquisition of truly spin-dependent data await use of the EPU. Preliminary indications suggest that the analyzer performs at or above the original design parameters. In the second area of progress, we have conducted a number of preliminary studies toward the ends of identifying appropriate initial systems for investigation, and to further explore new experiments that the new instrumentation will help to pioneer. More detailed descriptions of all of these advances are given.

Waddill, G. D.; Willis, R. F.

1999-10-01T23:59:59.000Z

129

Charmonium spectroscopy, 1987  

SciTech Connect (OSTI)

The state of charmonium spectroscopy is reviewed. All analyses proceed from a spin-dependent, non-relativistic Schroedinger equation. Many of the possible branching ratios for charm like states are investigated. 17 refs.

Cahn, R.N.

1987-07-30T23:59:59.000Z

130

Toward pure electronic spectroscopy  

E-Print Network [OSTI]

In this thesis is summarized the progress toward completing our understanding of the Rydberg system of CaF and developing Pure Electronic Spectroscopy. The Rydberg system of CaF possesses a paradigmatic character due to ...

Petrovi?, Vladimir, 1978-

2009-01-01T23:59:59.000Z

131

Electronic Spectroscopy & Dynamics  

SciTech Connect (OSTI)

The Gordon Research Conference (GRC) on Electronic Spectroscopy and Dynamics was held at Colby College, Waterville, NH from 07/19/2009 thru 07/24/2009. The Conference was well-attended with participants (attendees list attached). The attendees represented the spectrum of endeavor in this field coming from academia, industry, and government laboratories, both U.S. and foreign scientists, senior researchers, young investigators, and students. The GRC on Electronic Spectroscopy & Dynamics showcases some of the most recent experimental and theoretical developments in electronic spectroscopy that probes the structure and dynamics of isolated molecules, molecules embedded in clusters and condensed phases, and bulk materials. Electronic spectroscopy is an important tool in many fields of research, and this GRC brings together experts having diverse backgrounds in physics, chemistry, biophysics, and materials science, making the meeting an excellent opportunity for the interdisciplinary exchange of ideas and techniques. Topics covered in this GRC include high-resolution spectroscopy, biological molecules in the gas phase, electronic structure theory for excited states, multi-chromophore and single-molecule spectroscopies, and excited state dynamics in chemical and biological systems.

Mark Maroncelli, Nancy Ryan Gray

2010-06-08T23:59:59.000Z

132

Plasmon Enhanced Photoemission  

E-Print Network [OSTI]

64 IPA Isopropylan isopropyl alcohol (IPA) : DI water solution in 7 : 3minutes 4. Clean the wafer with IPA and dry with nitrogen If

Polyakov, Aleksandr

2013-01-01T23:59:59.000Z

133

Plasmon Enhanced Photoemission  

E-Print Network [OSTI]

64 IPA Isopropylan isopropyl alcohol (IPA) : DI water solution in 7 : 3minutes 4. Clean the wafer with IPA and dry with nitrogen If

Polyakov, Aleksandr N.

2012-01-01T23:59:59.000Z

134

Photoemission Electron Microscope | EMSL  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassive Solar Home Design Passive SolarCenter | Argonne-Northwestern

135

Fourier Transform Infrared Spectroscopy  

E-Print Network [OSTI]

FTIR - 1 Fourier Transform Infrared Spectroscopy FTIR DETERMINATION OF MTBE IN GASOLINE AND ETHANOL FTIR DETERMINATION OF MTBE IN GASOLINE AND ETHANOL IN VODKA AND MOUTHWASH INTRODUCTION As a part has contained MTBE (methyl tert­butyl ether) as its primary oxygenate. However, there has been

Nizkorodov, Sergey

136

X-ray absorption spectroscopy  

E-Print Network [OSTI]

009-9473-8 REVIEW X-ray absorption spectroscopy Junko Yano Æand application of X-ray absorption spectroscopy, bothX-ray absorption near-edge structure (XANES) and extended X-

Yano, Junko; Yachandra, Vittal K.

2009-01-01T23:59:59.000Z

137

X-ray Absorption Spectroscopy  

E-Print Network [OSTI]

type: Review X-ray Absorption Spectroscopy Junko Yano andPhotosystem II; XAS, X-ray absorption spectroscopy; EXAFS,X-ray absorption fine structure; EPR, electron paramagnetic

Yano, Junko

2010-01-01T23:59:59.000Z

138

Laser-Induced Breakdown Spectroscopy  

E-Print Network [OSTI]

LIBS-1 Laser-Induced Breakdown Spectroscopy LIBS ANALYSIS OF METAL SURFACES Last updated: June 17, 2014 #12;LIBS-2 Laser­Induced Breakdown Spectroscopy (LIBS) LIBS ANALYSIS OF METAL SURFACES of species at a distance or in hard­to­reach or hazardous environments. Laser­Induced Breakdown Spectroscopy

Nizkorodov, Sergey

139

(Resonance ionization spectroscopy)  

SciTech Connect (OSTI)

J. P. Young attended the Fifth International Symposium on Resonance Ionization Spectroscopy and presented an invited oral presentation on research he and coworkers had carried out in applying diode lasers to resonance ionization mass spectrometry. A summary of the conference is given along with an assessment of some of the presentations that the author found of interest. Young also visited Professor Marassi at the University of Camerino to present a seminar and discuss mutual interests in a new molten salt research project of the author. Some of the studies at Camerino are described. Ideas concerning the author's research that came from private discussions are also presented here.

Young, J.P.

1990-10-11T23:59:59.000Z

140

Spectroscopy and Diffraction | EMSL  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation Desert Southwest RegionatSearchScheduled System Highlights Power2014 EvaluateSpectroscopy and

Note: This page contains sample records for the topic "angle-resolved photoemission spectroscopy" from the National Library of EnergyBeta (NLEBeta).
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141

Spectroscopy of semiconductor materials  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassiveSubmittedStatus Tom Fletcher,Future |CarlosSpeakersSpectroscopy Print

142

The light meson spectroscopy program  

SciTech Connect (OSTI)

Recent discoveries of a number of unexpected new charmomium-like meson states at the BaBar and Belle B-factories have demonstrated how little is still known about meson spectroscopy. In this talk we will review recent highlights of the light quark spectroscopy from collider and fixed target experiments.

Smith, Elton S. [JLAB

2014-06-01T23:59:59.000Z

143

Solar Spectroscopy at ARIES  

E-Print Network [OSTI]

Identification of Fraunhofer lines with the known atomic and molecular absorbers and predictions leading to such an effort has been a challenging area of study crowned with occasional success. Such studies have also lead, amongst other things to (i) a determination of abundances of elements and that of their isotopes (ii) valuable information on model atmospheres and (iii) use of Sun as a laboratory source. We summarize and review here the work done in the last four decades in the area of solar spectroscopy at Aryabhatta Research Institute of observational sciencES (ARIES in short) with a view to pick up new and interesting areas for future investigations in the light of the tremendous progress made elsewhere in observations of the sun and in the laboratory studies.

K. Sinha

2006-10-10T23:59:59.000Z

144

Nitrogen doping of chemical vapor deposition grown graphene on 4H-SiC (0001)  

SciTech Connect (OSTI)

We present optical, electrical, and structural properties of nitrogen-doped graphene grown on the Si face of 4H-SiC (0001) by chemical vapor deposition method using propane as the carbon precursor and N{sub 2} as the nitrogen source. The incorporation of nitrogen in the carbon lattice was confirmed by X-ray photoelectron spectroscopy. Angle-resolved photoemission spectroscopy shows carrier behavior characteristic for massless Dirac fermions and confirms the presence of a graphene monolayer in the investigated nitrogen-doped samples. The structural and electronic properties of the material were investigated by Raman spectroscopy. A systematical analysis of the graphene Raman spectra, including D, G, and 2D bands, was performed. In the case of nitrogen-doped samples, an electron concentration on the order of 5–10 × 10{sup 12}?cm{sup ?2} was estimated based upon Raman and Hall effect measurements and no clear dependence of the carrier concentration on nitrogen concentration used during growth was observed. This high electron concentration can be interpreted as both due to the presence of nitrogen in graphitic-like positions of the graphene lattice as well as to the interaction with the substrate. A greater intensity of the Raman D band and increased inhomogeneity, as well as decreased electron mobility, observed for nitrogen-doped samples, indicate the formation of defects and a modification of the growth process induced by nitrogen doping.

Urban, J. M.; Binder, J.; Wysmo?ek, A. [Faculty of Physics, University of Warsaw, ul. Ho?a 69, 00-681 Warsaw (Poland); D?browski, P.; Strupi?ski, W. [Institute of Electronic Materials Technology, ul. Wólczy?ska 133, 01-919 Warsaw (Poland); Kopciuszy?ski, M.; Ja?ochowski, M. [Institute of Physics, Maria Curie-Sk?odowska University, pl. M. Curie-Sk?odowskiej 1, 20-031 Lublin (Poland); Klusek, Z. [Faculty of Physics and Applied Informatics, University of ?ód?, ul. Pomorska 149/153, 90-236 ?ód? (Poland); Baranowski, J. M. [Faculty of Physics, University of Warsaw, ul. Ho?a 69, 00-681 Warsaw (Poland); Institute of Electronic Materials Technology, ul. Wólczy?ska 133, 01-919 Warsaw (Poland)

2014-06-21T23:59:59.000Z

145

Sum Frequency Generation for Surface Vibrational Spectroscopy...  

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

Sum Frequency Generation for Surface Vibrational Spectroscopy Sum Frequency Generation for Surface Vibrational Spectroscopy This customized SFG-VS spectrometer incorporates unique...

146

Ring resonant cavities for spectroscopy  

DOE Patents [OSTI]

Ring-shaped resonant cavities for spectroscopy allow a reduction in optical feedback to the light source, and provide information on the interaction of both s- and p-polarized light with samples. A laser light source is locked to a single cavity mode. An intracavity acousto-optic modulator may be used to couple light into the cavity. The cavity geometry is particularly useful for Cavity Ring-Down Spectroscopy (CRDS). 6 figs.

Zare, R.N.; Martin, J.; Paldus, B.A.; Xie, J.

1999-06-15T23:59:59.000Z

147

Transient Absorption Spectroscopy with Isolated Attosecond Pulses  

E-Print Network [OSTI]

viii Attosecond transient absorption instrument. . . . . .5.2.2 AbsorptionTransient absorption spectroscopy . . . . . . . . . . . .

Bell, Marie Justine

2013-01-01T23:59:59.000Z

148

TIME-RESOLVED VIBRATIONAL SPECTROSCOPY  

SciTech Connect (OSTI)

This document contains the Proceedings from the 14th International Conference on Time-Resolved Vibrational Spectroscopy, which was held in Meredith, NH from May 9-14, 2009. The study of molecular dynamics in chemical reaction and biological processes using time-resolved spectroscopy plays an important role in our understanding of energy conversion, storage, and utilization problems. Fundamental studies of chemical reactivity, molecular rearrangements, and charge transport are broadly supported by the DOE�s Office of Science because of their role in the development of alternative energy sources, the understanding of biological energy conversion processes, the efficient utilization of existing energy resources, and the mitigation of reactive intermediates in radiation chemistry. In addition, time-resolved spectroscopy is central to all five of DOE�s grand challenges for fundamental energy science. The Time-Resolved Vibrational Spectroscopy conference is organized biennially to bring the leaders in this field from around the globe together with young scientists to discuss the most recent scientific and technological advances. The latest technology in ultrafast infrared, Raman, and terahertz spectroscopy and the scientific advances that these methods enable were covered. Particular emphasis was placed on new experimental methods used to probe molecular dynamics in liquids, solids, interfaces, nanostructured materials, and biomolecules.

Andrei Tokmakoff, MIT (Conference Chair) [Conference Chair; Paul Champion, Northeastern University; Edwin J. Heilweil, NIST; Keith A. Nelson, MIT; Larry Ziegler, Boston University

2009-05-14T23:59:59.000Z

149

Superconducting order parameter in nonmagnetic borocarbides RNi?B?C (R=Y, Lu) probed by point-contact Andreev reflection spectroscopy  

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

We report on the measurements of the superconducting order parameter in the nonmagnetic borocarbides LuNi?B?C and YNi?B?C. Andreev conductance spectra are obtained from nanoscale metallic junctions on single crystal surfaces prepared along three major crystallographic orientations: [001], [110], and [100]. The gap values extracted by the single-gap Blonder-Tinkham-Klapwijk model follow the theoretical predictions as a function of temperature and magnetic field and exhibit a small anisotropy with no indication of proposed gap nodes along the [100] and [010] directions. These observations are robust and reproducible among all the measurements on two different sets of LuNi?B?C crystals and one set of YNi?B?C crystals. We suggest that the possible gap nodes in the [100] direction may be masked by two effects: different gap anisotropy across multiple Fermi surfaces, as reported in the recent photoemission spectroscopy, and the large tunneling cone. Our results provide a consistent picture of the superconducting gap structure in these materials, addressing the controversy particularly in the reported results of point-contact Andreev reflection spectroscopy.

Lu, X.; Park, W. K.; Yeo, S.; Oh, K.-H.; Lee, S.-I.; Bud’ko, S. L.; Canfield, P. C.; Greene, L. H.

2011-03-01T23:59:59.000Z

150

Scientific innovation and resonance ionization spectroscopy  

SciTech Connect (OSTI)

An account is presented of the development and appliations of resonance ionization spectroscopy and one atom detection.

Richmond, C.R.

1981-01-01T23:59:59.000Z

151

Material and Doping Dependence of the Nodal and Anti-Nodal Dispersion Renormalizations in Single- and Multi-Layer Cuprates  

SciTech Connect (OSTI)

In this paper we present a review of bosonic renormalization effects on electronic carriers observed from angle-resolved photoemission spectra in the cuprates. Specifically, we discuss the viewpoint that these renormalizations represent coupling of the electrons to the lattice and review how materials dependence, such as the number of CuO{sub 2} layers, and doping dependence can be understood straightforwardly in terms of several aspects of electron-phonon coupling in layered correlated materials.

Johnston, S.; /Waterloo U. /SLAC; Lee, W.S.; /Stanford U., Geballe Lab. /SLAC; Nowadnick, E.A.; /SLAC /Stanford U., Phys. Dept.; Moritz, B.; /SLAC /North Dakota U.; Shen, Z.-X.; /Stanford U., Geballe Lab. /SLAC /Stanford U., Phys. Dept. /Stanford U., Appl. Phys. Dept.; Devereaux, T.P.; /Stanford U., Geballe Lab. /SLAC

2010-02-15T23:59:59.000Z

152

Fermion correlators in non-abelian holographic superconductors  

E-Print Network [OSTI]

We consider fermion correlators in non-abelian holographic superconductors. The spectral function of the fermions exhibits several interesting features such as support in displaced Dirac cones and an asymmetric distribution of normal modes. These features are compared to similar ones observed in angle resolved photoemission experiments on high T_c superconductors. Along the way we elucidate some properties of p-wave superconductors in AdS_4 and discuss the construction of SO(4) superconductors.

Steven S. Gubser; Fabio D. Rocha; Amos Yarom

2010-02-24T23:59:59.000Z

153

Stark spectroscopy on rare gas atoms  

E-Print Network [OSTI]

Stark spectroscopy on rare gas atoms PROEFSCHRIFT ter verkrijging van de graad van doctor aan de-DATA LIBRARY TECHNISCHE UNIVERSITEIT EINDHOVEN Jiang, Tao Stark spectroscopy on rare gas atoms / by Tao Jiang / gasontladingen Subject headings : plasma diagnostics / Stark effect / optogalvanic spectroscopy / atomic emission

Eindhoven, Technische Universiteit

154

X-Ray Absorption Spectroscopy of Metallobiomolecules  

E-Print Network [OSTI]

2/9/07 1 X-Ray Absorption Spectroscopy of Metallobiomolecules The Outskirts of Structural Biology 9, 07] This is a tutorial about the use of X-ray Absorption Spectroscopy (XAS) in biology, RG; Eisenberger, P; Kincaid, BM "X-ray Absorption Spectroscopy of Biological Molecules" Annu. Rev

Scott, Robert A.

155

X-Ray Absorption Spectroscopy of Metallobiomolecules  

E-Print Network [OSTI]

9/6/09 1 X-Ray Absorption Spectroscopy of Metallobiomolecules The Outskirts of Structural Biology 6, 09] This is a tutorial about the use of X-ray Absorption Spectroscopy (XAS) in biology, RG; Eisenberger, P; Kincaid, BM "X-ray Absorption Spectroscopy of Biological Molecules" Annu. Rev

Scott, Robert A.

156

Spectroscopy with Multichannel Correlation Radiometers  

E-Print Network [OSTI]

Correlation radiometers make true differential measurements in power with high accuracy and small systematic errors. This receiver architecture has been used in radio astronomy for measurements of continuum radiation for over 50 years; this article examines spectroscopy over broad bandwidths using correlation techniques. After general discussions of correlation and the choice of hybrid phase, experimental results from tests with a simple laboratory multi-channel correlation radiometer are shown. Analysis of the effect of the input hybrid's phase shows that a 90 degree hybrid is likely to be the best general choice for radio astronomy, depending on its amplitude match and phase flatness with frequency. The laboratory results verify that the combination of the correlation architecture and an analog lag correlator is an excellent method for spectroscopy over very wide bandwidths.

A. I. Harris

2005-04-20T23:59:59.000Z

157

Quantitative tunneling spectroscopy of nanocrystals  

SciTech Connect (OSTI)

The proposed goals of this collaborative work were to systematically characterize the electronic structure and dynamics of 3-dimensional metal and semiconducting nanocrystals using scanning tunneling microscopy/spectroscopy (STM/STS) and ballistic electron emission spectroscopy (BEES). This report describes progress in the spectroscopic work and in the development of methods for creating and characterizing gold nanocrystals. During the grant period, substantial effort also was devoted to the development of epitaxial graphene (EG), a very promising materials system with outstanding potential for nanometer-scale ballistic and coherent devices ("graphene" refers to one atomic layer of graphitic, sp2 -bonded carbon atoms [or more loosely, few layers]). Funding from this DOE grant was critical for the initial development of epitaxial graphene for nanoelectronics

First, Phillip N; Whetten, Robert L; Schaaff, T Gregory

2007-05-25T23:59:59.000Z

158

Light Hadron Spectroscopy and Charmonium  

E-Print Network [OSTI]

During the last few years there has been a renaissance in charm and charmonium spectroscopy with higher precision measurements at the $\\psi^{'}$ and $\\psi(3770)$ coming from BESII and CLEOc and many new discoveries coming from B-factories. In this paper, I review some new results on "classical" charmonium and $e^+ e^- \\to$ hadrons using B-factory Initial State Radiation and two photon events.

Frederick A. Harris

2008-10-17T23:59:59.000Z

159

SciTech Connect: National synchrotron light source. Activity...  

Office of Scientific and Technical Information (OSTI)

materials; time resolved spectroscopy; UV photoemission and surface science; x-ray absorption spectroscopy; x-ray scattering and crystallography; x-ray topography; the 1995 NSLS...

160

Boron Doped diamond films as electron donors in photovoltaics: An X-ray absorption and hard X-ray photoemission study  

SciTech Connect (OSTI)

Highly boron-doped diamond films are investigated for their potential as transparent electron donors in solar cells. Specifically, the valence band offset between a diamond film (as electron donor) and Cu(In,Ga)Se{sub 2} (CIGS) as light absorber is determined by a combination of soft X-ray absorption spectroscopy and hard X-ray photoelectron spectroscopy, which is more depth-penetrating than standard soft X-ray photoelectron spectroscopy. In addition, a theoretical analysis of the valence band is performed, based on GW quasiparticle band calculations. The valence band offset is found to be small: VBO?=?VBM{sub CIGS} – VBM{sub diamond}?=?0.3?eV?±?0.1?eV at the CIGS/Diamond interface and 0.0?eV?±?0.1?eV from CIGS to bulk diamond. These results provide a promising starting point for optimizing the band offset by choosing absorber materials with a slightly lower valence band maximum.

Kapilashrami, M.; Zegkinoglou, I. [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Department of Physics, University of Wisconsin Madison, Madison, Wisconsin 53706 (United States); Conti, G.; Nemšák, S.; Conlon, C. S.; Fadley, C. S. [Department of Physics, University of California, Davis, California 95616 (United States); Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Törndahl, T.; Fjällström, V. [Ångström Solar Center, Uppsala University, Box 534, SE-751 21 Uppsala (Sweden); Lischner, J. [Department of Physics, University of California, Berkeley, California 94720 (United States); Louie, Steven G. [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Department of Physics, University of California, Berkeley, California 94720 (United States); Hamers, R. J.; Zhang, L. [Department of Chemistry, University of Wisconsin Madison, Madison, Wisconsin 53706 (United States); Guo, J.-H. [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Himpsel, F. J., E-mail: fhimpsel@wisc.edu [Department of Physics, University of Wisconsin Madison, Madison, Wisconsin 53706 (United States)

2014-10-14T23:59:59.000Z

Note: This page contains sample records for the topic "angle-resolved photoemission spectroscopy" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Synchrotron radiation photoemission study of interfacial electronic structure of HfO{sub 2} on In{sub 0.53}Ga{sub 0.47}As(001)-4?×?2 from atomic layer deposition  

SciTech Connect (OSTI)

The growth of a passivating layer on a In{sub 0.53}Ga{sub 0.47}As(001)-4?×?2 surface by atomic-layer deposition of tetrakis[ethylmethylamino]Hafnium (TEMAHf)) followed by the water pulse was investigated by synchrotron radiation photoemission. The Hf atoms maintain four-fold coordination, both after the initial TEMAHf deposition and the subsequent water pulse. The Hf atoms initially bond to the As dangling bonds of the surface As atom located on the edges of the raised ridges. One EMA ligand is removed in this process. Subsequent water exposure substitutes OH ligand for one or more remaining EMA ligands. These in turn react with TEMAHf to form Hf-O-Hf bonds allowing the hafnium oxides to grow. The surface In atoms on the terrace of the raised ridges were partially removed, but none bonded of the precursor atoms. Correlations between the interfacial electronic structure and the electric performance are discussed.

Pi, T. W., E-mail: pi@nsrrc.org.tw, E-mail: gkwer@verizon.net, E-mail: raynien@phys.nthu.edu.tw, E-mail: mhong@phys.ntu.edu.tw [National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan (China); Lin, T. D.; Chang, Y. C.; Hong, M., E-mail: pi@nsrrc.org.tw, E-mail: gkwer@verizon.net, E-mail: raynien@phys.nthu.edu.tw, E-mail: mhong@phys.ntu.edu.tw [Graduate Institute of Applied Physics and Department of Physics, National Taiwan University, Taipei 10617, Taiwan (China); Lin, H. Y.; Kwo, J., E-mail: pi@nsrrc.org.tw, E-mail: gkwer@verizon.net, E-mail: raynien@phys.nthu.edu.tw, E-mail: mhong@phys.ntu.edu.tw [Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Wertheim, G. K., E-mail: pi@nsrrc.org.tw, E-mail: gkwer@verizon.net, E-mail: raynien@phys.nthu.edu.tw, E-mail: mhong@phys.ntu.edu.tw [Woodland Consulting, 175 Woodland Ave., Morristown, New Jersey 07960 (United States)

2014-01-27T23:59:59.000Z

162

Disentangling phonon and impurity interactions in ?-doped Si(001)  

SciTech Connect (OSTI)

We present a study of the phonon and impurity interactions in a shallow two dimensional electron gas formed in Si(001). A highly conductive ultra-narrow n-type dopant ?-layer, which serves as a platform for quantum computation architecture, is formed and studied by angle resolved photoemission spectroscopy (ARPES) and temperature dependent nanoscale 4-point probe (4PP). The bandstructure of the ?-layer state is both measured and simulated. At 100?K, good agreement is only achieved by including interactions; electron-impurity scattering (W{sub 0}?=?56 to 61?meV); and electron-phonon coupling (??=?0.14?±?0.04). These results are shown to be consistent with temperature dependent 4PP resistance measurements which indicate that at 100?K, ?7?8 of the measured resistance is due to impurity scattering with the remaining 1/8 coming from phonon interactions. In both resistance and bandstructure measurements, the impurity contribution exhibits a variability of ?9% for nominally identical samples. The combination of ARPES and 4PP affords a thorough insight into the relevant contributions to electrical resistance in reduced dimensionality electronic platforms.

Mazzola, Federico; Wells, Justin W., E-mail: quantum.wells@gmail.com [Department of Physics, Norwegian University of Science and Technology (NTNU), N-7491 Trondheim (Norway); Polley, Craig M. [MAX IV Laboratory, Lund University, 221 00 Lund (Sweden); School of Physics, Centre of Excellence for Quantum Computation and Communication Technology, University of New South Wales, Sydney, NSW 2052 (Australia); Miwa, Jill A. [Department of Physics and Astronomy, Interdisciplinary Nanoscience Center (iNANO), University of Aarhus, 8000 Aarhus C (Denmark); Simmons, Michelle Y. [School of Physics, Centre of Excellence for Quantum Computation and Communication Technology, University of New South Wales, Sydney, NSW 2052 (Australia)

2014-04-28T23:59:59.000Z

163

ARPES-parameterized Hubbard approach to d-wave cuprate superconductors  

SciTech Connect (OSTI)

In the last decade, the Angle Resolved Photoemission Spectroscopy (ARPES) has achieved important advances in both energy and angular resolutions, providing a direct measurement of the single-particle dispersion relation and superconducting gap. These dispersion relation data allow a full determination of the self-energy, first and second neighbor parameters in the Hubbard model. This model and its generalizations offer a simple and general way to describe the electronic correlation in solids. In particular, the parameters of correlated hopping interactions, responsible of the d-wave superconductivity in the generalized Hubbard model, are determined from ARPES data and the critical temperature within the mean-field approximation. In this work, we determine the model parameters for Bi{sub 2}Sr{sub 2?x}La{sub x}CuO{sub 6+?} and study its d-wave superconducting gap as a function of temperature by solving numerically two coupled integral equations. Finally, the calculated electronic specific heat is compared with experimental results.

Pérez, Luis A., E-mail: lperez@fisica.unam.mx [Instituto de Física, Universidad Nacional Autónoma de México, Apartado Postal 20-364, 01000 D.F. (Mexico); Galván, César G.; Wang, Chumin [Instituo de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Apartado Postal 70-360, 04510 D.F. (Mexico)

2014-01-27T23:59:59.000Z

164

Atomic and electronic structures of single-layer FeSe on SrTiO3(001): The role of oxygen deficiency  

SciTech Connect (OSTI)

Using first-principles calculation, we propose an interface structure for single triple-layer FeSe on the SrTiO3(001) surface, a high-Tc superconductor found recently. The key component of this structure is the oxygen deficiency on the top layer of the SrTiO3 substrate, as a result of Se etching used in preparing the high-Tc samples. The O vacancies strongly bind the FeSe triple layer to the substrate giving rise to a (2×1) reconstruction, as observed by scanning tunneling microscopy. The enhanced binding correlates to the significant increase of Tc observed in experiment. The O vacancies also serve as the source of electron doping, which modifies the Fermi surface of the first FeSe layer by filling the hole pocket near the center of the surface Brillouin zone, as suggested from angle-resolved photoemission spectroscopy measurement.

Bang, Junhyeok; Li, Zhi; Sun, Y. Y.; Samanta, Amit; Zhang, Y. Y.; Zhang, Wenhao; Wang, Lili; Chen, X.; Ma, Xucun; Xue, Q.-K.; Zhang, S. B.

2013-06-01T23:59:59.000Z

165

Surface electronic structure for various surface preparations of Nb-doped SrTiO{sub 3} (001)  

SciTech Connect (OSTI)

High-resolution angle-resolved photoemission spectroscopy (ARPES) was used to study the surface electronic structure of Nb-doped SrTiO{sub 3} (STO) single crystals prepared using a variety of surface preparations. ARPES measurements show that simple degreasing with subsequent anneal in vacuum is not an adequate surface preparation of STO, rather, preparations consisting of etching with buffered HF or HCl, and to a lesser extent, simple water leaching resulted in surfaces with much less disorder. A non-dispersing, mid-gap state was found ?800 meV above the top of the valence band for samples which underwent etching. This mid-gap state is not present for vacuum-annealed and water-leached samples, as well as for STO thin films grown using molecular beam epitaxy. Theoretical modeling using density functional theory suggests that this mid-gap state is not related to the SrO- and TiO{sub 2}-terminated surfaces, but rather, is due to a partial hydrogenation of the STO surface that occurs during etching.

Hatch, Richard C.; Fredrickson, Kurt D.; Choi, Miri; Lin, Chungwei; Seo, Hosung; Posadas, Agham B.; Demkov, Alexander A. [Department of Physics, The University of Texas at Austin, Austin, Texas 78712 (United States)] [Department of Physics, The University of Texas at Austin, Austin, Texas 78712 (United States)

2013-09-14T23:59:59.000Z

166

Observation of the chiral magnetic effect in ZrTe5  

E-Print Network [OSTI]

The chiral magnetic effect is the generation of electric current induced by chirality imbalance in the presence of magnetic field. It is a macroscopic manifestation of the quantum anomaly in relativistic field theory of chiral fermions (massless spin $1/2$ particles with a definite projection of spin on momentum) -- a dramatic phenomenon arising from a collective motion of particles and antiparticles in the Dirac sea. The recent discovery of Dirac semimetals with chiral quasi-particles opens a fascinating possibility to study this phenomenon in condensed matter experiments. Here we report on the first observation of chiral magnetic effect through the measurement of magneto-transport in zirconium pentatelluride, ZrTe_5. Our angle-resolved photoemission spectroscopy experiments show that this material's electronic structure is consistent with a 3D Dirac semimetal. We observe a large negative magnetoresistance when magnetic field is parallel with the current. The measured quadratic field dependence of the magnetoconductance is a clear indication of the chiral magnetic effect. The observed phenomenon stems from the effective transmutation of Dirac semimetal into a Weyl semimetal induced by the parallel electric and magnetic fields that represent a topologically nontrivial gauge field background.

Qiang Li; Dmitri E. Kharzeev; Cheng Zhang; Yuan Huang; I. Pletikosic; A. V. Fedorov; R. D. Zhong; J. A. Schneeloch; G. D. Gu; T. Valla

2014-12-19T23:59:59.000Z

167

Importance of the Fermi-surface topology to the superconducting state of the electron-doped pnictide Ba(Fe1-xCox)?As?  

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

We used angle-resolved photoemission spectroscopy and thermoelectric power to study the poorly explored, highly overdoped side of the phase diagram of Ba(Fe1-xCox)?As? high-temperature superconductor. Our data demonstrate that several Lifshitz transitions—topological changes of the Fermi surface—occur for large x. The central hole barrel changes to ellipsoids that are centered at Z at x~0.11 and subsequently disappear around x~0.2; changes in thermoelectric power occur at similar x values. Tc decreases and goes to zero around x~0.15—between the two Lifshitz transitions. Beyond x=0.2 the central pocket becomes electron-like and superconductivity does not exist. Our observations reveal the importance of the underlying Fermiology in electron-doped iron arsenides. We speculate that a likely necessary condition for superconductivity in these materials is the presence of the central hole pockets rather than nesting between central and corner pockets.

Liu, Chang; Palczewski, A. D.; Dhaka, R. S.; Kondo, Takeshi; Fernandes, R. M.; Mun, E. D.; Hodovanets, H.; Thaler, A. N.; Schmalian, J.; Bud’ko, S. L.; Canfield, P. C.; Kaminski, A.

2011-07-01T23:59:59.000Z

168

Interfacial mode coupling as the origin of the enhancement of Tc in FeSe films on SrTiO3  

SciTech Connect (OSTI)

Films of iron selenide (FeSe) one unit cell thick grown on strontium titanate (SrTiO3 or STO) substrates have recently shown superconducting energy gaps opening at temperatures close to the boiling point of liquid nitrogen (77 K), which is a record for the iron-based superconductors. The gap opening temperature usually sets the superconducting transition temperature Tc, as the gap signals the formation of Cooper pairs, the bound electron states responsible for superconductivity. To understand why Cooper pairs form at such high temperatures, we examine the role of the SrTiO3 substrate. Here we report high-resolution angle-resolved photoemission spectroscopy results that reveal an unexpected characteristic of the single-unit-cell FeSe/SrTiO3 system: shake-off bands suggesting the presence of bosonic modes, most probably oxygen optical phonons in SrTiO3, which couple to the FeSe electrons with only a small momentum transfer. Such interfacial coupling assists superconductivity in most channels, including those mediated by spin fluctuations. Our calculations suggest that this coupling is responsible for raising the superconducting gap opening temperature in single-unit-cell FeSe/SrTiO3.

Lee, J.J.; Schmitt, F.T.; Moore, R.G.; Johnston, S.; Cui, Y.-T.; Li, W.; Yi, M.; Liu, Z.K.; Hashimoto, M.; Zhang, Y.; Lu, D.H.; Devereaux, T.P.; Lee, D.-H.; Shen, Z.-X.

2014-11-12T23:59:59.000Z

169

ARPES Studies of Cuprate Fermiology: Superconductivity, Pseudogap and Quasiparticle Dynamics  

SciTech Connect (OSTI)

We present angle-resolved photoemission spectroscopy (ARPES) studies of the cuprate high-temperature superconductors which elucidate the relation between superconductivity and the pseudogap and highlight low-energy quasiparticle dynamics in the superconducting state. Our experiments suggest that the pseudogap and superconducting gap represent distinct states, which coexist below T{sub c}. Studies on Bi-2212 demonstrate that the near-nodal and near-antinodal regions behave differently as a function of temperature and doping, implying that different orders dominate in different momentum-space regions. However, the ubiquity of sharp quasiparticles all around the Fermi surface in Bi-2212 indicates that superconductivity extends into the momentum-space region dominated by the pseudogap, revealing subtlety in this dichotomy. In Bi-2201, the temperature dependence of antinodal spectra reveals particle-hole asymmetry and anomalous spectral broadening, which may constrain the explanation for the pseudogap. Recognizing that electron-boson coupling is an important aspect of cuprate physics, we close with a discussion of the multiple 'kinks' in the nodal dispersion. Understanding these may be important to establishing which excitations are important to superconductivity.

Vishik, Inna

2011-06-23T23:59:59.000Z

170

Spectroscopy  

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

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171

Spectroscopy  

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

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172

Raman spectroscopy of shocked water  

SciTech Connect (OSTI)

Raman scattering has been used extensively to study the vibrational and rotational properties of molecules under a variety of conditions. Here, interest is in the behavior of water molecules shocked to high pressures and temperatures. Behind the shock front the water molecules undergo changes in bonding and the molecules may become ionized. Raman spectroscopy can be used to determine the molecular species behind the shock front. In addition, changes in Raman spectra can yield information regarding inter- and intramolecular potentials and the temperature behind the shock front.

Holmes, N.C.; Mitchell, A.C.; Nellis, W.J.; Graham, W.B.; Walrafen, G.E.

1983-07-01T23:59:59.000Z

173

Simultaneous beta and gamma spectroscopy  

DOE Patents [OSTI]

A phoswich radiation detector for simultaneous spectroscopy of beta rays and gamma rays includes three scintillators with different decay time characteristics. Two of the three scintillators are used for beta detection and the third scintillator is used for gamma detection. A pulse induced by an interaction of radiation with the detector is digitally analyzed to classify the type of event as beta, gamma, or unknown. A pulse is classified as a beta event if the pulse originated from just the first scintillator alone or from just the first and the second scintillator. A pulse from just the third scintillator is recorded as gamma event. Other pulses are rejected as unknown events.

Farsoni, Abdollah T. (Corvallis, OR); Hamby, David M. (Corvallis, OR)

2010-03-23T23:59:59.000Z

174

VARIOUS APPLICATIONS OF ZEEMAN ATOMIC ABSORPTION SPECTROSCOPY  

E-Print Network [OSTI]

APPLICATIONS OF ZEEMAN ATOMIC ABSORPTION SPECTROSCOPYthe Zeeman effect to atomic absorption spectroscopy has beenthe Zeeman effect on atomic absorption spectrometry has been

Koizumi, Hideaki

2011-01-01T23:59:59.000Z

175

An electron paramagnetic resonance spectroscopy investigation...  

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

channel is sufficiently small. The results of an electron paramagnetic resonance (EPR) spectroscopy study of Mn and Cu adsorption on the zeolite minerals zeolite Y (large...

176

Combining Feedback Absorption Spectroscopy, Amplified Resonance...  

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

On-Board Measurement of Ammonia and Nitrous Oxide Using Feedback Absorption Laser Spectroscopy Combined with Amplified Resonance and Low Pressure Sampling Cummins...

177

Optical sensing based on wavelength modulation spectroscopy  

DOE Patents [OSTI]

Techniques, apparatus and systems for using Wavelength Modulation Spectroscopy measurements to optically monitor gas media such as gases in gas combustion chambers.

Buckley, Steven G. (Redmond, WA); Gharavi, Mohammadreza (Tehran, IR); Borchers; Marco (Berlin, DE)

2011-06-28T23:59:59.000Z

178

E-Print Network 3.0 - analytical atomic spectroscopy Sample Search...  

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

A partial sampling of these techniques includes: Absorption spectroscopy Atomic absorption... spectroscopy Atomic emission spectroscopy Atomic fluorescence...

179

E-Print Network 3.0 - atomic spectroscopy technologies Sample...  

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

A partial sampling of these techniques includes: Absorption spectroscopy Atomic absorption... spectroscopy Atomic emission spectroscopy Atomic fluorescence...

180

Gas-Phase Spectroscopy of Biomolecular  

E-Print Network [OSTI]

Gas-Phase Spectroscopy of Biomolecular Building Blocks Mattanjah S. de Vries1 and Pavel Hobza2 1, REMPI, computational chemistry, spectral hole burning, jet cooling Abstract Gas-phase spectroscopy lends. In recent years, we have seen enormous progress in the study of biomolecular building blocks in the gas

de Vries, Mattanjah S.

Note: This page contains sample records for the topic "angle-resolved photoemission spectroscopy" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

X-ray Spectroscopy of Cool Stars  

E-Print Network [OSTI]

High-resolution X-ray spectroscopy has addressed not only various topics in coronal physics of stars, but has also uncovered important features relevant for our understanding of stellar evolution and the stellar environment. I summarize recent progress in coronal X-ray spectroscopy and in particular also discuss new results from studies of X-rays from pre-main sequence stars.

M. Guedel

2006-09-11T23:59:59.000Z

182

3D Spectroscopy and the Virtual Observatory  

E-Print Network [OSTI]

Integral field, or 3D, spectroscopy is the technique of obtaining spectral information over a two-dimensional, hopefully contiguous, field of view. While there is some form of astronomical 3D spectroscopy at all wavelengths, there has been a rapid increase in interest in optical and near-infrared 3D spectroscopy. This has resulted in the deployment of a large variety of integral-field spectrographs on most of the large optical/infrared telescopes. The amount of IFU data available in observatory archives is large and growing rapidly. The complications of treating IFU data as both imaging and spectroscopy make it a special challenge for the virtual observatory. This article describes the various techniques of optical and near-infrared spectroscopy and some of the general needs and issues related to the handling of 3D data by the virtual observatory.

Bryan W. Miller

2007-08-15T23:59:59.000Z

183

Silicon Photonics for chemical sensing and spectroscopy, diagnosis and therapy  

E-Print Network [OSTI]

5.5. Single-shot atomic absorption spectroscopy of rubidium26] time-wavelength atomic absorption spectroscopy of the D5.5. Single-shot atomic absorption spectroscopy of rubidium

Hon, Kam Yan

2012-01-01T23:59:59.000Z

184

X-ray Absorption Spectroscopy of Biologically Relevant Systems  

E-Print Network [OSTI]

308, Messer, B. M. X-ray Absorption Spectroscopy of AqueousSarcosine via X-ray Absorption Spectroscopy 5.1 Introductionwith Carboxylate by X-Ray Absorption Spectroscopy of Liquid

Uejio, Janel Sunayo

2010-01-01T23:59:59.000Z

185

In-situ Transmission Electron Microscopy and Spectroscopy Studies...  

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

Transmission Electron Microscopy and Spectroscopy Studies of Interfaces in Li-ion Batteries: Challenges and In-situ Transmission Electron Microscopy and Spectroscopy Studies of...

186

Self-corrected Sensors Based On Atomic Absorption Spectroscopy...  

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

corrected Sensors Based On Atomic Absorption Spectroscopy For Atom Flux Measurements In Molecular Beam Epitaxy. Self-corrected Sensors Based On Atomic Absorption Spectroscopy For...

187

Infrared Spectroscopy and Optical Constants of Porous Amorphous...  

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

Spectroscopy and Optical Constants of Porous Amorphous Solid Water. Infrared Spectroscopy and Optical Constants of Porous Amorphous Solid Water. Abstract: Reflection-absorption...

188

Applications of pulsed EPR spectroscopy to structural studies...  

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

pulsed EPR spectroscopy to structural studies of sulfite oxidizing enzymes. Applications of pulsed EPR spectroscopy to structural studies of sulfite oxidizing enzymes. Abstract:...

189

High Resolution and Low-Temperature Photoelectron Spectroscopy...  

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

High Resolution and Low-Temperature Photoelectron Spectroscopy of an Oxygen-Linked Fullerene Dimer Dianion: C120O2-. High Resolution and Low-Temperature Photoelectron Spectroscopy...

190

Infrared near-field spectroscopy of trace explosives using an...  

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

spectroscopy of trace explosives using an external cavity quantum cascade laser. Infrared near-field spectroscopy of trace explosives using an external cavity quantum...

191

PAC spectroscopy of electronic ceramics  

SciTech Connect (OSTI)

Dilute indium dopants in cerium oxides and YBa{sub 2}Cu{sub 3}O{sub x} have been studied by{sup 111}In/Cd Perturbed Angular Correlation (PAC) spectroscopy. By controlling oxygen vacancy concentration in the cerium oxides through doping or high-temperature vacuum annealing, we have found that indium always forms a defect complex unless the sample is doped to reduce greatly the oxygen vacancy concentration. Three different vacancy-associated complexes are found with concentrations that depend on doping and oxygen stoichiometry. Another defect complex occurs in samples having negligible vacancy concentration. At low temperatures, evidence is found of interaction with an electronic hole trapped by {sup 111}Cd after the radioactive decay of the {sup 111}In parent. In YBa{sub 2}Cu{sub 3}O{sub x} the indium substitutes preferentially at the Y site but has measurable probability of substitution in at least one of the two copper sites. A symmetry change near 650 {degree}C is consistent with the well-documented orthorhombic/tetragonal transition for samples in air or oxygen.

Gardner, J.A.; Wang, Ruiping; Schwenker, R. [Oregon Univ., Eugene, OR (United States). Dept. of Physics; Evenson, W.E. [Brigham Young Univ., Provo, UT (United States). Dept. of Physics and Astronomy; Rasera, R.L. [Maryland Univ., Catonsville, MD (United States). Dept. of Physics; Sommers, J.A. [Teledyne-Wah Chang, Albany, OR (United States)

1991-12-31T23:59:59.000Z

192

PAC spectroscopy of electronic ceramics  

SciTech Connect (OSTI)

Dilute indium dopants in cerium oxides and YBa{sub 2}Cu{sub 3}O{sub x} have been studied by{sup 111}In/Cd Perturbed Angular Correlation (PAC) spectroscopy. By controlling oxygen vacancy concentration in the cerium oxides through doping or high-temperature vacuum annealing, we have found that indium always forms a defect complex unless the sample is doped to reduce greatly the oxygen vacancy concentration. Three different vacancy-associated complexes are found with concentrations that depend on doping and oxygen stoichiometry. Another defect complex occurs in samples having negligible vacancy concentration. At low temperatures, evidence is found of interaction with an electronic hole trapped by {sup 111}Cd after the radioactive decay of the {sup 111}In parent. In YBa{sub 2}Cu{sub 3}O{sub x} the indium substitutes preferentially at the Y site but has measurable probability of substitution in at least one of the two copper sites. A symmetry change near 650 {degree}C is consistent with the well-documented orthorhombic/tetragonal transition for samples in air or oxygen.

Gardner, J.A.; Wang, Ruiping; Schwenker, R. (Oregon Univ., Eugene, OR (United States). Dept. of Physics); Evenson, W.E. (Brigham Young Univ., Provo, UT (United States). Dept. of Physics and Astronomy); Rasera, R.L. (Maryland Univ., Catonsville, MD (United States). Dept. of Physics); Sommers, J.A. (Teledyne-Wah Chang, Albany, OR (United States))

1991-01-01T23:59:59.000Z

193

Laser photoelectron spectroscopy of ions  

SciTech Connect (OSTI)

This enterprise uses photoelectron spectroscopy to study the properties of negative ions and radicals. The essence of our experiment is to cross a 0.6 keV mass-selected ion beam (M{sup {minus}}) with the output of a CW laser, {Dirac h}{omega}{sub o}. The resultant detached photoelectrons with kinetic energy, KE, are energy analyzed by means of a set of electrostatic hemispherical analyzers. Analysis of the photoelectron spectra enables us to extract molecular electron affinities, vibrational frequencies and electronic splittings of the final radical, M, as well as the relative molecular geometries of ions (M{sup {minus}}) and radicals (M). We have scrutinized the two simplest nitrenes: methylnitrene (CH{sub 3}N) and phenylnitrene (C{sub 6}H{sub 5}N). By preparing the corresponding anions, CH{sub 3}N{sup {minus}} and C{sub 6}H{sub 5}N{sup {minus}}, we have studied these nitrene biradicals. Singlet methylnitrene is especially interesting since it is formally a transition state.''

Ellison, G.B.

1992-01-16T23:59:59.000Z

194

Metamaterial-Enhanced Nonlinear Terahertz Spectroscopy  

E-Print Network [OSTI]

We demonstrate large nonlinear terahertz responses in the gaps of metamaterial split ring resonators in several materials and use nonlinear THz transmission and THz-pump/THz-probe spectroscopy to study the nonlinear responses ...

Hwang, Harold Young

195

Negative Ion Photoelectron Spectroscopy Confirms the Prediction...  

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

Confirms the Prediction that (CO)5 and (CO)6 Each Has a Singlet Ground State. Negative Ion Photoelectron Spectroscopy Confirms the Prediction that (CO)5 and (CO)6 Each Has a...

196

Applying near-infrared spectroscopy (nirs)  

E-Print Network [OSTI]

investigated. A recently developed optical imaging technique called near-infrared spectroscopy (NIRS) shows promise for being an acceptable alternative to invasive imaging techniques. NIRS measures correlates of neural activity by assessing hemoglobin...

Wruck, Eric Michael

2005-08-29T23:59:59.000Z

197

Developments and advances in nonlinear terahertz spectroscopy  

E-Print Network [OSTI]

Nonlinear terahertz (THz) spectroscopy is a rapidly developing field, which is concerned with driving and observing nonlinear material responses in the THz range of the electromagnetic spectrum. In this thesis, I present ...

Brandt, Nathaniel Curran

2014-01-01T23:59:59.000Z

198

A superconducting dipole magnet for laser spectroscopy  

E-Print Network [OSTI]

A SUPERCONDUCTING DIPOLE MAGNET FOR LASER SPECTROSCOPY A Thesis by KENNETH EDWARD WAGENHAUSER Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requhements for the degree of MASTER OF SCIENCE... May 1990 Major subject: Physics A SUPERCONDUCTING DIPOLE MAGNET FOR LASER SPECTROSCOPY A thesis by KENNETH EDWARD WAGENHAUSER Approved to as to style and content by: Hans A. Schuessler (Chair of Committee) David H. Russell (Member) Glenn A...

Wagenhauser, Kenneth Edward

1990-01-01T23:59:59.000Z

199

Nuclear-spectroscopy problems studied with neutrons  

SciTech Connect (OSTI)

Nuclear spectroscopy with neutrons continues to have a major impact on the progress of nuclear science. Neutrons, being uncharged, are particularly useful for the study of low energy reactions. Recent advances in time-of-flight spectroscopy, as well as in the gamma ray spectroscopy following neutron capture, have permitted precision studies of unbound and bound nuclear levels and related phenomena. By going to new energy domains, by using polarized beams and targets, through the invention of new kinds of detectors, and through the general improvement in beam quantity and quality, new features of nuclear structure and reactions have been obtained that are not ony interesting per se but are also grist for old and new theory mills. The above technical advances have opened up new opportunities for further discoveries.

Raman, S.

1982-01-01T23:59:59.000Z

200

Spectroscopy of element 115 decay chains  

SciTech Connect (OSTI)

A high-resolution a, X-ray and -ray coincidence spectroscopy experiment was conducted at the GSI Helmholtzzentrum fu r Schwerionenforschung. Thirty correlated a-decay chains were detected following the fusion-evaporation reaction 48Ca + 243Am. The observations are consistent with previous assignments of similar decay chains to originate from element Z = 115. The data includes first candidates of fingerprinting the decay step Mt --> Bh with characteristic X rays. For the first time, precise spectroscopy allows the derivation of excitation schemes of isotopes along the decay chains starting with elements Z > 112. Comprehensive Monte-Carlo simulations accompany the data analysis. Nuclear structure models provide a first level interpretation.

Rudolph, Dirk [Lund University, Sweden; Forsberg, U. [Lund University, Sweden; Golubev, P. [Lund University, Sweden; Sarmiento, L. G. [Lund University, Sweden; Yakushev, A. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Andersson, L.-L. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Di Nitto, A. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Duehllmann, Ch. E. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Gates, J. M. [Lawrence Berkeley National Laboratory (LBNL); Gregorich, K. E. [Lawrence Berkeley National Laboratory (LBNL); Gross, Carl J [ORNL; Hessberger, F. P. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Herzberg, R.-D [University of Liverpool; Khuyagbaatar, J. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Kratz, J. V. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Rykaczewski, Krzysztof Piotr [ORNL; Schaedel, M. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Aberg, S. [Lund University, Sweden; Ackermann, D. [GSI-Hemholtzzentrum fur Schwerionenforschung, Darmstadt, Germany; Block, M. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Brand, H. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Carlsson, B. G. [Lund University, Sweden; Cox, D. [University of Liverpool; Derkx, X. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Eberhardt, K. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Even, J. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Fahlander, C. [Lund University, Sweden; Gerl, J. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Jaeger, E. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Kindler, B. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Krier, J. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Kojouharov, I. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Kurz, N. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Lommel, B. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Mistry, A. [University of Liverpool; Mokry, C. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Nitsche, H. [Lawrence Berkeley National Laboratory (LBNL); Omtvedt, J. P. [Paul Scherrer Institut, Villigen, Switzerland; Papadakis, P. [University of Liverpool; Ragnarsson, I. [Lund University, Sweden; Runke, J. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Schaffner, H. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Schausten, B. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Thoerle-Pospiech, P. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Torres, T. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Traut, T. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Trautmann, N. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Tuerler, A. [Paul Scherrer Institut, Villigen, Switzerland; Ward, A. [University of Liverpool; Ward, D. E. [Lund University, Sweden; Wiehl, N. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "angle-resolved photoemission spectroscopy" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

E-Print Network 3.0 - alpha spectroscopy system Sample Search...  

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

spectroscopy... Method: high resolution (R2 104) spectroscopy of single ZL Fraunhofer line 12;Zodiacal light... spectroscopy Zodiacal light pictures 12;Zodiacal...

202

SPECIES DETERMINATION OF ORGANOMETALLIC COMPOUNDS USING ZEEMAN ATOMIC ABSORPTION SPECTROSCOPY WITH LIQUID CHROMATOGRAPHY  

E-Print Network [OSTI]

Compounds Using Zeeman Atomic Absorption Spectroscopy WithCompounds Using Zeeman ,Atomic Absorption Spectroscopy withcapabilities of Zeeman atomic absorption spectroscopy (ZAA)

Koizumi, H.

2011-01-01T23:59:59.000Z

203

X-RAY ABSORPTION SPECTROSCOPY FOR THE CHEMICAL CHARACTERIZATION OF ATMOSPHERIC AEROSOLS  

E-Print Network [OSTI]

November 11-16 9 1979 X-RAY ABSORPTION SPECTROSCOPY FOR THEUniversity of California. ABSORPTION SPECTROSCOPY FOR THEand x-ray emission and absorption spectroscopy. The first

Jaklevic, J. M.

2011-01-01T23:59:59.000Z

204

Laser spectroscopy and dynamics of transient species  

SciTech Connect (OSTI)

The goal of this program is to study the vibrational and electronic spectra and excited state dynamics of a number of transient sulfur and oxygen species. A variety of supersonic jet techniques, as well as high resolution FT-IR and intracavity dye laser spectroscopy, have been applied to these studies.

Clouthier, D.J. [Univ. of Kentucky, Lexington (United States)

1993-12-01T23:59:59.000Z

205

Inelastic Tunneling Spectroscopy in Unconventional Superconductors  

E-Print Network [OSTI]

Inelastic Tunneling Spectroscopy in Unconventional Superconductors Molecular Vibration and Single Superconductors ­ p.1/13 #12;Old Results R.C. Jaklevic and J. Lambe, Phys. Rev. Lett. 17, 1139-1140 (1966 in Unconventional Superconductors ­ p.2/13 #12;STM observation of local inelastic mode B.C. Stipe, M.A Rezaei, and W

206

Photoassociative molecular spectroscopy for atomic radiative lifetimes.  

E-Print Network [OSTI]

very far apart, in so-called long- range molecular states, their mutual interaction is ruled by plain atomic properties. The high- resolution spectroscopic study of some molecular excited states populated by photoassociation of cold atoms (photoassociative spectroscopy) gives a good illustration of this property

Boyer, Edmond

207

Multichannel photodiode detector for ultrafast optical spectroscopy  

E-Print Network [OSTI]

Construction and characterization of a multichannel photodiode detector based on commercially available components with high signal to noise of $\\sim10^{6}$ and a rapid frame rate, suitable for time resolved femtosecond spectroscopy with high repetition femtosecond sources, is presented.

Mertelj, T; Borzda, T; Vaskivskyi, I; Pogrebna, A; Mihailovic, D

2014-01-01T23:59:59.000Z

208

Spectroscopy and decays of charm and bottom  

SciTech Connect (OSTI)

After a brief review of the quark model, we discuss our present knowledge of the spectroscopy of charm and bottom mesons and baryons. We go on to review the lifetimes, semileptonic, and purely leptonic decays of these particles. We conclude with a brief discussion B and D mixing and rare decays.

Butler, J.N.

1997-10-01T23:59:59.000Z

209

Baryon spectroscopy with CLAS at Jefferson Lab  

SciTech Connect (OSTI)

A substantial part of the experimental efforts at the experimental Hall-B of Jefferson Laboratory is dedicated to this studies of light baryon spectroscopy. In this report a general overview of the experimental capabilities in the Experimental Hall-B will be presented together with preliminary results of recent double polarization measurements and finally overall status of the program.

Eugene Pasyuk, CLAS Collaboration

2012-04-01T23:59:59.000Z

210

Results and Frontiers in Lattice Baryon Spectroscopy  

SciTech Connect (OSTI)

The Lattice Hadron Physics Collaboration (LHPC) baryon spectroscopy effort is reviewed. To date the LHPC has performed exploratory Lattice QCD calculations of the low-lying spectrum of Nucleon and Delta baryons. These calculations demonstrate the effectiveness of our method by obtaining the masses of an unprecedented number of excited states with definite quantum numbers. Future work of the project is outlined.

Bulava, John; Morningstar, Colin [Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213 (United States); Edwards, Robert; Richards, David [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States); Fleming, George [Yale University New Haven, CT 06520 (United States); Juge, K. Jimmy [Department of Physics, University of the Pacific, Stockton, CA 95211 (United States); Lichtl, Adam C. [RBRC, Brookhaven National Laboratory, Upton, NY 11973 (United States); Mathur, Nilmani [Tata Institute of Fundamental Research, Mumbai 40005 (India); Wallace, Stephen J. [University of Maryland, College Park, MD 20742 (United States)

2007-10-26T23:59:59.000Z

211

Multivariate Optical Computation for Predictive Spectroscopy  

E-Print Network [OSTI]

Multivariate Optical Computation for Predictive Spectroscopy Matthew P. Nelson, Jeffrey F. Aust, J Research Council of Canada, Ottawa, Ontario, Canada K1A 0R6 A novel optical approach to predicting chemical into the structure of a set of paired optical filters. Light passing through the paired filters produces an analog

Myrick, Michael Lenn

212

Theoretical and experimental investigation of polarization spectroscopy  

E-Print Network [OSTI]

, Sweden. Polarization spectroscopy saturation curves in the co-propagating beam geometry from the excitation of OH A ²[]?-X²[] (0,0) at the Q?(8) line for sub-atmospheric pressures have been fitted to the proposed model. The model proposed in this work...

Hanna, Sherif Fayez

2001-01-01T23:59:59.000Z

213

In-flight decay spectroscopy of exotic light nuclei  

SciTech Connect (OSTI)

In-flight-decay spectroscopy is discussed, including its advantages and disadvantages. In particular the use of in-flight-decay spectroscopy for the study of two-proton decay along isobaric multiplets in highlighted.

Charity, R. J. [Department of Chemistry, Washington University, St. Louis, Mo 63130 (United States)

2012-11-20T23:59:59.000Z

214

Depth-resolved cathodoluminescence spectroscopy of silicon supersaturated with sulfur  

E-Print Network [OSTI]

We investigate the luminescence of Si supersaturated with S (Si:S) using depth-resolved cathodoluminescence spectroscopy and secondary ion mass spectroscopy as the S concentration is varied over 2 orders of magnitude ...

Fabbri, Filippo

215

EVALUATION OF TWO-BEAM SPECTROSCOPY AS A PLASMA DIAGNOSTIC.  

E-Print Network [OSTI]

BEAM SPECTROSCOPY AS A PLASMA DIAGNOSTIC Barton. Dawes B i lSpectroscopy as a Plasma Diagnostic Barton Dawes Billardis thus a non-perturbing plasma diagnostic which is shown to

Billard, Barton Dawes

2010-01-01T23:59:59.000Z

216

Polarization- and Azimuth-Resolved Infrared Spectroscopy of Water...  

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

and Azimuth-Resolved Infrared Spectroscopy of Water on TiO2(110): Anisotropy and the Hydrogen-Bonding Network. Polarization- and Azimuth-Resolved Infrared Spectroscopy of Water on...

217

Dirac Charge Dynamcs in Graphene by Infrared Spectroscopy  

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

Dirac Charge Dynamcs in Graphene by Infrared Spectroscopy Dirac Charge Dynamcs in Graphene by Infrared Spectroscopy Print Wednesday, 29 October 2008 00:00 Graphene-a single layer...

218

X-Ray Photoelectron Spectroscopy (XPS) Applied to Soot & What...  

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

Photoelectron Spectroscopy (XPS) Applied to Soot & What It Can Do for You X-Ray Photoelectron Spectroscopy (XPS) Applied to Soot & What It Can Do for You Presentation given at DEER...

219

Core-level Spectroscopies with FEFF9 and OCEAN  

E-Print Network [OSTI]

Core-level Spectroscopies with FEFF9 and OCEAN J. J. Rehr1,4 K. Gilmore,2,4 J. Kas,1 J. Vinson,3 E European Theoretical Spectroscopy Facility Supported by DOE BES Soleil Theory Day Synchrotron SOLEIL, Grand Amphi 6/5/2014 #12;Core-level Spectroscopies with FEFF9 and OCEAN · GOAL: ab initio theory · Accuracy

Botti, Silvana

220

FRONTIER SYNCHROTRON INFRARED SPECTROSCOPY BEAMLINE UNDER EXTREME CONDITIONS (FIS)  

E-Print Network [OSTI]

FRONTIER SYNCHROTRON INFRARED SPECTROSCOPY BEAMLINE UNDER EXTREME CONDITIONS (FIS) Proposal Team: L INFORMATION · TECHNIQUE(S): Fourier transform infrared spectroscopy; Raman and visible spectroscopy; Diamond techniques combined with DACs; Laser heating techniques combined with DACs. · SOURCE: Large-gap (90 mm

Ohta, Shigemi

Note: This page contains sample records for the topic "angle-resolved photoemission spectroscopy" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

E-Print Network 3.0 - absorption spectroscopy measurements Sample...  

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

A partial sampling of these techniques includes: Absorption spectroscopy Atomic absorption... spectroscopy Auger electron ... Source: Yucca Mountain Project, US...

222

E-Print Network 3.0 - atomic spectroscopy study Sample Search...  

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

A partial sampling of these techniques includes: Absorption spectroscopy Atomic absorption... spectroscopy Atomic emission ... Source: Yucca Mountain Project,...

223

E-Print Network 3.0 - absorption edge spectroscopy Sample Search...  

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

Domain Spectroscopy From... Industrial applications: spectroscopy, imaging and security Terahertz: Research and Applications 12... of Photonic THz Radiation transmission &...

224

Meson Spectroscopy At Jlab At 12 Gev  

SciTech Connect (OSTI)

The 12 GeV upgrade to the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab will enable a new generation of experiments in hadronic nuclear physics, seeking to address fundamental questions in our understanding of QCD. The existence of exotic states, suggested by both quark models and lattice calculations, would allow gluonic degrees of freedom to be explored, and may help explain the role played by gluons in the QCD interaction. This article will review the meson spectroscopy program being planned at the lab following the 12 GeV upgrade, utilising real and quasi-real photon beams in two of the lab's four experimental halls, whose distinct capabilities will enable an extensive set of spectroscopy experiments to be performed at the same facility.

Fegan, Stuart [INFN-GENOVA

2014-12-01T23:59:59.000Z

225

Charge exchange recombination spectroscopy on fusion devices  

SciTech Connect (OSTI)

For fusion, obtaining reliable measurements of basic plasma parameters like ion and electron densities and temperatures is a primary goal. For theory, measurements are needed as a function of time and space to understand plasma transport and confinement with the ultimate goal of achieving economic nuclear fusion power. Electron profile measurements and plasma spectroscopy for the plasma ions are introduced. With the advent of Neutral Beam auxiliary plasma heating, Charge Exchange Recombination Spectroscopy provides accurate and time resolved measurements of the ions in large volume fusion devices. In acknowledgement of Nicol Peacock's role in the development of these techniques, still at the forefront of plasma fusion research, this paper describes the evolution of this diagnostic method.

Duval, B. P. [Centre de Recherches en Physique des Plasmas, EPFL, Lausanne (Switzerland)

2012-05-25T23:59:59.000Z

226

Standoff spectroscopy using a conditioned target  

DOE Patents [OSTI]

A system and method are disclosed for standoff spectroscopy of molecules (e.g. from a residue) on a surface from a distance. A source emits radiation that modifies or conditions the residue, such as through photodecomposition. A spectral generating source measures a spectrum of the residue before and after the residue is exposed to the radiation from that source. The two spectra are compared to produce a distinct identification of the residues on the surface or identify certain properties of the residue.

Van Neste, Charles W. (Kingston, TN); Morales-Rodriguez, Marissa E. (Knoxville, TN); Senesac, Lawrence R. (Knoxville, TN); Thundat, Thomas G. (Knoxville, TN)

2011-12-20T23:59:59.000Z

227

Spin noise spectroscopy of ZnO  

SciTech Connect (OSTI)

We investigate the thermal equilibrium dynamics of electron spins bound to donors in nanoporous ZnO by optical spin noise spectroscopy. The spin noise spectra reveal two noise contributions: A weak spin noise signal from undisturbed localized donor electrons with a dephasing time of 24 ns due to hyperfine interaction and a strong spin noise signal with a spin dephasing time of 5 ns which we attribute to localized donor electrons which interact with lattice defects.

Horn, H.; Berski, F.; Hübner, J.; Oestreich, M. [Institute for Solid State Physics, Leibniz Universität Hannover, Appelstr. 2, 30167 Hannover (Germany); Balocchi, A.; Marie, X. [INSA-CNRS-UPS, LPCNO, Université de Toulouse, 135 Av. de Rangueil, 31077 Toulouse (France); Mansur-Al-Suleiman, M.; Bakin, A.; Waag, A. [Institute of Semiconductor Technology, Technische Universität Braunschweig, Hans-Sommer-Straße 66, 38106 Braunschweig (Germany)

2013-12-04T23:59:59.000Z

228

New Spectroscopy at BaBar  

SciTech Connect (OSTI)

The Babar experiment at the SLAC B factory has accumulated a high luminosity that offers the possibility of systematic studies of quarkonium spectroscopy and of investigating rare new phenomena. Recent results in this field are presented. In recent times spectroscopy has become exciting again, after the discovery of new states that are not easily explained by conventional models. States such as the X(3872) and the Y(4260) could be new excited charmonium states, but require precise measurements for positive identification. The BaBar experiment [1] is installed at the asymmetric storage ring PEP-II. 90% of the data accumulated by BaBar are taken at the Y(4S) (10.58 GeV) and 10% just below (10.54 GeV). The BaBar detector includes a 5-layer, double-sided silicon vertex tracker and a 40-layer drift chamber in a 1.5 T solenoidal magnetic field, which detect charged particles and measures their momenta and ionization energy losses. Photons, electrons, and neutral hadrons are detected with a CsI(Tl)-crystal electromagnetic calorimeter. An internally reflecting ring-imaging Cherenkov is also used for particle id. Penetrating muon and neutral hadrons are identified by an array of resistive-plate chambers embedded in the steel of the flux return. The detector allows good track and vertex resolution, good particle id and good photon detection so it is especially suited for spectroscopy studies.

Mazzoni, M.A.; /INFN, Rome

2007-04-18T23:59:59.000Z

229

Electronic structure of the Si(111):GaSe van der Waals-like surface termination  

E-Print Network [OSTI]

Electronic structure of the Si(111):GaSe van der Waals-like surface termination Reiner Rudolph-like surface termination has been determined by angle-resolved photoelectron spectroscopy using photons. This explains both the absence of a surface core-level shift in Si 2p photoelectron spectra of the terminated

Olmstead, Marjorie

230

Robust surface electronic properties of topological insulators: Bi{sub 2}Te{sub 3} films grown by molecular beam epitaxy  

SciTech Connect (OSTI)

The surface electronic properties of the important topological insulator Bi{sub 2}Te{sub 3} are shown to be robust under an extended surface preparation procedure, which includes exposure to atmosphere and subsequent cleaning and recrystallization by an optimized in situ sputter-anneal procedure under ultrahigh vacuum conditions. Clear Dirac-cone features are displayed in high-resolution angle-resolved photoemission spectra from the resulting samples, indicating remarkable insensitivity of the topological surface state to cleaning-induced surface roughness.

Plucinski, L.; Herdt, A. [Peter Gruenberg Institut (PGI-6), Forschungszentrum Juelich, D-52425 Juelich (Germany); Mussler, G.; Krumrain, J.; Gruetzmacher, D. [Peter Gruenberg Institut (PGI-9), Forschungszentrum Juelich, D-52425 Juelich (Germany); Juelich Aachen Research Alliance-Fundamentals of Future Information Technologies (JARA-FIT), D-52425 Juelich (Germany); Suga, S. [Peter Gruenberg Institut (PGI-6), Forschungszentrum Juelich, D-52425 Juelich (Germany); Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531 (Japan); Schneider, C. M. [Peter Gruenberg Institut (PGI-6), Forschungszentrum Juelich, D-52425 Juelich (Germany); Juelich Aachen Research Alliance-Fundamentals of Future Information Technologies (JARA-FIT), D-52425 Juelich (Germany)

2011-05-30T23:59:59.000Z

231

Instability and Charge Density Wave of Metallic Quantum Chains on a Silicon Surface  

SciTech Connect (OSTI)

Self-assembled indium linear chains on the Si(111) surface are found to exhibit instability of the metallic phase and 1D charge density wave (CDW). The room-temperature metallic phase of these chains undergoes a temperature-induced, reversible transition into a semiconducting phase. The 1D CDW along the chains is observed directly in real space by scanning tunneling microscopy at low temperature. The Fermi contours of the metallic phase measured by angle-resolved photoemission exhibit a perfect nesting predicting precisely the CDW periodicity.

Takeda, S.; Rotenberg, E.; Matsuda, I.; Horikoshi, K.; Schà ƒ  ƒ à ‚  ¤fer, J.; Lee, C. M.; Kevan, S. D.; Ohta, T.; Nagao, T.

1999-06-14T23:59:59.000Z

232

Issues in Light Meson Spectroscopy: The Case for Meson Spectroscopy at Cebaf  

E-Print Network [OSTI]

I review some outstanding issues in meson spectroscopy. The most important qualitative issue is whether hadrons with explicit gluonic degrees of freedom exist. To answer this question requires a much better understanding of conventional $q\\bar{q}$ mesons. I therefore begin by examining the status of conventional meson spectroscopy and how the situation can be improved. The expected properties of gluonic excitations are discussed with particular emphasis on hybrids to give guidance to experimental searches. Multiquark systems are commented upon as they are likely to be important in the mass region under study and will have to be understood better. In the final section I discuss the opportunities that CEBAF can offer for the study of meson spectroscopy.

Stephen Godfrey

1994-06-10T23:59:59.000Z

233

ARPES study of the evolution of band structure and charge density wave properties in RTe3 ( R=Y , La, Ce, Sm, Gd, Tb, and Dy)  

SciTech Connect (OSTI)

We present a detailed angle-resolved photoemission spectroscopy (ARPES) investigation of the RTe3 family, which sets this system as an ideal"textbook" example for the formation of a nesting driven charge density wave (CDW). This family indeed exhibits the full range of phenomena that can be associated to CDWinstabilities, from the opening of large gaps on the best nested parts of Fermi surface (up to 0.4 eV), to the existence of residual metallic pockets. ARPES is the best suited technique to characterize these features, thanks to its unique ability to resolve the electronic structure in k space. An additional advantage of RTe3 is that theband structure can be very accurately described by a simple two dimensional tight-binding (TB) model, which allows one to understand and easily reproduce many characteristics of the CDW. In this paper, we first establish the main features of the electronic structure by comparing our ARPES measurements with the linear muffin-tinorbital band calculations. We use this to define the validity and limits of the TB model. We then present a complete description of the CDW properties and of their strong evolution as a function of R. Using simple models, we are able to reproduce perfectly the evolution of gaps in k space, the evolution of the CDW wave vector with R, and the shape of the residual metallic pockets. Finally, we give an estimation of the CDWinteraction parameters and find that the change in the electronic density of states n (EF), due to lattice expansion when different R ions are inserted, has the correct order of magnitude to explain the evolution of the CDW properties.

Hussain, Zahid; Brouet, Veronique; Yang, Wanli; Zhou, Xingjiang; Hussain, Zahid; Moore, R.G.; He, R.; Lu, D. H.; Shen, Z.X.; Laverock, J.; Dugdale, S.B.; Ru, N.; Fisher, R.

2008-01-16T23:59:59.000Z

234

Estimating radiological background using imaging spectroscopy  

SciTech Connect (OSTI)

Optical imaging spectroscopy is investigated as a method to estimate radiological background by spectral identification of soils, sediments, rocks, minerals and building materials derived from natural materials and assigning tabulated radiological emission values to these materials. Radiological airborne surveys are undertaken by local, state and federal agencies to identify the presence of radiological materials out of regulatory compliance. Detection performance in such surveys is determined by (among other factors) the uncertainty in the radiation background; increased knowledge of the expected radiation background will improve the ability to detect low-activity radiological materials. Radiological background due to naturally occurring radiological materials (NORM) can be estimated by reference to previous survey results, use of global 40K, 238U, and 232Th (KUT) values, reference to existing USGS radiation background maps, or by a moving average of the data as it is acquired. Each of these methods has its drawbacks: previous survey results may not include recent changes, the global average provides only a zero-order estimate, the USGS background radiation map resolutions are coarse and are accurate only to 1 km – 25 km sampling intervals depending on locale, and a moving average may essentially low pass filter the data to obscure small changes in radiation counts. Imaging spectroscopy from airborne or spaceborne platforms can offer higher resolution identification of materials and background, as well as provide imaging context information. AVIRIS hyperspectral image data is analyzed using commercial exploitation software to determine the usefulness of imaging spectroscopy to identify qualitative radiological background emissions when compared to airborne radiological survey data.

Bernacki, Bruce E.; Schweppe, John E.; Stave, Sean C.; Jordan, David V.; Kulisek, Jonathan A.; Stewart, Trevor N.; Seifert, Carolyn E.

2014-06-13T23:59:59.000Z

235

Construction and Commissioning of a Collinear Laser Spectroscopy Setup at TRIGA Mainz and Laser Spectroscopy of Magnesium Isotopes at ISOLDE (CERN)  

E-Print Network [OSTI]

Construction and Commissioning of a Collinear Laser Spectroscopy Setup at TRIGA Mainz and Laser Spectroscopy of Magnesium Isotopes at ISOLDE (CERN)

Kraemer, Joerg

236

Diagnostics of plasma photoemission at strong coupling  

E-Print Network [OSTI]

We compute the spectrum of photons emitted by the finite-temperature large-N SU(N) ${\\cal {N}}=4$ supersymmetric Yang-Mills plasma coupled to electromagnetism, at strong yet finite 't Hooft coupling. We work in the holographic dual description, extended by the inclusion of the full set of ${\\cal{O}}(\\alpha'^3)$ type IIB string theory operators that correct the minimal supergravity action. We find that, as the t' Hooft coupling decreases, the peak of the spectrum increases, and the momentum of maximal emission shifts towards the infra-red, as expected from weak-coupling computations. The total number of emitted photons also increases as the 't Hooft coupling weakens.

Babiker Hassanain; Martin Schvellinger

2011-10-03T23:59:59.000Z

237

(Resonance ionization spectroscopy and its applications)  

SciTech Connect (OSTI)

The field of Resonance Ionization Spectroscopy grew out of work done in the Photophysics Group at Oak Ridge National Laboratory. As one of the original developers of this field the traveler has continued to attend this meeting on a regular basis. The traveler was originally asked to present an invited talk and to present part of a short course offered to graduate students attending the conference. Subsequently, the traveler was also asked to chair a session and to be a judge of the students papers entered in a contest for a $1000 first prize.

Payne, M.G.

1990-10-05T23:59:59.000Z

238

Spectroscopy and Thermodynamics of MSW Black Hole  

E-Print Network [OSTI]

We study the thermodynamics and spectroscopy of a 2+1 dimensional black hole pro- posed by Mandal et. al1 . We put the background space time in Kruskal like co-ordinate and find period with respect to Euclidean time. Different thermodynamic quantities like entropy, specific heat, temperature etc are obtained. The adiabatic invariant for the black hole is found out and quantized using Bohr-Sommerfeld quantization rule. The study shows that the area spectrum of MSW black hole is equally spaced and the value of spacing is found to be h bar

Sebastian, Saneesh

2013-01-01T23:59:59.000Z

239

Spectroscopy and Thermodynamics of MSW Black Hole  

E-Print Network [OSTI]

We study the thermodynamics and spectroscopy of a 2+1 dimensional black hole pro- posed by Mandal et. al1 . We put the background space time in Kruskal like co-ordinate and find period with respect to Euclidean time. Different thermodynamic quantities like entropy, specific heat, temperature etc are obtained. The adiabatic invariant for the black hole is found out and quantized using Bohr-Sommerfeld quantization rule. The study shows that the area spectrum of MSW black hole is equally spaced and the value of spacing is found to be h bar

Saneesh Sebastian; V. C. Kuriakose

2013-09-02T23:59:59.000Z

240

Cavity-locked ring down spectroscopy  

DOE Patents [OSTI]

Distinct locking and sampling light beams are used in a cavity ring-down spectroscopy (CRDS) system to perform multiple ring-down measurements while the laser and ring-down cavity are continuously locked. The sampling and locking light beams have different frequencies, to ensure that the sampling and locking light are decoupled within the cavity. Preferably, the ring-down cavity is ring-shaped, the sampling light is s-polarized, and the locking light is p-polarized. Transmitted sampling light is used for ring-down measurements, while reflected locking light is used for locking in a Pound-Drever scheme.

Zare, Richard N. (Stanford, CA); Paldus, Barbara A. (Stanford, CA); Harb, Charles C. (Palo Alto, CA); Spence, Thomas (Union City, CA)

2000-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "angle-resolved photoemission spectroscopy" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Fractal properties applied to hadron spectroscopy  

E-Print Network [OSTI]

A contribution is presented to the study of hadron spectroscopy through the use of fractals and discrete scale invariance implying log-periodic corrections to continuous scaling. The masses of mesons and baryons, reported by the Particle Data Group (PDG), are properly fitted with help of the equation derived from the discrete-scale invariance (DSI) model. The same property is observed for the mass ratios between different particle species. This is also the case for total widths of several hadronic species. Each fitted parameter, as a function of the hadronic masses, displays the same distribution for all hadronic species. Several masses of still unobserved mesons and baryons are tentatively predicted.

Boris Tatischeff

2011-05-05T23:59:59.000Z

242

Ultrafast Spectroscopy of Warm Dense Matter  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched Ferromagnetism in Layeredof2014 EIA Energy40081AEnergyUltrafastUltrafast Spectroscopy

243

Theoretical standards in x-ray spectroscopies  

SciTech Connect (OSTI)

We propose to extend our state-of-the-art, ab initio XAFS (X-ray absorption fine structure) codes, FEFF. Our current work has been highly successful in achieving accurate, user-friendly XAFS standards, exceeding the performance of both tabulated standards and other codes by a considerable margin. We now propose to add the capability to treat more complex materials. This includes multiple-scattering, polarization dependence, an approximate treatment of XANES (x-ray absorption near edge structure), and other improvements. We also plan to adapt FEFF to other spectroscopies, e.g. photoelectron diffraction (PD) and diffraction anomalous fine structure (DAFS).

Not Available

1992-01-01T23:59:59.000Z

244

Study of clusters using negative ion photodetachment spectroscopy  

SciTech Connect (OSTI)

The weak van der Waals interaction between an open-shell halogen atom and a closed-shell atom or molecule has been investigated using zero electron kinetic energy (ZEKE) spectroscopy. This technique is also applied to study the low-lying electronic states in GaAs and GaAs{sup {minus}}. In addition, the spectroscopy and electron detachment dynamics of several small carbon cluster anions are studied using resonant multiphoton detachment spectroscopy.

Zhao, Yuexing

1995-12-01T23:59:59.000Z

245

IR Spectroscopy Spectroscopy: Branch of science in which light or other electromagnetic radiation  

E-Print Network [OSTI]

is resolved into its component wavelengths to produce spectra, which are graphs of intensity vs. wavelength or frequency of radiation. Current usage broadens this definition to include some methods that don't involve the energy difference of 2 quantum levels of the sample of matter. hE = IR Spectroscopy Tool for examining

Sherrill, David

246

Theory and Applications of NMR Spectroscopy Arthur S. Edison  

E-Print Network [OSTI]

. Prerequisites: Graduate student or advanced undergraduate status, physical chemistry, organic chemistry Spectroscopy Week 1: Introduction to the basics: Bloch equations References: Most NMR books. These notes were

Collins, Gary S.

247

Graphene and its derivatives : fabrication and Raman spectroscopy study.  

E-Print Network [OSTI]

??This thesis presents results on fabrication and Raman spectroscopy studies of graphene and its derivates. The works can be divided into two parts as follows.… (more)

Cong, Chunxiao.

2012-01-01T23:59:59.000Z

248

E-Print Network 3.0 - absorption spectroscopy characterization...  

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

and Restoration Technologies 87 Terahertz Time-Domain Spectroscopy Study of Silica Aerogels and Adsorbed Molecular Jiangquan Zhang and D. Grischkowsky* Summary: absorption...

249

Wave functions and their use in spectroscopy and phenomenology  

E-Print Network [OSTI]

We describe the calculation of Coulomb gauge wave functions for light quark systems, and their use as interpolating fields for excited state spectroscopy.

T. DeGrand; M. Hecht

1992-10-08T23:59:59.000Z

250

annihilation spectroscopy applied: Topics by E-print Network  

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

the mid-IR spectral Society for Applied Spectroscopy accelerated paper Negligible Sample Heating from Synchrotron Infrared, they could cause damage to biological molecules due to...

251

applying gamma spectroscopy: Topics by E-print Network  

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

the mid-IR spectral Society for Applied Spectroscopy accelerated paper Negligible Sample Heating from Synchrotron Infrared, they could cause damage to biological molecules due to...

252

First Principles Calculations and NMR Spectroscopy of Electrode...  

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

Calculations and NMR Spectroscopy of Electrode Materials 2011 DOE Hydrogen and Fuel Cells Program, and Vehicle Technologies Program Annual Merit Review and Peer Evaluation...

253

Natural Abundance 43Ca NMR Spectroscopy of Tobermorite and Jennite...  

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

which has limited our ability to understand the structure of, for example, Ca–silicate hydrate (C–S–H). 43Ca nuclear magnetic resonance (NMR) spectroscopy has...

254

Single Molecule Spectroscopy of Electron Transfer  

SciTech Connect (OSTI)

The objectives of this research are threefold: (1) to develop methods for the study electron transfer processes at the single molecule level, (2) to develop a series of modifiable and structurally well defined molecular and nanoparticle systems suitable for detailed single molecule/particle and bulk spectroscopic investigation, (3) to relate experiment to theory in order to elucidate the dependence of electron transfer processes on molecular and electronic structure, coupling and reorganization energies. We have begun the systematic development of single molecule spectroscopy (SMS) of electron transfer and summaries of recent studies are shown. There is a tremendous need for experiments designed to probe the discrete electronic and molecular dynamic fluctuations of single molecules near electrodes and at nanoparticle surfaces. Single molecule spectroscopy (SMS) has emerged as a powerful method to measure properties of individual molecules which would normally be obscured in ensemble-averaged measurement. Fluctuations in the fluorescence time trajectories contain detailed molecular level statistical and dynamical information of the system. The full distribution of a molecular property is revealed in the stochastic fluctuations, giving information about the range of possible behaviors that lead to the ensemble average. In the case of electron transfer, this level of understanding is particularly important to the field of molecular and nanoscale electronics: from a device-design standpoint, understanding and controlling this picture of the overall range of possible behaviors will likely prove to be as important as designing ia the ideal behavior of any given molecule.

Michael Holman; Ling Zang; Ruchuan Liu; David M. Adams

2009-10-20T23:59:59.000Z

255

High-harmonic spectroscopy of molecular isomers  

SciTech Connect (OSTI)

We demonstrate that high-order-harmonic generation (HHG) spectroscopy can be used to probe stereoisomers of randomly oriented 1,2-dichloroethylene (C{sub 2}H{sub 2}Cl{sub 2}) and 2-butene (C{sub 4}H{sub 8}). The high-harmonic spectra of these isomers are distinguishable over a range of laser intensities and wavelengths. Time-dependent numerical calculations of angle-dependent ionization yields for 1,2-dichloroethylene suggest that the harmonic spectra of molecular isomers reflect differences in their strong-field ionization. The subcycle ionization yields for the cis isomer are an order of magnitude higher than those for the trans isomer. The sensitivity in discrimination of the harmonic spectra of cis- and trans- isomers is greater than 8 and 5 for 1,2-dichloroethylene and 2-butene, respectively. We show that HHG spectroscopy cannot differentiate the harmonic spectra of the two enantiomers of the chiral molecule propylene oxide (C{sub 3}H{sub 6}O).

Wong, M. C. H.; Brichta, J.-P.; Bhardwaj, V. R. [Department of Physics, University of Ottawa, 150 Louis-Pasteur, Ottawa, Ontario, K1N 6N5 (Canada); Spanner, M.; Patchkovskii, S. [National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario, K1A 0R6 (Canada)

2011-11-15T23:59:59.000Z

256

High fidelity nanohole enhanced Raman spectroscopy.  

SciTech Connect (OSTI)

Surface enhanced Raman spectroscopy (SERS) is a sensitive technique that can even detect single molecules. However, in many SERS applications, the strongly inhomogeneous distribution of intense local fields makes it very difficult for a quantitive assessment of the fidelity, or reproducibility of the signal, which limits the application of SERS. Herein, we report the development of exceptionally high-fidelity hole-enhanced Raman spectroscopy (HERS) from ordered, 2D hexagonal nanohole arrays. We take the fidelity f to be a measure of the percent deviation of the Raman peaks from measurement to measurement. Overall, area averaged fidelities for 12 gold array samples ranged from f {approx} 2-15% for HERS using aqueous R6G molecules. Furthermore, intensity modulations of the enhanced Raman spectra were measured for the first time as a function of polarization angle. The best of these measurements, which focus on static laser spots on the sample, could be consistent with even higher fidelities than the area-averaged results. Nanohole arrays in silver provided supporting polarization measurements and a more complete enhanced Raman fingerprint for phenylalanine molecules. We also carried out finite-difference time-domain calculations to assist in the interpretation of the experiments, identifying the polarization dependence as possibly arising from hole-hole interactions. Our results represent a step toward making quantitative and reproducible enhanced Raman measurements possible and also open new avenues for a large-scale source of highly uniform hot spots.

Bahns, J. T.; Guo, Q.; Gray, S. K.; Jaeger, H. M.; Chen, L.; Montgomery, J. M.; Univ. of Chicago

2009-01-01T23:59:59.000Z

257

Rotational Spectroscopy of PAHs: Acenaphthene, Acenaphthylene and Fluorene  

E-Print Network [OSTI]

Pure rotational spectra of three polycyclic aromatic hydrocarbons - acenaphthene, acenaphthylene and fluorene - have been obtained by Fourier transform microwave spectroscopy of a molecular beam and subsequently by millimeter wave absorption spectroscopy for acenaphthene and fluorene. The data presented here will be useful for deep radio astronomical searches for PAHs employing large radio telecopes.

Thorwirth, S; Gottlieb, C A; McCarthy, M C; Thaddeus, P

2005-01-01T23:59:59.000Z

258

Rotational Spectroscopy of PAHs: Acenaphthene, Acenaphthylene and Fluorene  

E-Print Network [OSTI]

Pure rotational spectra of three polycyclic aromatic hydrocarbons - acenaphthene, acenaphthylene and fluorene - have been obtained by Fourier transform microwave spectroscopy of a molecular beam and subsequently by millimeter wave absorption spectroscopy for acenaphthene and fluorene. The data presented here will be useful for deep radio astronomical searches for PAHs employing large radio telecopes.

S. Thorwirth; P. Theule; C. A. Gottlieb; M. C. McCarthy; P. Thaddeus

2005-09-23T23:59:59.000Z

259

Scanning tunneling spectroscopy of suspended single-wall carbon nanotubes  

E-Print Network [OSTI]

Scanning tunneling spectroscopy of suspended single-wall carbon nanotubes B. J. LeRoy,a) S. G-wall carbon nanotubes that are freely suspended over a trench. The nanotubes were grown by chemical vapor on the freestanding portions of the nanotubes. Spatially resolved spectroscopy on the suspended portion of both

Dekker, Cees

260

Infrared modulation spectroscopy of interfaces in amorphous silicon solar cells  

E-Print Network [OSTI]

Infrared modulation spectroscopy of interfaces in amorphous silicon solar cells Kai Zhu a,1 , E Solar, Toano, VA 23168, USA Abstract We report infrared depletion modulation spectra for near an infrared modulation spectroscopy technique that probes the optical spectra of dopants and defects

Schiff, Eric A.

Note: This page contains sample records for the topic "angle-resolved photoemission spectroscopy" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

production under ionizing radiation in aluminoborosilicate glasses by EPR spectroscopy.  

E-Print Network [OSTI]

1 Ti3+ production under ionizing radiation in aluminoborosilicate glasses by EPR spectroscopy. P irradiation of Ti4+ ions in aluminoborosilicate glasses have been studied by EPR spectroscopy at 20 K of the Ti3+ ion EPR spectra has shown three different Ti3+ environment attributed to one [VI] Ti3+ and two

Paris-Sud XI, Université de

262

Near-infrared spectroscopy of HD the barrier to linearity  

E-Print Network [OSTI]

Near-infrared spectroscopy of HD 3 above the barrier to linearity BY JENNIFER L. GOTTFRIED, transitions of HC 3 above the barrier to linearity have been observed. A highly sensitive near-infrared-adiabatic and radiative corrections is revealed. Keywords: HD 3 ; near-infrared spectroscopy; barrier to linearity 1

Oka, Takeshi

263

Optical Spectroscopy of Hydrogenic Atoms MIT Department of Physics  

E-Print Network [OSTI]

Optical Spectroscopy of Hydrogenic Atoms MIT Department of Physics (Dated: September 1, 2013) This experiment is an exercise in optical spectroscopy in a study of the spectra of "hydrogenic" atoms, i.e. atoms with one "optical" electron outside a closed shell of other electrons. Measurements include finding

Seager, Sara

264

Deflecting light into resonant cavities for spectroscopy  

DOE Patents [OSTI]

Light is coupled into a cavity ring down spectroscopy (CRDS) resonant cavity using an acousto-optic modulator. The AOM allows in-coupling efficiencies in excess of 40%, which is two to three orders of magnitude higher than in conventional systems using a cavity mirror for in-coupling. The AOM shutoff time is shorter than the roundtrip time of the cavity. The higher light intensities lead to a reduction in shot noise, and allow the use of relatively insensitive but fast-responding detectors such as photovoltaic detectors. Other deflection devices such as electro-optic modulators or elements used in conventional Q-switching may be used instead of the AOM. The method is particularly useful in the mid-infrared, far-infrared, and ultraviolet wavelength ranges, for which moderately reflecting input mirrors are not widely available.

Zare, Richard N. (Stanford, CA); Martin, Juergen (Harxheim, DE); Paldus, Barbara A. (Stanford, CA)

1998-01-01T23:59:59.000Z

265

Pressurised xenon as scintillator for gamma spectroscopy  

E-Print Network [OSTI]

Detectors based on liquid or gas xenon have been used and are in use for a number of applications, in particular for the detection of gamma rays. Xenon is a well-suited medium for gamma spectroscopy thanks to its high atomic number and, consequently, large cross-section for photo-electric absorption. This paper presents experimental studies of high pressure xenon as a scintillator, with the aim of developing a gamma ray detector for the detection of Special Nuclear Materials (SNM). The first goal was to study the dependence of the light yield and of the energy resolution on the thermodynamic conditions. We present preliminary results from an optimised version of the detector.

Resnati, F

2013-01-01T23:59:59.000Z

266

Deflecting light into resonant cavities for spectroscopy  

DOE Patents [OSTI]

Light is coupled into a cavity ring down spectroscopy (CRDS) resonant cavity using an acousto-optic modulator. The AOM allows in-coupling efficiencies in excess of 40%, which is two to three orders of magnitude higher than in conventional systems using a cavity mirror for in-coupling. The AOM shutoff time is shorter than the roundtrip time of the cavity. The higher light intensities lead to a reduction in shot noise, and allow the use of relatively insensitive but fast-responding detectors such as photovoltaic detectors. Other deflection devices such as electro-optic modulators or elements used in conventional Q-switching may be used instead of the AOM. The method is particularly useful in the mid-infrared, far-infrared, and ultraviolet wavelength ranges, for which moderately reflecting input mirrors are not widely available. 5 figs.

Zare, R.N.; Martin, J.; Paldus, B.A.

1998-09-29T23:59:59.000Z

267

Anion photoelectron spectroscopy of radicals and clusters  

SciTech Connect (OSTI)

Anion photoelectron spectroscopy is used to study free radicals and clusters. The low-lying {sup 2}{Sigma} and {sup 2}{Pi} states of C{sub 2n}H (n = 1--4) have been studied. The anion photoelectron spectra yielded electron affinities, term values, and vibrational frequencies for these combustion and astrophysically relevant species. Photoelectron angular distributions allowed the author to correctly assign the electronic symmetry of the ground and first excited states and to assess the degree of vibronic coupling in C{sub 2}H and C{sub 4}H. Other radicals studied include NCN and I{sub 3}. The author was able to observe the low-lying singlet and triplet states of NCN for the first time. Measurement of the electron affinity of I{sub 3} revealed that it has a bound ground state and attachment of an argon atom to this moiety enabled him to resolve the symmetric stretching progression.

Travis, Taylor R.

1999-12-16T23:59:59.000Z

268

Remote adjustable focus Raman spectroscopy probe  

DOE Patents [OSTI]

A remote adjustable focus Raman spectroscopy probe allows for analyzing Raman scattered light from a point of interest external probe. An environmental barrier including at least one window separates the probe from the point of interest. An optical tube is disposed adjacent to the environmental barrier and includes a long working length compound lens objective next to the window. A beam splitter and a mirror are at the other end. A mechanical means is used to translated the prove body in the X, Y, and Z directions resulting in a variable focus optical apparatus. Laser light is reflected by the beam splitter and directed toward the compound lens objective, then through the window and focused on the point of interest. Raman scattered light is then collected by the compound lens objective and directed through the beam splitter to a mirror. A device for analyzing the light, such as a monochrometer, is coupled to the mirror.

Schmucker, John E. (Hurt, VA); Blasi, Raymond J. (Harrison City, PA); Archer, William B. (Bethel Park, PA)

1999-01-01T23:59:59.000Z

269

New Results on Baryon Spectroscopy from MAMI  

SciTech Connect (OSTI)

An overview of the MAMI-C electron accelerator facility (E{sub 0} = 1.6 GeV) and the experimental setups of the A1 and A2 collaborations for electro- and photoproduction reactions is given. Several experimental results and their interpretations for baryon spectroscopy are discussed. The topics presented here are the beam-helicity asymmetry I{center_dot} for {pi}{pi} photoproduction in the second resonance region, the photoproduction of {pi}{sup 0{eta}} up to beam energies of {omega} = 1.4 GeV as a way to study the {Delta}(1700)D{sub 33} baryon, and polarisation observables in h electro- and photoproduction in order to investigate an unexpected s-d-wave phase shift and its possible implications for the nature of the S{sub 11}(1535) resonance.

Schumann, Sven [Institut fuer Kernphysik, Johannes Gutenberg-Universitaet, Mainz (Germany)

2010-08-05T23:59:59.000Z

270

Development of the charge exchange recombination spectroscopy and the beam emission spectroscopy on the EAST tokamak  

SciTech Connect (OSTI)

Charge eXchange Recombination Spectroscopy (CXRS) and Beam Emission Spectroscopy (BES) diagnostics based on a heating neutral beam have recently been installed on EAST to provide local measurements of ion temperature, velocity, and density. The system design features common light collection optics for CXRS and BES, background channels for the toroidal views, multi-chord viewing sightlines, and high throughput lens-based spectrometers with good signal to noise ratio for high time resolution measurements. Additionally, two spectrometers each has a tunable grating to observe any wavelength of interest are used for the CXRS and one utilizes a fixed-wavelength grating to achieve higher diffraction efficiency for the BES system. A real-time wavelength correction is implemented to achieve a high-accuracy wavelength calibration. Alignment and calibration are performed. Initial performance test results are presented.

Li, Y. Y.; Fu, J.; Lyu, B., E-mail: blu@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Du, X. W.; Li, C. Y.; Yu, Y.; Wang, Q. P. [School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui 230026 (China); Zhang, Y.; Yin, X. H.; Ye, M. Y.; Wan, B. N. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui 230026 (China); Hellermann, M. von [FOM-Institute for Plasma Physics “Rijnhuizen,” Association EURATOM, Trilateral Euregio Cluster, 3430BE Nieuwegein (Netherlands); Shi, Y. J. [School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui 230026 (China); WCI for Fusion Theory, National Fusion Research Institute, 52 Eoeun-Dong, Yusung-Gu, Daejeon 305-333 (Korea, Republic of)

2014-11-15T23:59:59.000Z

271

images/logoetsf Introduction Electron Energy Loss Spectroscopy Applications: Nanotubes and Graphene Perspectives  

E-Print Network [OSTI]

images/logoetsf Introduction Electron Energy Loss Spectroscopy Applications: Nanotubes and Graphene excitations Francesco Sottile #12;Introduction Electron Energy Loss Spectroscopy Applications: Nanotubes excitations Francesco Sottile #12;Introduction Electron Energy Loss Spectroscopy Applications: Nanotubes

Botti, Silvana

272

Harmonic wavelet analysis of modulated tunable diode laser absorption spectroscopy signals  

E-Print Network [OSTI]

of the direct absorption characteristics of atomic or molecular absorption lines. This is accomplishedHarmonic wavelet analysis of modulated tunable diode laser absorption spectroscopy signals Hong analyses of tunable diode laser absorption spectroscopy signals were performed. The absorption spectroscopy

Cheng, Harry H.

273

Faraday rotation spectroscopy of nitrogen dioxide based on a widely tunable external cavity quantum cascade laser  

E-Print Network [OSTI]

Faraday rotation spectroscopy of nitrogen dioxide based on a widely tunable external cavity quantum: Faraday Rotation Spectroscopy, external-cavity quantum cascade laser, nitrogen dioxide, trace

274

Spectroscopy of Photovoltaic Materials: Charge-Transfer Complexes and Titanium Dioxide  

E-Print Network [OSTI]

RIVERSIDE Spectroscopy of Photovoltaic Materials: Charge-DISSERTATION Spectroscopy of Photovoltaic Materials: Charge-function of photovoltaic (PV) and photocatalytic (PC)

Dillon, Robert

2013-01-01T23:59:59.000Z

275

E-Print Network 3.0 - applications spectroscopie du Sample Search...  

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

DivisionOptical Spectroscopy DivisionOptical Spectroscopy ... Source: McCombe, Bruce D. - Department of Physics, State University of New York at Buffalo Collection:...

276

Soft X-Ray Microscopy and Spectroscopy at the Molecular Environmental...  

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

Soft X-Ray Microscopy and Spectroscopy at the Molecular Environmental Science Beamline at the Advanced Light Source. Soft X-Ray Microscopy and Spectroscopy at the Molecular...

277

E-Print Network 3.0 - absorption spectroscopy techniques Sample...  

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

A partial sampling of these techniques includes: Absorption spectroscopy Atomic absorption... 109 3.4 Spectroscopic Sensors Spectroscopy is the scientific study of...

278

Methods for measurement of heterogeneous materials with laser-induced breakdown spectroscopy (LIBS)  

E-Print Network [OSTI]

2000. 15) Welz B, Atomic Absorption Spectrometry, ThirdFor elemental analyses atomic absorption spectroscopy iscommonly used (15). Atomic absorption spectroscopy works by

Effenberger, Andrew Jay

2009-01-01T23:59:59.000Z

279

E-Print Network 3.0 - atomic spectroscopy programacion Sample...  

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

Name Summary: of an unknown metal ion in a biomolecule Atomic absorption spectroscopy or ICP spectroscopy (b) the presence... coordinated to...

280

E-Print Network 3.0 - atomic spectroscopy sympsoium Sample Search...  

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

Name Summary: of an unknown metal ion in a biomolecule Atomic absorption spectroscopy or ICP spectroscopy (b) the presence... coordinated to...

Note: This page contains sample records for the topic "angle-resolved photoemission spectroscopy" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

INFRARED ABSORPTION SPECTROSCOPY OF CARBON MONOXIDE ON NICKEL FILMS: A LOW TEMPERATURE THERMAL DETECTION TECHNIQUE  

E-Print Network [OSTI]

A. B. Optical System Absorption Signal C. Small SignalNoise . Sensitivity of Absorption Spectroscopy EXPERIMENTSINFRARED ABSORPTION SPECTROSCOPY OF CARBON MONOXIDE ON

Bailey, Robert Brian

2011-01-01T23:59:59.000Z

282

E-Print Network 3.0 - absorption spectroscopy diagnostics Sample...  

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

Domain Spectroscopy From... Industrial applications: spectroscopy, imaging and security Terahertz: Research and Applications 12... in a volume Measuring of moisture in a volume...

283

E-Print Network 3.0 - astronomical infrared spectroscopy Sample...  

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

spectroscopy. Projects: Principal Investigator, NSF ATI grant for development... of near infrared laser frequency comb for precision NIR spectroscopy and RV planet finding...

284

E-Print Network 3.0 - anharmonic vibrational spectroscopy Sample...  

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

spectroscopy Page: << < 1 2 3 4 5 > >> 1 Chem 791 Molecular Spectroscopy Spring 2008 Chemistry 791 Summary: branches. - Anharmonicity: electrical; mechanical. Violation of v 1...

285

Indium diffusion through high-k dielectrics in high-k/InP stacks  

SciTech Connect (OSTI)

Evidence of indium diffusion through high-k dielectric (Al{sub 2}O{sub 3} and HfO{sub 2}) films grown on InP (100) by atomic layer deposition is observed by angle resolved X-ray photoelectron spectroscopy and low energy ion scattering spectroscopy. The analysis establishes that In-out diffusion occurs and results in the formation of a PO{sub x} rich interface.

Dong, H.; Cabrera, W.; Santosh KC,; Brennan, B.; Qin, X.; McDonnell, S.; Hinkle, C. L.; Cho, K.; Chabal, Y. J. [Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, Texas 75080 (United States)] [Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, Texas 75080 (United States); Galatage, R. V. [Department of Electrical Engineering, University of Texas at Dallas, Richardson, Texas 75080 (United States)] [Department of Electrical Engineering, University of Texas at Dallas, Richardson, Texas 75080 (United States); Zhernokletov, D. [Department of Physics, University of Texas at Dallas, Richardson, Texas 75080 (United States)] [Department of Physics, University of Texas at Dallas, Richardson, Texas 75080 (United States); Wallace, R. M. [Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, Texas 75080 (United States) [Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, Texas 75080 (United States); Department of Physics, University of Texas at Dallas, Richardson, Texas 75080 (United States)

2013-08-05T23:59:59.000Z

286

Validating the Melusine Gamma Spectroscopy Tool  

SciTech Connect (OSTI)

This technical report describes testing to evaluate the gamma spectroscopy tool, Melusine, under development by Pacific Northwest National Laboratory. The goal was to verify that the software can successfully be used to provide accurate results and statistical uncertainties for the detection of isotopes of interest and their activities. Of special interest were spectra similar to those produced by radionuclide stations that contribute to the Comprehensive Nuclear Test Ban Treaty Organization’s International Monitoring System. Two data sets were used to test Melusine’s capabilities. The first was the result of a multi-lab calibration effort based on neutron activations produced at the University of California at Davis. The second was taken from the Proficiency Test Exercises conducted by the CTBTO directly in 2005. In 37 of 42 cases, Melusine produced results in agreement with the best answer presently available, in most cases with calculated uncertainties comparable to or better than competing analyses. In fact, Melusine technically provided one more result than CTBTO’s PTE analyses that agreed with the “book answer” (Monte Carlo simulation). Despite these promising results, the Melusine software is still under development. Effort is especially needed to simplify its analysis process, improve stability, and provide user documentation. Some significant analysis tasks require further vetting, such as those to address summing effects. However, our test results indicate that Melusine’s calculations as presently implemented are sound and can be used to reliably analyze spectra from the CTBTO’s radionuclide stations.

Erikson, Luke E.; Keillor, Martin E.; Stavenger, Timothy J.

2013-11-26T23:59:59.000Z

287

NAIS: Nuclear activation-based imaging spectroscopy  

SciTech Connect (OSTI)

In recent years, the development of high power laser systems led to focussed intensities of more than 10{sup 22} W/cm{sup 2} at high pulse energies. Furthermore, both, the advanced high power lasers and the development of sophisticated laser particle acceleration mechanisms facilitate the generation of high energetic particle beams at high fluxes. The challenge of imaging detector systems is to acquire the properties of the high flux beam spatially and spectrally resolved. The limitations of most detector systems are saturation effects. These conventional detectors are based on scintillators, semiconductors, or radiation sensitive films. We present a nuclear activation-based imaging spectroscopy method, which is called NAIS, for the characterization of laser accelerated proton beams. The offline detector system is a combination of stacked metal foils and imaging plates (IP). After the irradiation of the stacked foils they become activated by nuclear reactions, emitting gamma decay radiation. In the next step, an autoradiography of the activated foils using IPs and an analysis routine lead to a spectrally and spatially resolved beam profile. In addition, we present an absolute calibration method for IPs.

Günther, M. M.; Britz, A.; Harres, K.; Hoffmeister, G.; Nürnberg, F.; Otten, A.; Pelka, A.; Roth, M. [Institut für Kernphysik, Schlossgartenstr. 9, Technische Universität Darmstadt, D-64289 Darmstadt (Germany)] [Institut für Kernphysik, Schlossgartenstr. 9, Technische Universität Darmstadt, D-64289 Darmstadt (Germany); Clarke, R. J. [Central Laser Facility, Rutherford Appelton Laboratory, Chilton, Didcot, Oxon OX11 0QX (United Kingdom)] [Central Laser Facility, Rutherford Appelton Laboratory, Chilton, Didcot, Oxon OX11 0QX (United Kingdom); Vogt, K. [GSI – Helmholtzzentrum für Schwerionenforschung GmbH, D-64291 Darmstadt (Germany)] [GSI – Helmholtzzentrum für Schwerionenforschung GmbH, D-64291 Darmstadt (Germany)

2013-07-15T23:59:59.000Z

288

Laser-induced plasma spectroscopy: principles, methods and applications  

SciTech Connect (OSTI)

Principles of the Laser Induced Plasma Spectroscopy and its advances are reported. Methods for obtaining quantitative analyses are described, together with discussion of some applications and the specific problems.

Lazic, Violeta; Colao, Francesco; Fantoni, Roberta; Spizzichino, Valeria [ENEA, FIS-LAS, V. E. Fermi 45, Frascati (RM) (Italy); Jovicevic, Sonja [Institute of Physics, 11080 Belgrade, Pregrevica 118 (Serbia and Montenegro)

2006-12-01T23:59:59.000Z

289

Investigation of Zeolite Nucleation and Growth Using NMR Spectroscopy  

E-Print Network [OSTI]

and control of the zeolite properties. The primary objective of this dissertation is to determine the strength of organicinorganic interactions (i.e., the adsorption Gibbs energy) in transparent synthesis mixtures using PFG NMR spectroscopy, in order...

Rivas Cardona, Alejandra

2012-02-14T23:59:59.000Z

290

Testing Spin-Statistics Connection by Highly Sensitive Spectroscopy  

E-Print Network [OSTI]

Testing Spin-Statistics Connection by Highly Sensitive Spectroscopy of CO2 Y.-H. Lien ,Y.-L. Hsu ,Y #12;Experimental Scheme Searching for the very weak or even nonexistent J=(2n+1) transitions 2 µm 0000

Shy,Jow-Tsong

291

Hyperfine Studies of Lithium Vapor using Saturated Absorption Spectroscopy  

E-Print Network [OSTI]

the frequency of a laser with respect to an atomic spectral feature.[20] As such, saturated absorptionHyperfine Studies of Lithium Vapor using Saturated Absorption Spectroscopy? . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 3.3 Broadening Mechanisms . . . . . . . . . . . . . . . . . . . . . 15 3.4 Saturated Absorption

Cronin, Alex D.

292

Detection of Physiologically Relevant Alcohol Concentrations Using Raman Spectroscopy  

E-Print Network [OSTI]

This is the first step in a series of studies to test the feasibility of using Raman Spectroscopy (RS) to non-invasively detect physiologically relevant blood alcohol concentrations. Blood tests, urine tests, and the breathalyzer are currently...

McKay, Joshua L.

2006-08-16T23:59:59.000Z

293

Surface enhanced Raman spectroscopy on a flat graphene surface  

E-Print Network [OSTI]

Surface enhanced Raman spectroscopy (SERS) is an attractive analytical technique, which enables single-molecule sensitive detection and provides its special chemical fingerprints. During the past decades, researchers have ...

Xu, Weigao

294

Early diagnosis of cancer using light scattering spectroscopy  

E-Print Network [OSTI]

This thesis presents a novel optical technique, light scattering spectroscopy (LSS), developed for quantitative characterization of tissue morphology as well as in vivo detection and diagnosis of the diseases associated ...

Backman, Vadim, 1973-

2001-01-01T23:59:59.000Z

295

Thermal unfolding dynamics of proteins probed by nonlinear infrared spectroscopy  

E-Print Network [OSTI]

This thesis presents spectroscopic approaches to study the thermal unfolding dynamics of proteins. The spectroscopic tool is nonlinear infrared (IR) spectroscopy of the protein amide I band. Among various nonlinear IR ...

Chung, Hoi Sung

2007-01-01T23:59:59.000Z

296

Quantitative biological Raman spectroscopy for non-invasive blood analysis  

E-Print Network [OSTI]

The long term goal of this project is the measurement of clinically-relevant analytes in the blood tissue matrix of human subjects using near-infrared Raman spectroscopy, with the shorter term research directed towards ...

Shih, Wei-Chuan

2007-01-01T23:59:59.000Z

297

Dirac Charge Dynamcs in Graphene by Infrared Spectroscopy  

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

Dirac Charge Dynamcs in Graphene by Infrared Spectroscopy Print Graphene-a single layer of carbon atoms arranged in a honeycomb lattice-has very high conductivity that can be tuned...

298

Photoinduced phase transitions studied by femtosecond single-shot spectroscopy  

E-Print Network [OSTI]

Single-shot femtosecond spectroscopy has been developed and employed for the study of phase transitions of solid-state materials. Using two crossed echelons, a two dimensional spatial delay gradient was generated across a ...

Shin, Taeho

2010-01-01T23:59:59.000Z

299

absorption spectroscopy study: Topics by E-print Network  

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

14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 On Automatic Absorption Detection for Imaging Spectroscopy: A Comparative Study Computer Technologies and...

300

Photoelectron Spectroscopy of Doubly and Singly Charged Group...  

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

Doubly and Singly Charged Group VIB Dimetalate Anions: M2O72-, MM'072-, and M207- (M, M'Cr, Mo, W Photoelectron Spectroscopy of Doubly and Singly Charged Group VIB Dimetalate...

Note: This page contains sample records for the topic "angle-resolved photoemission spectroscopy" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Photoelectron Spectroscopy of Free Multiply Charged Keggin Anions...  

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

Free Multiply Charged Keggin Anions ?-PM12O403- (M Mo, W) in the Gas Phase. Photoelectron Spectroscopy of Free Multiply Charged Keggin Anions ?-PM12O403- (M Mo,...

302

CODED SPECTROSCOPY FOR ETHANOL DETECTION IN DIFFUSE, FLUORESCENT MEDIA  

E-Print Network [OSTI]

ABSTRACT CODED SPECTROSCOPY FOR ETHANOL DETECTION IN DIFFUSE, FLUORESCENT MEDIA by Scott Thomas Mc FOR ETHANOL DETECTION IN DIFFUSE, FLUORESCENT MEDIA by Scott Thomas McCain Department of Electrical

303

Femtosecond time-resolved spectroscopy of coherent oscillations in nanomaterials  

E-Print Network [OSTI]

FEMTOSECOND TIME-RESOLVED SPECTROSCOPY OF COHERENT OSCILLATIONS IN NANOMATERIALS A Dissertation by SERGUEI JEREBTSOV Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree... of DOCTOR OF PHILOSOPHY May 2007 Major Subject: Physics FEMTOSECOND TIME-RESOLVED SPECTROSCOPY OF COHERENT OSCILLATIONS IN NANOMATERIALS A Dissertation by SERGUEI JEREBTSOV Submitted to the Office of Graduate Studies of Texas A&M University in partial...

Jerebtsov, Serguei Nikolaevich

2009-05-15T23:59:59.000Z

304

Chemical Shifts in X-ray and Photo-Electron Spectroscopy: A Historical review  

E-Print Network [OSTI]

Chemical Shifts in X-ray and Photo-Electron Spectroscopy: A Historical review Ingvar Lindgren 1 Introduction 2 2 Chemical shift in X-ray spectroscopy 2 2.1 Discovery of the chemical shift in X-ray spectroscopy . . . . . . . . . . . . . 3 2.2 Interpretation of the chemical shift in X-ray spectroscopy

Lindgren, Ingvar

305

THE DEEP SWIRE FIELD. III. WIYN SPECTROSCOPY  

SciTech Connect (OSTI)

We present the results of spectroscopy using HYDRA on the WIYN 3.5 m telescope of objects in the deep SWIRE radio field. The goal of the project was to determine spectroscopic redshifts for as many of the brighter objects in the field as possible, especially those detected in the radio and at 24 {mu}m. These redshifts are primarily being used in studies of galaxy evolution and the connection of that evolution to active galactic nuclei and star formation. Redshifts measured for 365 individual objects are reported. The redshifts range from 0.03 to 2.5, mostly with z < 0.9. The sources were selected to be within the WIYN HYDRA field of approximately 30' in radius from the center of the SWIRE deep field, 10{sup h}46{sup m}00{sup s}, 59{sup 0}01'00'' (J2000). Optical sources for spectroscopic observation were selected from an r-band image of the field. A priority list of spectroscopic targets was established in the following order: 20 cm detections, 24 m detections, galaxies with r < 20 and the balance made up of fainter galaxies in the field. We provide a table listing the galaxy positions, measured redshift and error, and note any emission lines that were visible in the spectrum. In practice, almost all the galaxies with r < 19 were observed including all of the radio sources and most of the 24 {mu}m sources with r < 20 and a sample of radio sources which had fainter optical counterparts on the r-band image.

Owen, Frazer N. [National Radio Astronomy Observatory , P.O. Box O, Socorro, NM 87801 (United States); Morrison, G. E. [Institute for Astronomy, University of Hawaii, Honolulu, 96822 (United States)], E-mail: fowen@nrao.edu

2009-06-15T23:59:59.000Z

306

Magnetic spectroscopy and microscopy of functional materials  

SciTech Connect (OSTI)

Heusler intermetallics Mn{sub 2}Y Ga and X{sub 2}MnGa (X; Y =Fe, Co, Ni) undergo tetragonal magnetostructural transitions that can result in half metallicity, magnetic shape memory, or the magnetocaloric effect. Understanding the magnetism and magnetic behavior in functional materials is often the most direct route to being able to optimize current materials for todays applications and to design novel ones for tomorrow. Synchrotron soft x-ray magnetic spectromicroscopy techniques are well suited to explore the the competing effects from the magnetization and the lattice parameters in these materials as they provide detailed element-, valence-, and site-specifc information on the coupling of crystallographic ordering and electronic structure as well as external parameters like temperature and pressure on the bonding and exchange. Fundamental work preparing the model systems of spintronic, multiferroic, and energy-related compositions is presented for context. The methodology of synchrotron spectroscopy is presented and applied to not only magnetic characterization but also of developing a systematic screening method for future examples of materials exhibiting any of the above effects. The chapter progression is as follows: an introduction to the concepts and materials under consideration (Chapter 1); an overview of sample preparation techniques and results, and the kinds of characterization methods employed (Chapter 2); spectro- and microscopic explorations of X{sub 2}MnGa/Ge (Chapter 3); spectroscopic investigations of the composition series Mn{sub 2}Y Ga to the logical Mn{sub 3}Ga endpoint (Chapter 4); and a summary and overview of upcoming work (Chapter 5). Appendices include the results of a Think Tank for the Graduate School of Excellence MAINZ (Appendix A) and details of an imaging project now in progress on magnetic reversal and domain wall observation in the classical Heusler material Co{sub 2}FeSi (Appendix B).

Jenkins, C.A.

2011-01-28T23:59:59.000Z

307

2012 ELECTRONIC SPECTROSCOPY & DYNAMICS GORDON RESEARCH CONFERENCE, JULY 22-27, 2012  

SciTech Connect (OSTI)

Topics covered in this GRC include high-resolution spectroscopy, coherent electronic energy transport in biology, excited state theory and dynamics, excitonics, electronic spectroscopy of cold and ultracold molecules, and the spectroscopy of nanostructures. Several sessions will highlight innovative techniques such as time-resolved x-ray spectroscopy, frequency combs, and liquid microjet photoelectron spectroscopy that have forged stimulating new connections between gas-phase and condensed-phase work.

Kohler, Bern

2012-07-27T23:59:59.000Z

308

Synchrotron Radiation Photoemission Spectroscopic Study of Band Offsets and Interface Self-cleaning by Atomic Layer Deposited HfO2 on In0.53Ga0.47As and In0.52Al0.48As  

SciTech Connect (OSTI)

The Synchrotron Radiation Photoemission Spectroscopic (SRPES) study was conducted to (a) investigate the surface chemistry of In{sub 0.53}Ga{sub 0.47}As and In{sub 0.52}Al{sub 0.48}As post chemical and thermal treatments, (b) construct band diagram and (c) investigate the interface property of HfO{sub 2}/In{sub 0.53}Ga{sub 0.47}As and HfO{sub 2}/In{sub 0.52}Al{sub 0.48}As. Dilute HCl and HF etch remove native oxides on In{sub 0.53}Ga{sub 0.47}As and In{sub 0.52}Al{sub 0.47}As, whereas in-situ vacuum annealing removes surface arsenic pile-up. After the atomic layer deposition of HfO{sub 2}, native oxides were considerably reduced compared to that in as-received epi-layers, strongly suggesting the self-clean mechanism. Valence and conduction band offsets are measured to be 3.37 {+-} 0.1eV, 1.80 {+-} 0.3eV for In{sub 0.53}Ga{sub 0.47}As and 3.00 {+-} 0.1eV, 1.47 {+-} 0.3eV for In{sub 0.52}Al{sub 0.47}As, respectively.

Kobayashi, Masaharu; /SLAC, SSRL; Chen, P.T.; Sun, Y.; Goel, N.; Majhi, P.; Garner, M; Tsai, W.; Pianetta, P.; Nishi, Y.; /SLAC, SSRL

2008-10-31T23:59:59.000Z

309

Ion dip spectroscopy of cold molecules and ions. Progress report  

SciTech Connect (OSTI)

During the past year, the main emphasis in this research program has been on multiphoton ionization spectroscopy of aromatic clusters. This is being pursued in addition to continuing work in areas of ion dip spectroscopy and ion fragmentation spectroscopy. The program has the overall objective of developing improved ultrasensitive molecular detection methods based on multiphoton laser spectroscopy. Photoionization techniques are employed due to their extreme sensitivity combined with mass selectivity. The combination of these two features has led to the current capability to study molecular clusters of specific sizes with high spectral resolution. Clusters are formed in abundance in a supersonic expansion, where they are excited and ionized by an ultraviolet laser beam. The studies reported here are principally based on simple resonant excitation of clusters, followed by one-photon ionization. For the naphthalene clusters, a single laser wavelength suffices for both excitation steps. Additional investigations have been carried out to measure excited state cluster ionization spectra and cluster ion fragmentation spectra. Results from these measurements are not yet sufficiently advanced to report in detail, however the preliminary data support the importance of recently proposed new fundamental ionization mechanisms in clusters. This brief report summarizes results described in more detail in the preprint titled: Resonant two-photon ionization spectroscopy of naphthalene clusters and the preprint titled: Resonance interactions in naphthalene clusters. It also briefly describes preliminary undisclosed results of current investigations.

Wessel, J.E.

1988-08-23T23:59:59.000Z

310

Spectroscopy and reactions of vibrationally excited transient molecules  

SciTech Connect (OSTI)

Spectroscopy, energy transfer and reactions of vibrationally excited transient molecules are studied through a combination of laser-based excitation techniques and efficient detection of emission from the energized molecules with frequency and time resolution. Specifically, a Time-resolved Fourier Transform Emission Spectroscopy technique has been developed for detecting dispersed laser-induced fluorescence in the IR, visible and UV regions. The structure and spectroscopy of the excited vibrational levels in the electronic ground state, as well as energy relaxation and reactions induced by specific vibronic excitations of a transient molecule can be characterized from time-resolved dispersed fluorescence in the visible and UV region. IR emissions from highly vibrational excited levels, on the other hand, reveal the pathways and rates of collision induced vibrational energy transfer.

Dai, H.L. [Univ. of Pennsylvania, Philadelphia (United States)

1993-12-01T23:59:59.000Z

311

2010 GRC VIBRATIONAL SPECTROSCOPY AUGUST 1 - AUGUST 6, 2010  

SciTech Connect (OSTI)

The Vibrational Spectroscopy conference focuses on using vibrational spectroscopy to probe structure and dynamics of molecules in gases, liquids, and at interfaces. The conference explores the wide range of state-of-the-art techniques based on vibrational motion. These techniques span the fields of time-domain, high-resolution frequency-domain, spatially-resolved, nonlinear and multidimensional spectroscopies. The conference highlights the application of these techniques in chemistry, materials, biology, and medicine. The theory of molecular vibrational motion and its connection to spectroscopic signatures and chemical reaction dynamics is the third major theme of the meeting. The goal is to bring together a collection of researchers who share common interests and who will gain from discussing work at the forefront of several connected areas. The intent is to emphasize the insights and understanding that studies of vibrations provide about a variety of molecular systems ranging from small polyatomic molecules to large biomolecules and nanomaterials.

Brooks Pate

2010-08-06T23:59:59.000Z

312

Infrared absorption spectroscopy and chemical kinetics of free radicals  

SciTech Connect (OSTI)

This research is directed at the detection, monitoring, and study of chemical kinetic behavior by infrared absorption spectroscopy of small free radical species thought to be important intermediates in combustion. During the last year, infrared kinetic spectroscopy using excimer laser flash photolysis and color-center laser probing has been employed to study the high resolution spectrum of HCCN, the rate constant of the reaction between ethynyl (C{sub 2}H) radical and H{sub 2} in the temperature region between 295 and 875 K, and the recombination rate of propargyl (CH{sub 2}CCH) at room temperature.

Curl, R.F.; Glass, G.P. [Rice Univ., Houston, TX (United States)

1993-12-01T23:59:59.000Z

313

Spectroscopy and Decay of $B$ Hadrons at the Tevatron  

SciTech Connect (OSTI)

The authors review recent results on heavy quark physics focusing on Run II measurements of B hadron spectroscopy and decay at the Tevatron. A wealth of new B physics measurements from CDF and D0 has been available. These include the spectroscopy of excited B states (B**, B**{sub s}) and the observation of the {Sigma}{sub b} baryon. The discussion of the decays of B hadrons and measurements of branching fractions focuses on charmless two-body decays of B {yields} h{sup +}h{sup -}. They report several new B{sub s}{sup 0} and {Lambda}{sub b}{sup 0} decay channels.

Paulini, Manfred

2007-02-01T23:59:59.000Z

314

Multiplexed absorption tomography with calibration-free wavelength modulation spectroscopy  

SciTech Connect (OSTI)

We propose a multiplexed absorption tomography technique, which uses calibration-free wavelength modulation spectroscopy with tunable semiconductor lasers for the simultaneous imaging of temperature and species concentration in harsh combustion environments. Compared with the commonly used direct absorption spectroscopy (DAS) counterpart, the present variant enjoys better signal-to-noise ratios and requires no baseline fitting, a particularly desirable feature for high-pressure applications, where adjacent absorption features overlap and interfere severely. We present proof-of-concept numerical demonstrations of the technique using realistic phantom models of harsh combustion environments and prove that the proposed techniques outperform currently available tomography techniques based on DAS.

Cai, Weiwei; Kaminski, Clemens F., E-mail: cfk23@cam.ac.uk [Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB2 3RA (United Kingdom)

2014-04-14T23:59:59.000Z

315

Nanoscience on the Timescale of Electrons Ultrafast Spectroscopy of Nanomaterials  

E-Print Network [OSTI]

Nanoscience on the Timescale of Electrons Ultrafast Spectroscopy of Nanomaterials Pat Kambhampati with it??? ·How does it actually work??? #12;Nanoscience on the Ultrafast Timescale Pat Kambhampati, Mc? #12;Nanoscience on the Ultrafast Timescale Pat Kambhampati, McGill Chemistry Nanomaterial based

Kambhampati, Patanjali

316

Vibrational Raman Spectroscopy of High-temperature Superconductors  

E-Print Network [OSTI]

Vibrational Raman Spectroscopy of High-temperature Superconductors C. Thomsen and G. Kaczmarczyk-temperature Superconductors C. Thomsen and G. Kaczmarczyk Technical University of Berlin, Berlin, Germany 1 INTRODUCTION Raman after the discovery of high- critical-temperature Tc superconductors:2 while reports on Raman scattering

Nabben, Reinhard

317

Charm and Charmonium Spectroscopy in BaBar  

SciTech Connect (OSTI)

The BABAR experiment at the PEP-II B-factory offers excellent opportunities in charm and charmonium spectroscopy. The recent observation of new states in the D{sub s} and in the charmonium mass regions revived the interest in this field. Recent BABAR results are presented.

Negrini, M.; /Ferrara U.

2008-02-06T23:59:59.000Z

318

Journal of Quantitative Spectroscopy & Radiative Transfer 98 (2006) 220237  

E-Print Network [OSTI]

discontinuities associated with the propagation of a radiation front in transient radiation transport. r 2005 q heat flux s geometric path length S source term in the radiative transfer equation t time tc timeJournal of Quantitative Spectroscopy & Radiative Transfer 98 (2006) 220­237 Modified method

Pilon, Laurent

319

Journal of Quantitative Spectroscopy & Radiative Transfer 91 (2005) 2746  

E-Print Network [OSTI]

used in the field of transport phenomena simulation, and more specifically in the field of radiative (application of the reciprocity principle to the integral form of the radiative transfer equation), and to netJournal of Quantitative Spectroscopy & Radiative Transfer 91 (2005) 27­46 A boundary-based net

Dufresne, Jean-Louis

320

Instrumentation for Far-infrared Spectroscopy Peter R. Griffiths1  

E-Print Network [OSTI]

at one end with an infrared transparent window (A) through which radiation reaches a thin absorbing film- and Far-Infrared Spectroscopy Window Incident radiation A B Absorbing film Pneumatic chamber Ballasting passes through the window onto a blackened film, causing the pressure of the gas in the pneumatic chamber

Homes, Christopher C.

Note: This page contains sample records for the topic "angle-resolved photoemission spectroscopy" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Absorption spectroscopy of individual single-walled carbon nanotubes  

E-Print Network [OSTI]

Absorption spectroscopy of individual single-walled carbon nanotubes Stéphane Berciaud,a Laurent-walled carbon nanotubes (SWNTs) lead to heterogeneous samples containing mixtures of metallic and semiconducting species with a variety of lengths and defects. Optical detection at the single nanotube level should thus

Boyer, Edmond

322

Carbon nanotubes adhesion and nanomechanical behavior from peeling force spectroscopy  

E-Print Network [OSTI]

Carbon nanotubes adhesion and nanomechanical behavior from peeling force spectroscopy Julien December 17, 2010 Abstract Applications based on Single Walled Carbon Nanotube (SWNT) are good example such as adhesion energy per unit length, curvature and bending rigidity of the nanotube. A complete picture

Boyer, Edmond

323

Laser Locking with Doppler-free Saturated Absorption Spectroscopy  

E-Print Network [OSTI]

there are many ways to stabilize the frequency of a laser, atomic absorption lines are particularly accurate are made, it becomes possible to resolve the saturated absorption lines that correspond to specific atomic absorption spectroscopy. This affects the number of atoms in the ground state and excited state

Novikova, Irina

324

Transient x-ray absorption spectroscopy of hydrated halogen atom  

E-Print Network [OSTI]

Time-resolved x-ray absorption spectroscopy has been used to observe the transient species generated by one-photon detachment of an electron from aqueous bromide. The K-edge spectrum of the short-lived Br(0) atom exhibits a resonant 1s-4p transition...

Elles, Christopher G.; Shkrob, Ilya A.; Crowell, Robert A.; Arms, Dohn A.; Landahl, Eric C.

2008-02-11T23:59:59.000Z

325

ENERGY LEVEL SPECTROSCOPY OF A BOUND VORTEX-ANTIVORTEX PAIR  

E-Print Network [OSTI]

vortex- antivortex (VAV) state in an annular Josephson junction. The bound VAV pair is formed microwave spectroscopy. Keywords: Macroscopic quantum effects, long Josephson junctions, vortex­9]. Most of the studied systems, such as dc-biased Josephson junctions (JJ), supercon- ducting quantum

Wallraff, Andreas

326

Use of gamma spectroscopy for neutronic analysis of LMFBR Blankets  

E-Print Network [OSTI]

It was the purpose of the present investigation to extend and apply Ge(Li) gamma-ray spectroscopy to the study of fast reactor blankets. The focal point for this research was the Blanket Test Facility at the MITR and Blanket ...

Kang, Ch?ang-sun

327

Application of nanoporous silicon substrates for terahertz spectroscopy  

E-Print Network [OSTI]

molecule," Spectrochim. Acta 61, 2741­2746 (2005). 4. M. Kutteruf, C. Brown, L. Iwaki, M. Campbell, T 1. M. van Exter, C. Fattinger, and D. Grischkowsky, "Terahertz time-domain spectroscopy of water acid molecule," J. Raman Spectrosc. 14, 347­352 (1983). 7. E. J. Heilweil and D. F. Plusquellic

Murphy, Thomas E.

328

Proton Ordering of Cubic Ice Ic: Spectroscopy and Computer Simulations  

E-Print Network [OSTI]

by producing rotational Bjerrum L-defects.1 Ambient-pressure hexagonal ice, ice Ih, shows the lowest produced from ice Ih using hydroxide doping, for example, by freezing a 0.1 M KOH solution. Because ice IhProton Ordering of Cubic Ice Ic: Spectroscopy and Computer Simulations Philipp Geiger, Christoph

Dellago, Christoph

329

Human brain cancer studied by resonance Raman spectroscopy  

E-Print Network [OSTI]

Human brain cancer studied by resonance Raman spectroscopy Yan Zhou Cheng-Hui Liu Yi Sun Yang Pu://biomedicaloptics.spiedigitallibrary.org/ on 11/16/2012 Terms of Use: http://spiedl.org/terms #12;Human brain cancer studied by resonance Raman of human brain tissues are examined using a confocal micro-Raman system with 532-nm excitation in vitro

Sun, Yi

330

Postdoc Position in Microfluidics and Single Cell Raman Spectroscopy  

E-Print Network [OSTI]

Postdoc Position in Microfluidics and Single Cell Raman Spectroscopy Department of Microbial and Environmental Microfluidics Group (http://web.mit.edu/romanstocker) Department of Civil & Environmental (junior or senior) with strong expertise in microfluidics and an interest in applying it to microbial

Horn, Matthias

331

TIME-RESOLVED TERAHERTZ TRANSMISSION SPECTROSCOPY OF DIELECTRICS  

E-Print Network [OSTI]

semiconductor surfaces in bulk semiconductor wafers[5,6,7], etc. The detection techniques which are based in fact constitutes a bridge between the classical IR spectroscopy domain and the frequencies accessible polar excitations in optical materials like sapphire and quartz[15], in semiconductors (Ge, GaAs, Si

Ku?el, Petr

332

Laser photothermal spectroscopy of light-induced absorption  

SciTech Connect (OSTI)

Basic methods of laser photothermal spectroscopy, which are used to study photoinduced absorption in various media, are briefly considered. Comparative analysis of these methods is performed and the latest results obtained in this field are discussed. Different schemes and examples of their practical implementation are considered. (review)

Skvortsov, L A [Institute of Cryptography, Communications and Informatics, Moscow (Russian Federation)

2013-01-31T23:59:59.000Z

333

New Frontiers in Solar Physics: Broadband Imaging Spectroscopy with the  

E-Print Network [OSTI]

, the solar panel of the AASC recommended an integrated suite of instrumentation designed to meetNew Frontiers in Solar Physics: Broadband Imaging Spectroscopy with the Frequency Agile Solar and other astrophysical objects and processes. Outstanding problems in solar physics include the magnetic

334

Photoelectron spectroscopy of solvated electrons in alcohol and acetonitrile microjets  

E-Print Network [OSTI]

Photoelectron spectroscopy of solvated electrons in alcohol and acetonitrile microjets Alexander T in methanol, ethanol, and acetonitrile microjets are reported. Solvated electrons are generated. Two features are observed in acetonitrile at 2.61 Ã? 0.11 eV and 3.67 Ã? 0.15 eV, attributed

Neumark, Daniel M.

335

Skin cancer detection by oblique-incidence diffuse reflectance spectroscopy  

E-Print Network [OSTI]

Skin cancer is the most common form of cancer and it is on the rise. If skin cancer is diagnosed early enough, the survival rate is close to 90%. Oblique-incidence diffuse reflectance (OIR) spectroscopy offers a technology that may be used...

Smith, Elizabeth Brooks

2009-05-15T23:59:59.000Z

336

Laser and Spectroscopy Facility Center For Microanalysis of Materials  

E-Print Network [OSTI]

Laser and Spectroscopy Facility Center For Microanalysis of Materials Frederick Seitz Materials Research Laboratory Form revised 03 November 2009 Precautions for the safe use of lasers 1. NEVER LOOK DIRECTLY INTO ANY LASER BEAM, REGARDLESS OF POWER. 2. The lab door safety lamp "LASER in USE" must

Braun, Paul

337

Time resolved ultraviolet absorption spectroscopy of pulsed fluorocarbon plasmas  

E-Print Network [OSTI]

Time resolved ultraviolet absorption spectroscopy of pulsed fluorocarbon plasmas Brett A. Cruden.1063/1.1334936 I. INTRODUCTION The study of fluorocarbon plasmas is of great interest for their applications in silicon dioxide etching.1,2 Recently, at- tention has been paid to using fluorocarbon plasmas to pro- duce

Gleason, Karen K.

338

X-Ray Photoelectron Spectroscopy XPS Mark Engelhard  

E-Print Network [OSTI]

X-Ray Photoelectron Spectroscopy XPS Mark Engelhard 1 #12;EMSL XPS Instrumentation 2 Physical Electronics Quantera XPS High Energy Resolution Focused X-ray Beam Capability Catalysis reaction and processing chamber with inert atmosphere glove box connected to a PHI Quantera Scanning X-ray Microprobe

339

absorption spectroscopy xas: Topics by E-print Network  

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

absorption spectroscopy xas First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Time Resolved X-Ray...

340

absorption spectroscopy studies: Topics by E-print Network  

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

absorption spectroscopy studies First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 On Automatic Absorption...

Note: This page contains sample records for the topic "angle-resolved photoemission spectroscopy" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Journal of Quantitative Spectroscopy & Radiative Transfer 99 (2006) 341348  

E-Print Network [OSTI]

structure on non-LTE, non-diffusive radiation transport and X-ray production is discussed. r 2005 Elsevier Ltd. All rights reserved. Keywords: Z-pinch plasma; K-shell X-ray production and spectroscopy; Opacity tungsten wires [2]. Strong j  B forces implode the wire array, which generates nearly 2 MJ of X-rays in o

2006-01-01T23:59:59.000Z

342

E-Print Network 3.0 - auger spectroscopy studies Sample Search...  

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

Spectroscopy Analytical technique used in the study of surfaces... V and 15mA emission (3-5 times,20min interval) Flash heating the sample for 2 min. Auger Spectroscopy......

343

Tip-Enhanced Near-Field Raman Spectroscopy Probing Single Dye...  

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

Tip-Enhanced Near-Field Raman Spectroscopy Probing Single Dye-Sensitized TiO2 Nanoparticles. Tip-Enhanced Near-Field Raman Spectroscopy Probing Single Dye-Sensitized TiO2...

344

E-Print Network 3.0 - andreev reflection spectroscopy Sample...  

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

1 Andreev-level spectroscopy and Josephson-current switching in a three-terminal Josephson junction Summary: Andreev-level spectroscopy and Josephson-current switching in a...

345

E-Print Network 3.0 - absorption spectroscopy Sample Search Results  

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

.619 nm Calculate the energy of the photon: h 1.633 aJ Absorption Spectroscopy In absorption... Atomic Spectroscopy Planck's constant: h 6.62608 10 34- joule sec: Speed of...

346

E-Print Network 3.0 - atomic emission spectroscopy Sample Search...  

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

Spectroscopy of an Atomic Nucleus: The Thorium-229 Nuclear Clock Dr... spectroscopy of an atomic nucleus. Host: Mansoor Sheik-Bahae 12;... of 7.6 0.5 eV. This makes it...

347

E-Print Network 3.0 - absorption spectroscopy q-xas Sample Search...  

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

.619 nm Calculate the energy of the photon: h 1.633 aJ Absorption Spectroscopy In absorption... Atomic Spectroscopy Planck's constant: h 6.62608 10 34- joule sec: Speed of...

348

USE OF ZEEMAN ATOMIC ABSORPTION SPECTROSCOPY FOR THE MEASUREMENT OF MERCURY IN OIL SHALE GASES  

E-Print Network [OSTI]

Isotope Zeeman Atomic Absorption; A new approach to chemical6782 Use of Zeeman Atomic Absorption Spectroscopy for theb:l r I USE OF ZEEMAN ATOMIC ABSORPTION SPECTROSCOPY FOR THE

Girvin, D.G.

2011-01-01T23:59:59.000Z

349

Measurement of uranium enrichment by gamma spectroscopy: result of an experimental design  

E-Print Network [OSTI]

, Gamma Spectrometry, uranium enrichment #12;PAPER Measurement of uranium enrichment by gamma spectroscopy: result of an experimental design Gamma spectroscopy is commonly used in nuclear safeguards to measure uranium enrichment. An experimental

350

Thermal infrared emission spectroscopy of titanium-enriched V. E. Hamilton  

E-Print Network [OSTI]

Thermal infrared emission spectroscopy of titanium-enriched pyroxenes V. E. Hamilton Hawai, Angra dos Reis, remote sensing Citation: Hamilton, V. E., Thermal infrared emission spectroscopy [Lyon, 1962], and emission [Hamilton, 1998, 2000] spectroscopic studies. These studies have documented

Hamilton, Victoria E.

351

E-Print Network 3.0 - angular correlation spectroscopy Sample...  

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

80 Level-crossing spectroscopy of the 7, 9, and 10D states of Cs in an external electric field Summary: 's angular momentum. Keywords: Level-crossing spectroscopy, alignment...

352

X-ray Absorption Spectroscopy Study of Prototype Chemical Systems: Theory vs. Experiment  

E-Print Network [OSTI]

acids by Near Edge X-ray Absorption Fine Structure (NEXAFS)X-ray Absorption Spectroscopy Study of Prototype ChemicalGlaeser Spring 2010 X-ray Absorption Spectroscopy Study of

Schwartz, Craig Philip

2010-01-01T23:59:59.000Z

353

X-ray absorption spectroscopy at the Ni-K edge in Stackhousia tryonii Bailey hyperaccumulator  

E-Print Network [OSTI]

X-ray absorption spectroscopy at the Ni–K edge inin vivo by micro x-ray absorption spectroscopy (XAS) at theNi–K edge. Both x-ray absorption near edge structure and

Kachenko, A.

2009-01-01T23:59:59.000Z

354

Questioning the questions that have been asked about the infant brain using near-infrared spectroscopy  

E-Print Network [OSTI]

Questioning the questions that have been asked about the infant brain using near-infrared, University of Rochester, Rochester, NY, USA Near-infrared spectroscopy (NIRS) is a noninvasive diffuse; Near-infrared spectroscopy. "Sheddinglight"onascientificquestiontookonnew meaning when

Aslin, Richard N.

355

Development of multimodal spectroscopy for the detection of vulnerable atherosclerotic plaques  

E-Print Network [OSTI]

The combination of reflectance, fluorescence, and Raman spectroscopy - which is termed multimodal spectroscopy (MMS) - provides complementary and depth-sensitive information about tissue composition. As such, MMS can provide ...

Š?epanovi?, Obrad R., 1980-

2008-01-01T23:59:59.000Z

356

Development of High-Throughput Microfluidic Impedance Spectroscopy Platform for Analyzing Microdroplets in Droplet Microfluidic System  

E-Print Network [OSTI]

This thesis presents the development of a high-throughput microfluidic impedance spectroscopy platform for electrically detecting analyzing impedance measurements of non-contact and label free microdroplets. This microfluidic impedance spectroscopy...

Sobahi, Nebras MohammedKamal A.

2014-07-22T23:59:59.000Z

357

Protein Characterisation by Synchrotron Radiation Circular Dichroism (SRCD) Spectroscopy  

SciTech Connect (OSTI)

Circular dichroism (CD) spectroscopy is a well-established technique for the study of proteins. Synchrotron radiation circular dichroism (SRCD) spectroscopy extends the utility of conventional CD spectroscopy (i.e. using laboratory-based instruments) because the high light flux from a synchrotron enables collection of data to lower wavelengths, detection of spectra with higher signal-to-noise levels and measurements in the presence of strongly absorbing non-chiral components such as salts, buffers, lipids and detergents. This review describes developments in instrumentation, methodologies and bioinformatics that have enabled new applications of the SRCD technique for the study of proteins. It includes examples of the use of SRCD spectroscopy for providing static and dynamic structural information on molecules, including determinations of secondary structures of intact proteins and domains, assessment of protein stability, detection of conformational changes associated with ligand and drug binding, monitoring of environmental effects, examination of the processes of protein folding and membrane insertion, comparisons of mutant and modified proteins, identification of intermolecular interactions and complex formation, determination of the dispositions of proteins in membranes, identification of natively disordered proteins and their binding partners and examination of the carbohydrate components of glycoproteins. It also discusses how SRCD can be used in conjunction with macromolecular crystallography and other biophysical techniques to provide a more complete picture of protein structures and functions, including how proteins interact with other macromolecules and ligands. This review also includes a discussion of potential new applications in structural and functional genomics using SRCD spectroscopy and future instrumentation and bioinformatics developments that will enable such studies. Finally, the appendix describes a number of computational/bioinformatics resources for secondary structure analyses that take advantage of the improved data quality available from SRCD. In summary, this review discusses how SRCD can be used for a wide range of structural and functional studies of proteins.

Wallace, B.

2009-01-01T23:59:59.000Z

358

E-Print Network 3.0 - ablation mass spectroscopy Sample Search...  

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

implants into rat livers after radiofrequency ablation were quantified by atomic absorption spectroscopy... Local carboplatin delivery and tissue distribution in...

359

E-Print Network 3.0 - atomic fluorescence spectroscopy Sample...  

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

total reflectance... increasing. A partial sampling of these techniques includes: Absorption spectroscopy Atomic ... Source: Yucca Mountain Project, US EPA Collection:...

360

Ion dip spectroscopy of cold molecules and ions. Progress report and renewal proposal  

SciTech Connect (OSTI)

A research program is underway with the objective of developing techniques of high resolution multiphoton spectroscopy for selective, ultrasensitive molecular detection. Methods under study include various forms of ion dip spectroscopy and new methods of ion fragmentation spectroscopy. The studies are providing a new understanding of the fundamental spectroscopy and photophysics of large molecular ions. Dimer and cluster ions of polynuclear aromatics and related species are also being investigated, with potential detection applications.

Wessel, J.

1987-08-13T23:59:59.000Z

Note: This page contains sample records for the topic "angle-resolved photoemission spectroscopy" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Determination of Tellurium by Atomic-absorption Spectroscopy with Electrothermal Atomisation  

E-Print Network [OSTI]

305 Determination of Tellurium by Atomic-absorption Spectroscopy with Electrothermal Atomisation at sub-microgram levels by atomic-absorption spectroscopy ,,'ith electrothermal atomisation after the e generation -atomic-absorption spectroscopy. The prior con- version of tellurium into hydrogen telluride

Canberra, University of

362

Infrared Spectroscopy of the Microhydrated Nitrate Ions NO3 Daniel J. Goebbert,,  

E-Print Network [OSTI]

Infrared Spectroscopy of the Microhydrated Nitrate Ions NO3 - (H2O)1-6 Daniel J. Goebbert ReceiVed: April 15, 2009 We present infrared photodissociation spectra of the microhydrated nitrate ions the infrared spectroscopy of NO3 - (H2O)n clusters, n ) 1-6. The gas-phase vibrational spectroscopy of NO3

Neumark, Daniel M.

363

Coded Aperture Raman Spectroscopy for Quantitative Measurements of Ethanol in a Tissue Phantom  

E-Print Network [OSTI]

- mard transform spectroscopy'' (HTS).9 Initially, HTS systems were designed to use multiplexing tissue phantom. With 60 mW of excitation power at 808 nm, leave-one-out and blind cross spectroscopy; Multiplexing; Chemometrics. INTRODUCTION Raman spectroscopy is a powerful diagnostic tool

Pitsianis, Nikos P.

364

Human-Computer Interaction and Brain Measurement Using Functional Near-Infrared Spectroscopy  

E-Print Network [OSTI]

Human-Computer Interaction and Brain Measurement Using Functional Near-Infrared Spectroscopy Leanne Functional near-infrared spectroscopy (fNIRS) is an emerging non-invasive, lightweight imaging tool which can remains a challenge. We investigate functional near-infrared spectroscopy (fNIRS) [1], a relatively new

Jacob, Robert J.K.

365

Speciation and spectroscopy of the uranyl and tetravalent plutonium nitrate systems: Fundamental studies and applications to used fuel reprocessing.  

E-Print Network [OSTI]

??This dissertation explores the use of UV-Visible spectroscopy and Time Resolved Laser Induced Fluorescence spectroscopy as near real time process monitors of uranium and plutonium… (more)

Smith, Nicholas A

2010-01-01T23:59:59.000Z

366

Sum Frequency Generation Vibrational Spectroscopy of Adsorbed Amino Acids, Peptides, and Proteins at Hydrophilic and Hydrophobic Solid-Water Interfaces  

E-Print Network [OSTI]

Chapter 2 Sum Frequency Generation Vibrational Spectroscopy2.1. Sum Frequency Generation Vibrational SpectroscopyIntroduction Sum frequency generation (SFG) vibrational

Holinga, George J.

2010-01-01T23:59:59.000Z

367

Adsorption of acetonitrile (CH{sub 3}CN) on Si(111)-7x7 at room temperature studied by synchrotron radiation core-level spectroscopies and excited-state density functional theory calculations  

SciTech Connect (OSTI)

The room temperature adsorption of acetonitrile (CH{sub 3}-C{identical_to}N) on Si(111)-7x7 is examined by synchrotron radiation N 1s x-ray photoemission and x-ray absorption spectroscopies. The experimental spectroscopic data point to multiple adsorption geometries. Candidate structures are optimized using density functional theory (DFT), the surface being simulated by silicon clusters encompassing one (adjacent) adatom-rest atom pair. This is followed by the DFT calculation of electron transition energies and cross sections. The comparison of theoretical spectra with experimental ones indicates that the molecule is adsorbed on the surface under two forms, a nondissociated geometry (an sp{sup 2}-hybridized CN) and a dissociated one (leading to a pendent sp-hybridized CN). In the nondissociative mode, the molecule bridges an adatom-rest atom pair. For bridge-type models, the discussion of the core-excited state calculations is focussed on the so-called silicon-molecule mixed-state transitions that strongly depend on the breaking or not of the adatom backbonds and on the attachment of the nitrogen end either to the adatom or to the rest atom. Concerning the dissociated state, the CH bond cleavage leads to a cyanomethyl (Si-CH{sub 2}-CN) plus a silicon monohydride, which accounts for the spectroscopic evidence of a free C{identical_to}N group (we do not find at 300 K any spectroscopic evidence for a C{identical_to}N group datively bonded to a silicon atom via its nitrogen lone pair). Therefore the reaction products of acetonitrile on Si(111)-7x7 are similar to those detected on the Si(001)-2x1 surface at the same temperature, despite the marked differences in the reconstruction of those two surfaces, especially the distance between adjacent silicon broken bonds. In that respect, we discuss how adatom backbond breaking in the course of adsorption may explain why both surface orientations react the same way with acetonitrile.

Bournel, F.; Carniato, S.; Dufour, G.; Gallet, J.-J.; Ilakovac, V.; Rangan, S.; Rochet, F.; Sirotti, F. [Laboratoire de Chimie Physique Matiere et Rayonnement, Universite Pierre et Marie Curie, 11 rue Pierre et Marie Curie, 75231 Paris Cedex 05 (France); Synchrotron SOLEIL, L'Orme des Merisiers Saint-Aubin, Boite Postale 48, 91192 Gif sur Yvette Cedex (France)

2006-03-15T23:59:59.000Z

368

Applications of laser-induced gratings to spectroscopy and dynamics  

SciTech Connect (OSTI)

This program has traditionally emphasized two principal areas of research. The first is the spectroscopic characterization of large-amplitude motion on the ground-state potential surface of small, transient molecules. The second is the reactivity of carbonaceous clusters and its relevance to soot and fullerene formation in combustion. Motivated initially by the desire to find improved methods of obtaining stimulated emission pumping (SEP) spectra of transients, most of our recent work has centered on the use of laser-induced gratings or resonant four-wave mixing in free-jet expansions. These techniques show great promise for several chemical applications, including molecular spectroscopy and photodissociation dynamics. The author describes recent applications of two-color laser-induced grating spectroscopy (LIGS) to obtain background-free SEP spectra of transients and double resonance spectra of nonfluorescing species, and the use of photofragment transient gratings to probe photodissociation dynamics.

Rohlfing, E.A. [Sandia National Laboratories, Livermore, CA (United States)

1993-12-01T23:59:59.000Z

369

Report of the Study Group on Complete Spectroscopy  

SciTech Connect (OSTI)

This report summarizes the topics considered in four discussions of about two hours each attended by most of the workshop participants. The contents of the lectures of David Radford, Fumihiko Sakata, Ben Mottelson, and Jerry Garret pertaining to Complete Spectroscopy are contained elsewhere in this proceedings. Most detailed nuclear structure information is derived from measurements of the spectroscopic properties (e.g. excitation energies, angular momenta, parities, lifetimes, magnetic moments, population cross sections, methods of decay, etc.) of discrete nuclear eigenstates. The present instrumentation allows in the best cases such measurements to approach the angular momentum limit imposed by fission and to as many as fifteen different excited bands. In anticipation of the new generation of detection equipment, such as the EUROBall and the GAMMASPHERE, the Complete Spectroscopy Study Group attempted to define the limits to such studies imposed by physical considerations and to consider some of the new, interesting physics that can be addressed from more complete discrete spectroscopic studies. 28 refs.

Garrett, J.D.

1989-01-01T23:59:59.000Z

370

Cone penetrometer fiber optic raman spectroscopy probe assembly  

DOE Patents [OSTI]

A chemically and mechanically robust optical Raman spectroscopy probe assembly that can be incorporated in a cone penetrometer (CPT) for subsurface deployment. This assembly consists of an optical Raman probe and a penetrometer compatible optical probe housing. The probe is intended for in-situ chemical analysis of chemical constituents in the surrounding environment. The probe is optically linked via fiber optics to the light source and the detection system at the surface. A built-in broadband light source provides a strobe method for direct measurement of sample optical density. A mechanically stable sapphire window is sealed directly into the side-wall of the housing using a metallic, chemically resistant, hermetic seal design. This window permits transmission of the interrogation light beam and the resultant signal. The spectroscopy probe assembly is capable of accepting Raman, Laser induced Fluorescence, reflectance, and other optical probes with collimated output for CPT deployment.

Kyle, Kevin R. (Brentwood, CA); Brown, Steven B. (Livermore, CA)

2000-01-01T23:59:59.000Z

371

Photodissociation spectroscopy and dynamics of free radicals, clusters, and ions  

SciTech Connect (OSTI)

The photodissociation spectroscopy and dynamics of free radicals and ions is studied to characterize the dissociative electronic states in these species. To accomplish this, a special method of radical production, based on the photodetachment of the corresponding negative ion, has been combined with the technique of fast beam photofragment translational spectroscopy. The photofragment yield as a function of photon energy is obtained, mapping out the dissociative and predissociative electronic states. Branching ratios to various product channels, the translational energy distributions of the fragments, and bond dissociation energies are then determined at selected photon energies. The detailed picture of photodissociation dynamics is provided with the aid of ab initio calculations and a statistical model to interpret the observed data. Important reaction intermediates in combustion reactions have been studied: CCO, C{sub 2}H{sub 5}O, and linear C{sub n} (n = 4--6).

Hyeon, Choi

1999-12-16T23:59:59.000Z

372

Method and apparatus for two-dimensional spectroscopy  

DOE Patents [OSTI]

Preferred embodiments of the invention provide for methods and systems of 2D spectroscopy using ultrafast, first light and second light beams and a CCD array detector. A cylindrically-focused second light beam interrogates a target that is optically interactive with a frequency-dispersed excitation (first light) pulse, whereupon the second light beam is frequency-dispersed at right angle orientation to its line of focus, so that the horizontal dimension encodes the spatial location of the second light pulse and the first light frequency, while the vertical dimension encodes the second light frequency. Differential spectra of the first and second light pulses result in a 2D frequency-frequency surface equivalent to double-resonance spectroscopy. Because the first light frequency is spatially encoded in the sample, an entire surface can be acquired in a single interaction of the first and second light pulses.

DeCamp, Matthew F. (Swarthmore, PA); Tokmakoff, Andrei (Lexington, MA)

2010-10-12T23:59:59.000Z

373

Chemometrics applied to vibrational spectroscopy: overview, challenges and pitfalls  

SciTech Connect (OSTI)

Chemometric multivariate calibration methods are rapidly impacting quantitative infrared spectroscopy in many positive ways. The combination of vibrational spectroscopy and chemometrics has been used by industry for quality control and process monitoring. The growth of these methods has been phenomenal in the past decade. Yet, as with any new technology, there are growing pains. The methods are so powerful at finding correlations in the data, that when used without great care they can readily yield results that are not valid for the analysis of future unknown samples. In this paper, the power of the multivariate calibration methods is discussed while pointing out common pitfalls and some remaining challenges that may slow the implementation of chemometrics in research and industry.

Haaland, D.M.

1996-10-01T23:59:59.000Z

374

Free-Electron Laser-Powered Electron Paramagnetic Resonance Spectroscopy  

E-Print Network [OSTI]

Electron paramagnetic resonance (EPR) spectroscopy interrogates unpaired electron spins in solids and liquids to reveal local structure and dynamics; for example, EPR has elucidated parts of the structure of protein complexes that have resisted all other techniques in structural biology. EPR can also probe the interplay of light and electricity in organic solar cells and light-emitting diodes, and the origin of decoherence in condensed matter, which is of fundamental importance to the development of quantum information processors. Like nuclear magnetic resonance (NMR), EPR spectroscopy becomes more powerful at high magnetic fields and frequencies, and with excitation by coherent pulses rather than continuous waves. However, the difficulty of generating sequences of powerful pulses at frequencies above 100 GHz has, until now, confined high-power pulsed EPR to magnetic fields of 3.5 T and below. Here we demonstrate that ~1 kW pulses from a free-electron laser (FEL) can power a pulsed EPR spectrometer at 240 GHz...

Takahashi, S; Edwards, D T; van Tol, J; Ramian, G; Han, S; Sherwin, M S

2012-01-01T23:59:59.000Z

375

Frequency Modulation Spectroscopy Modeling for Remote Chemical Detection  

SciTech Connect (OSTI)

Frequency modulation (FM) spectroscopy techniques show promise for active infrared remote chemical sensing. FM spectroscopy techniques have reduced sensitivity to optical and electronic noise, and are relatively immune to the effects of various electronic and mechanical drifts. FM systems are responsive to sharp spectral features and can therefore reduce the effects of spectral clutter due to interfering chemicals in the plume or in the atmosphere. The relatively high modulation frequencies used for FM also reduces the effects of albedo (reflectance) and plume variations. Conventional differential absorption lidar (DIAL) systems are performance limited by the noise induced by speckle. Analysis presented in this report shows that FM based sensors may reduce the effects of speckle by one to two orders of magnitude. This can result in reduced dwell times and faster area searches, as well as reducing various forms of spatial clutter. FM systems will require a laser system that is continuously tunable at relatively high frequencies (0.1 to 20 MHz). One promising candidate is the quantum-cascade (QC) laser [1, 2]. The QC laser is potentially capable of power levels on the order of 1 Watt and frequency tuning on the order of 3 - 6 GHz, which is the performance level required for FM spectroscopy based remote sensing. In this report we describe a high-level numerical model for an FM spectroscopy based remote sensing system, and application to two unmanned airborne vehicle (UAV) scenarios. A Predator scenario operating at a slant range of 6.5 km with a 10 cm diameter telescope, and a Global Hawk scenario operating at a range of 30 km with a 20 cm diameter telescope, has been assumed to allow estimation of the performance of potential FM systems.

Sheen, David M.

2000-09-30T23:59:59.000Z

376

Laser-induced breakdown spectroscopy for specimen analysis  

DOE Patents [OSTI]

The present invention is directed to an apparatus, a system and a method for detecting the presence or absence of trace elements in a biological sample using Laser-Induced Breakdown Spectroscopy. The trace elements are used to develop a signature profile which is analyzed directly or compared with the known profile of a standard. In one aspect of the invention, the apparatus, system and method are used to detect malignant cancer cells in vivo.

Kumar, Akshaya; Yu-Yueh, Fang; Burgess, Shane C.; Singh, Jagdish P.

2006-08-15T23:59:59.000Z

377

Sapphire analyzers for high-resolution x-ray spectroscopy.  

SciTech Connect (OSTI)

We present a sapphire (Al{sub 2}O{sub 3}) analyzer for high-resolution X-ray spectroscopy with 31-meV energy resolution. The analyzer is designed for resonant inelastic X-ray scattering (RIXS) measurements at the CuK{sub a} absorption edge near 8990 eV. The performance of the analyzer is demonstrated by measuring phonon excitations in beryllium because of its known dynamical structure and high counting rates.

Yavas, H.; Alp, E.; Sinn, H.; Alatas, A.; Said, A.; Shvydko, Y.; Toellner, T.; Khachatryan, R.; Billinge, S.; Hasan, Z.; Sturhahn, W.; Michigan State Univ.; Princeton Univ.; DESY

2007-11-11T23:59:59.000Z

378

Beam line design for synchrotron spectroscopy in the VUV  

SciTech Connect (OSTI)

The character of the radiation source provided by an electron storage ring is briefly reviewed from the point of view of utilization for VUV spectroscopy. The design of beam line components is then considered with special reference to the problems of contamination of optical surfaces and vacuum protection. The issues involved in designing mirrors for use with storage rings are considered with emphasis on the questions of power dissipation, image quality and materials selection.

Howells, M R

1980-01-01T23:59:59.000Z

379

A tool for phase resolved spectroscopy with ISGRI  

E-Print Network [OSTI]

INTEGRAL observations provide a large amount of data on accreting binary systems. The interpretation of the spectral emission of these sources needs timing analysis and phase resolved spectroscopy, which are really cumbersome tasks if performed with tools based on the imaging extraction methods usually used for coded mask instruments. Here we present a software for the ISGRI instrument which allows to extract in a fast way, light curves, pulse profiles, and phase resolved spectra, making data reduction a much easier task.

A. Segreto; C. Ferrigno

2007-09-26T23:59:59.000Z

380

Chemometric Analysis of Nuclear Magnetic Resonance Spectroscopy Data  

SciTech Connect (OSTI)

Chemometric analysis of nuclear magnetic resonance (NMR) spectroscopy has increased dramatically in recent years. A variety of different chemometric techniques have been applied to a wide range of problems in food, agricultural, medical, process and industrial systems. This article gives a brief review of chemometric analysis of NMR spectral data, including a summary of the types of mixtures and experiments analyzed with chemometric techniques. Common experimental problems encountered during the chemometric analysis of NMR data are also discussed.

ALAM,TODD M.; ALAM,M. KATHLEEN

2000-07-20T23:59:59.000Z

Note: This page contains sample records for the topic "angle-resolved photoemission spectroscopy" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Laser produced plasma diagnostics by cavity ringdown spectroscopy and applications  

SciTech Connect (OSTI)

Laser-produced plasmas have many applications for which detailed characterization of the plume is requested. Cavity ring-down spectroscopy is a versatile absorption method which provides data on the plume and its surroundings, with spatial and temporal resolution. The measured absorption line shapes contain information about angular and velocity distributions within the plume. In various plasmas we have observed molecules or metastable atoms which were not present in the emission spectra.

Milosevic, S. [Institute of Physics, Zagreb (Croatia)

2012-05-25T23:59:59.000Z

382

Investigation of Peptide Folding by Nuclear Magnetic Resonance Spectroscopy  

E-Print Network [OSTI]

Beta Alpha 5 Trpzip4 Tryptophan Zipper Peptide 4 16-DSA 16-DoxylStearic Acid 5-DSA 5-DoxylStearic Acid SDS Sodium Dodecyl Sulfate DPC DodecylPhosphoCholine CD Circular Dichroism Spectroscopy Gd-DTPA N...M 16-DSA and b) 4 mM Gd-DTPA ........................................................... 49 2.16 Comparison of finger print region of TOCSY spectra of individual peptide and mixture sample in a) 70% TFE and b) 100% TFE...

Hwang, SoYoun

2012-07-16T23:59:59.000Z

383

Nanoscale NMR Spectroscopy and Imaging of Multiple Nuclear Species  

E-Print Network [OSTI]

Nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) are well-established techniques that provide valuable information in a diverse set of disciplines but are currently limited to macroscopic sample volumes. Here we demonstrate nanoscale NMR spectroscopy and imaging under ambient conditions of samples containing multiple nuclear species, using nitrogen-vacancy (NV) colour centres in diamond as sensors. With single, shallow NV centres in a diamond chip and samples placed on the diamond surface, we perform NMR spectroscopy and one-dimensional MRI on few-nanometre-sized samples containing $^1$H and $^{19}$F nuclei. Alternatively, we employ a high-density NV layer near the surface of a diamond chip to demonstrate wide-field optical NMR spectroscopy of nanoscale samples containing $^1$H, $^{19}$F, and $^{31}$P nuclei, as well as multi-species two-dimensional optical MRI with sub-micron resolution. For all diamond samples exposed to air, we identify a ubiquitous $^1$H NMR signal, consistent with a $\\sim 1$ nm layer of adsorbed hydrocarbons or water on the diamond surface and below any sample placed on the diamond. This work lays the foundation for nanoscale NMR and MRI applications such as studies of single proteins and functional biological imaging with subcellular resolution, as well as characterization of thin films with sub-nanometre resolution.

Stephen J. DeVience; Linh M. Pham; Igor Lovchinsky; Alexander O. Sushkov; Nir Bar-Gill; Chinmay Belthangady; Francesco Casola; Madeleine Corbett; Huiliang Zhang; Mikhail Lukin; Hongkun Park; Amir Yacoby; Ronald L. Walsworth

2014-06-12T23:59:59.000Z

384

Seventh international conference on time-resolved vibrational spectroscopy  

SciTech Connect (OSTI)

The International Conference on Time-Resolved Vibrational Spectroscopy (TRVS) is widely recognized as the major international forum for the discussion of advances in this rapidly growing field. The 1995 conference was the seventh in a series that began at Lake Placid, New York, 1982. Santa Fe, New Mexico, was the site of the Seventh International Conference on Time-Resolved Vibrational Spectroscopy, held from June 11 to 16, 1995. TRVS-7 was attended by 157 participants from 16 countries and 85 institutions, and research ranging across the full breadth of the field of time-resolved vibrational spectroscopy was presented. Advances in both experimental capabilities for time-resolved vibrational measurements and in theoretical descriptions of time-resolved vibrational methods continue to occur, and several sessions of the conference were devoted to discussion of these advances and the associated new directions in TRVS. Continuing the interdisciplinary tradition of the TRVS meetings, applications of time-resolved vibrational methods to problems in physics, biology, materials science, and chemistry comprised a large portion of the papers presented at the conference.

Dyer, R.B.; Martinez, M.A.D.; Shreve, A.; Woodruff, W.H. [comps.

1997-04-01T23:59:59.000Z

385

Characterization of the Electronic and Chemical Structure at the Thin Film Solar Cell Interfaces: June 2005 -- June 2009  

SciTech Connect (OSTI)

Study using photoelectron spectroscopy, inverse photoemission, and X-ray absorption and emission to derive the electronic structure of interfaces in CIGSS and CdTe thin-film solar cells.

Heske, C.

2009-09-01T23:59:59.000Z

386

UV-Raman spectroscopy, X-ray photoelectron spectroscopy, and temperature programmed desorption studies of model and bulk heterogeneous catalysts  

SciTech Connect (OSTI)

X-ray photoelectron spectroscopy (XPS) and Temperature Programmed Desorption (TPD) have been used to investigate the surface structure of model heterogeneous catalysts in ultra-high vacuum (UHV). UV-Raman spectroscopy has been used to probe the structure of bulk model catalysts in ambient and reaction conditions. The structural information obtained through UV-Raman spectroscopy has been correlated with both the UHV surface analysis and reaction results. The present day propylene and ethylene polymerization catalysts (Ziegler-Natta catalysts) are prepared by deposition of TiCl{sub 4} and a Al(Et){sub 3} co-catalyst on a microporous Mg-ethoxide support that is prepared from MgCl{sub 2} and ethanol. A model thin film catalyst is prepared by depositing metallic Mg on a Au foil in a UHV chamber in a background of TiCl{sub 4} in the gas phase. XPS results indicate that the Mg is completely oxidized to MgCl{sub 2} by TiCl{sub 4} resulting in a thin film of MgCl{sub 2}/TiCl{sub x}, where x = 2, 3, and 4. To prepare an active catalyst, the thin film of MgCl{sub 2}/TiCl{sub x} on Au foil is enclosed in a high pressure cell contained within the UHV chamber and exposed to {approx}1 Torr of Al(Et){sub 3}.

Tewell, Craig R.

2002-08-19T23:59:59.000Z

387

Volume 55, Number 2, 2001 APPLIED SPECTROSCOPY 1110003-7028 / 01 / 5502-0111$2.00 / 0 q 2001 Society for Applied Spectroscopy  

E-Print Network [OSTI]

Society for Applied Spectroscopy accelerated paper Negligible Sample Heating from Synchrotron Infrared; DPPC; Beam; Heating. INTRODUCTION Infrared (IR) spectroscopy is one of the most sensitive analytical.H.C.) The use of synchrotron sources for infrared (IR) spectromicroscopy provides greatly increased brightness

388

Electronic structure and f-orbital occupancy in Yb-substituted CeCoIn5  

SciTech Connect (OSTI)

The local structure and 4f orbital occupancy have been investigated in Ce{sub 1?x}Yb{sub x}CoIn{sub 5} via Yb L{sub III}-edge extended x-ray absorption fine structure (EXAFS), Ce and Yb L{sub III}-edge x-ray absorption near-edge structure (XANES), and angle-resolved photoemission spectroscopy (ARPES) measurements. Yb(III) (4f{sup 13}) is the hole analog of Ce(III) (4f{sup 1}). Yb is found to be strongly intermediate-valent in Ce{sub 1?x}Yb{sub x}CoIn{sub 5} throughout the entire doping range, including pure YbCoIn{sub 5}, with an f-hole occupancy for Yb of n{sub f} ? 0.3 (i.e. Yb{sup 2.3+}), independent of Yb concentration and independent of temperature down to T = 20 K. In contrast, the f-electron orbital occupancy for Ce remains close to 1 for all Yb concentrations, suggesting that there is no mutual influence on n{sub f} between neighboring Ce and Yb sites. Likewise, ARPES measurements at 12 K have found that the electronic structure along {Gamma} ? X is not sensitive to the Yb substitution, suggesting that the Kondo hybridization of Ce f electrons with the conduction band is not affected by the presence of Yb impurities in the lattice. The emerging picture is that in Ce{sub 1?x}Yb{sub x}CoIn{sub 5} there are two networks, interlaced but independent, that couple to the conduction band: one network of Ce ions in the heavy-fermion limit, one network of Yb ions in the strongly intermediate-valent limit. The robustness of the local and electronic structure to doping suggests the absence of charge transfer between the Ce and Yb ions, and may explain the relative robustness of superconductivity for this Ce-site substitution as compared to the In-site substitution.

Booth, C. H.; Durakiewicz, T.; Capan, C.; Hurt, D.; Bianchi, A. D.; Joyce, J.J.; Fisk, Z.

2011-05-03T23:59:59.000Z

389

Optical re-injection in cavity-enhanced absorption spectroscopy  

SciTech Connect (OSTI)

Non-mode-matched cavity-enhanced absorption spectrometry (e.g., cavity ringdown spectroscopy and integrated cavity output spectroscopy) is commonly used for the ultrasensitive detection of trace gases. These techniques are attractive for their simplicity and robustness, but their performance may be limited by the reflection of light from the front mirror and the resulting low optical transmission. Although this low transmitted power can sometimes be overcome with higher power lasers and lower noise detectors (e.g., in the near-infrared), many regimes exist where the available light intensity or photodetector sensitivity limits instrument performance (e.g., in the mid-infrared). In this article, we describe a method of repeatedly re-injecting light reflected off the front mirror of the optical cavity to boost the cavity's circulating power and deliver more light to the photodetector and thus increase the signal-to-noise ratio of the absorption measurement. We model and experimentally demonstrate the method's performance using off-axis cavity ringdown spectroscopy (OA-CRDS) with a broadly tunable external cavity quantum cascade laser. The power coupled through the cavity to the detector is increased by a factor of 22.5. The cavity loss is measured with a precision of 2 × 10{sup ?10} cm{sup ?1}/?(Hz;) an increase of 12 times over the standard off-axis configuration without reinjection and comparable to the best reported sensitivities in the mid-infrared. Finally, the re-injected CRDS system is used to measure the spectrum of several volatile organic compounds, demonstrating the improved ability to resolve weakly absorbing spectroscopic features.

Leen, J. Brian, E-mail: b.leen@lgrinc.com; O’Keefe, Anthony [Los Gatos Research, 67 E. Evelyn Avenue, Suite 3, Mountain View, California 94041 (United States)

2014-09-15T23:59:59.000Z

390

Spatial confinement effects in laser-induced breakdown spectroscopy  

SciTech Connect (OSTI)

The spatial confinement effects in laser-induced breakdown of aluminum (Al) targets in air have been investigated both by optical emission spectroscopy and fast photography. A KrF excimer laser was used to produce plasmas from Al targets in air. Al atomic emission lines show an obvious enhancement in the emission intensity when a pair of Al-plate walls were placed to spatially confine the plasma plumes. Images of the Al plasma plumes showed that the plasma plumes evolved into a torus shape and were compressed in the Al walls. The mechanism for the confinement effects was discussed using shock wave theory.

Shen, X. K.; Sun, J.; Ling, H.; Lu, Y. F. [Department of Electrical Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588-0511 (United States)

2007-08-20T23:59:59.000Z

391

Dynamic force spectroscopy on multiple bonds: experiments and model  

E-Print Network [OSTI]

We probe the dynamic strength of multiple biotin-streptavidin adhesion bonds under linear loading using the biomembrane force probe setup for dynamic force spectroscopy. Measured rupture force histograms are compared to results from a master equation model for the stochastic dynamics of bond rupture under load. This allows us to extract the distribution of the number of initially closed bonds. We also extract the molecular parameters of the adhesion bonds, in good agreement with earlier results from single bond experiments. Our analysis shows that the peaks in the measured histograms are not simple multiples of the single bond values, but follow from a superposition procedure which generates different peak positions.

T. Erdmann; S. Pierrat; P. Nassoy; U. S. Schwarz

2007-12-18T23:59:59.000Z

392

Probing the membrane potential of living cells by dielectric spectroscopy  

E-Print Network [OSTI]

In this paper we demonstrate a quantitative way to measure the membrane potential of live cells by dielectric spectroscopy. We also show that the values of the membrane potential obtained using our technique are in good agreement with those obtained using traditional methods-voltage sensitive dyes. The membrane potential is determined by fitting the experimental dielectric dispersion curves with the dispersion curves obtain from a theoretical model. Variations in the membrane potential were induced by modifying the concentration of potassium chloride in the solution of the cell suspension in the presence of valinomycin. For exemplification of the method, E. coli were chosen for our experiments.

Corina Bot; Camelia Prodan

2008-12-17T23:59:59.000Z

393

Band Structure Asymmetry of Bilayer Graphene Revealed by Infrared Spectroscopy  

SciTech Connect (OSTI)

We report on infrared spectroscopy of bilayer graphene integrated in gated structures. We observe a significant asymmetry in the optical conductivity upon electrostatic doping of electrons and holes. We show that this finding arises from a marked asymmetry between the valence and conduction bands, which is mainly due to the inequivalence of the two sublattices within the graphene layer and the next-nearest-neighbor interlayer coupling. From the conductivity data, the energy difference of the two sublattices and the interlayer coupling energy are directly determined.

Li, Z.Q.; Henriksen, E.A.; Jiang, Z.; Hao, Zhao; Martin, Michael C.; Kim, P.; Stormer, H.L.; Basov, Dimitri N.

2008-12-10T23:59:59.000Z

394

Sensitivity Increases for the TITAN Decay Spectroscopy Program  

E-Print Network [OSTI]

The TITAN facility at TRIUMF has recently initiated a program of performing decay spectroscopy measurements in an electron-beam ion-trap (EBIT). The unique environment of the EBIT provides backing-free storage of the radioactive ions, while guiding charged decay particles from the trap centre via the strong magnetic field. This measurement technique is able to provide a significant increase in detection sensitivity for photons which result from radioactive decay. A brief overview of this device is presented, along with methods of improving the signal-to-background ratio for photon detection by reducing Compton scattered events, and eliminating vibrational noise.

K. G. Leach; A. Lennarz; A. Grossheim; C. Andreoiu; J. Dilling; D. Frekers; M. Good; S. Seeraji

2014-10-30T23:59:59.000Z

395

Quantum Process Tomography by 2D Fluorescence Spectroscopy  

E-Print Network [OSTI]

Reconstruction of the dynamics (quantum process tomography) of the single-exciton manifold in energy transfer systems is proposed here on the basis of two-dimensional fluorescence spectroscopy (2D-FS) with phase-modulation. The quantum-process-tomography protocol introduced here benefits from, e.g., the sensitivity enhancement and signal-to-noise ratio ascribed to 2D-FS. Although the isotropically averaged spectroscopic signals depend on the quantum yield parameter $\\Gamma$ of the doubly-excited-exciton manifold, it is shown that the reconstruction of the dynamics is insensitive to this parameter. Applications to foundational and applied problems, as well as further extensions, are discussed.

Leonardo A. Pachon; Andrew H. Marcus; Alan Aspuru-Guzik

2015-02-09T23:59:59.000Z

396

Quantum Process Tomography by 2D Fluorescence Spectroscopy  

E-Print Network [OSTI]

Reconstruction of the dynamics (quantum process tomography) of the single-exciton manifold in energy transfer systems is proposed here on the basis of two-dimensional fluorescence spectroscopy (2D-FS) with phase-modulation. The quantum-process-tomography protocol introduced here benefits from, e.g., the sensitivity enhancement and signal-to-noise ratio ascribed to 2D-FS. Although the isotropically averaged spectroscopic signals depend on the quantum yield parameter $\\Gamma$ of the doubly-excited-exciton manifold, it is shown that the reconstruction of the dynamics is insensitive to this parameter. Applications to foundational and applied problems, as well as further extensions, are discussed.

Pachon, Leonardo A; Aspuru-Guzik, Alan

2015-01-01T23:59:59.000Z

397

Molecular shock response of explosives: electronic absorption spectroscopy  

SciTech Connect (OSTI)

Electronic absorption spectroscopy in the range 400-800 nm was coupled to ultrafast laser generated shocks to begin addressing the question of the extent to which electronic excitations are involved in shock induced reactions. Data are presented on shocked polymethylmethacrylate (PMMA) thin films and single crystal pentaerythritol tetranitrate (PETN). Shocked PMMA exhibited thin film interference effects from the shock front. Shocked PETN exhibited interference from the shock front as well as broadband increased absorption. Relation to shock initiation hypotheses and the need for time dependent absorption data (future experiments) is briefly discussed.

Mcgrne, Shawn D [Los Alamos National Laboratory; Moore, David S [Los Alamos National Laboratory; Whitley, Von H [Los Alamos National Laboratory; Bolme, Cindy A [Los Alamos National Laboratory; Eakins, Daniel E [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

398

Excited-Nucleon Spectroscopy with 2+1 Fermion Flavors  

SciTech Connect (OSTI)

We present progress made by the Hadron Spectrum Collaboration (HSC) in determining the tower of excited nucleon states using 2+1-flavor anisotropic clover lattices. The HSC has been investigating interpolating operators projected into irreducible representations of the cubic group in order to better calculate two-point correlators for nucleon spectroscopy; results are published for quenched and 2-flavor anisotropic Wilson lattices. In this work, we present the latest results using a new technique, distillation, which allows us to reach higher statistics than before. Future directions will be outlined at the end.

Cohen, Saul; Foley, Justin; Morningstar, Colin; Wong, Ricky; Edwards, Robert G; Joo, Balint; Richards, David G; Juge, Jimmy; Lin, Huey-Lin; Mathur, Nilmani; Peardon, Micheal J

2010-01-01T23:59:59.000Z

399

Photoelectron spectroscopy of boron aluminum hydride cluster anions  

SciTech Connect (OSTI)

Boron aluminum hydride clusters are studied through a synergetic combination of anion photoelectron spectroscopy and density functional theory based calculations. Boron aluminum hydride cluster anions, B{sub x}Al{sub y}H{sub z}{sup ?}, were generated in a pulsed arc cluster ionization source and identified by time-of-flight mass spectrometry. After mass selection, their photoelectron spectra were measured by a magnetic bottle-type electron energy analyzer. The resultant photoelectron spectra as well as calculations on a selected series of stoichiometries reveal significant geometrical changes upon substitution of aluminum atoms by boron atoms.

Wang, Haopeng; Zhang, Xinxing; Ko, Yeon Jae; Gantefoer, Gerd; Bowen, Kit H., E-mail: kbowen@jhu.edu, E-mail: kiran@mcneese.edu [Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Li, Xiang [Center for Space Science and Technology, University of Maryland–Baltimore County, Baltimore, Maryland 21250 (United States)] [Center for Space Science and Technology, University of Maryland–Baltimore County, Baltimore, Maryland 21250 (United States); Kiran, Boggavarapu, E-mail: kbowen@jhu.edu, E-mail: kiran@mcneese.edu [Department of Chemistry and Physics, McNeese State University, Lake Charles, Louisiana 70609 (United States)] [Department of Chemistry and Physics, McNeese State University, Lake Charles, Louisiana 70609 (United States); Kandalam, Anil K. [Department of Physics, West Chester University, West Chester, Pennsylvania 19383 (United States)] [Department of Physics, West Chester University, West Chester, Pennsylvania 19383 (United States)

2014-04-28T23:59:59.000Z

400

Vibrationally Resolved Photoelectron Spectroscopy of Di-Gold Carbonyl  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched Ferromagnetism inS-4500IIVasudha PatriPhotoelectron Spectroscopy of Cold C60-Clusters

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they are not comprehensive nor are they the most current set.
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to obtain the most current and comprehensive results.


401

Vibrationally-resolved Photoelectron Spectroscopy of the Model GFP  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched Ferromagnetism inS-4500IIVasudha PatriPhotoelectron Spectroscopy of Cold

402

PHOTOMETRICALLY TRIGGERED KECK SPECTROSCOPY OF FERMI BL LACERTAE OBJECTS  

SciTech Connect (OSTI)

We report on Keck spectra of 10 Fermi blazars. J0622+3326, previously unobserved, is shown to be a flat-spectrum radio quasar at redshift z = 1.062. The others are known BL Lac type objects that have resisted previous attempts to secure redshifts. Using a photometric monitoring campaign with the 0.76 m Katzman Automatic Imaging Telescope at Lick Observatory, we identified epochs when the relativistic jet emission was fainter than usual, thus triggering the Keck spectroscopy. This strategy gives improved sensitivity to stars and ionized gas in the host galaxy, thereby providing improved redshift constraints for seven of these sources.

Shaw, Michael S.; Romani, Roger W. [Department of Physics/KIPAC, Stanford University, Stanford, CA 94305 (United States); Filippenko, Alexei V.; Cenko, S. Bradley; Li, Weidong [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States)

2013-11-01T23:59:59.000Z

403

Spectroscopy and Topological Phases for Organic Excitons | MIT-Harvard  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassiveSubmittedStatus Tom Fletcher,Future |CarlosSpeakersSpectroscopy Print InCenter

404

Multi-object spectroscopy of low redshift EIS clusters. II  

E-Print Network [OSTI]

We present the results of carrying out multi-object spectroscopy in 10 EIS cluster fields. Based on the list of 345 galaxy redshifts we identify significant 3D-density enhancements. For 9 of the EIS clusters we identify significant 3D-concentrations corresponding to the originally detected cluster candidate. We find redshifts in the range 0.097<=z<=0.257 which is in good agreement with the matched filter estimate of z_MF=0.2. We estimate velocity dispersions in the range 219-1160 km/s for the confirmed clusters.

L. F. Olsen; L. Hansen; H. E. Joergensen; C. Benoist; L. da Costa; M. Scodeggio

2003-08-01T23:59:59.000Z

405

E-Print Network 3.0 - atr-ftir spectroscopy study Sample Search...  

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

Technologies and Information Sciences 2 Using Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy to Investigate the Surface Chemistry of a Drying Summary:...

406

E-Print Network 3.0 - atr ftir spectroscopy Sample Search Results  

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

Biology and Medicine ; Materials Science 3 Using Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy to Investigate the Surface Chemistry of a Drying Summary:...

407

E-Print Network 3.0 - atr-ftir spectroscopy detects Sample Search...  

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

microscopy and lateral... by polarized attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. The bilayers... and lipid- protein interactions in...

408

Scanning angle Raman spectroscopy: Investigation of Raman scatter enhancement techniques for chemical analysis  

SciTech Connect (OSTI)

This thesis outlines advancements in Raman scatter enhancement techniques by applying evanescent fields, standing-waves (waveguides) and surface enhancements to increase the generated mean square electric field, which is directly related to the intensity of Raman scattering. These techniques are accomplished by employing scanning angle Raman spectroscopy and surface enhanced Raman spectroscopy. A 1064 nm multichannel Raman spectrometer is discussed for chemical analysis of lignin. Extending dispersive multichannel Raman spectroscopy to 1064 nm reduces the fluorescence interference that can mask the weaker Raman scattering. Overall, these techniques help address the major obstacles in Raman spectroscopy for chemical analysis, which include the inherently weak Raman cross section and susceptibility to fluorescence interference.

Meyer, Matthew W. [Ames Laboratory

2013-03-14T23:59:59.000Z

409

Human Cardiac High-Energy Phosphate Metabolite Concentrationsby ID-Resolved NMR Spectroscopy  

E-Print Network [OSTI]

Human Cardiac High-Energy Phosphate Metabolite Concentrationsby ID-Resolved NMR Spectroscopy Paul A myocytes can contribute no metabolite signal to the observed spectrum, the hypoth- esis

Atalar, Ergin

410

Photoelectron Spectroscopy and Theoretical Study of M(IO3)2&ndash...  

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

be explained by the hyperhalogen behavior of their neutral counterparts. Citation: Hou GL, MM Wu, H Wen, QN Sun, XB Wang, and W Zheng.2013."Photoelectron Spectroscopy and...

411

E-Print Network 3.0 - absorption spectroscopies progress Sample...  

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

nanoantenna arrays Summary: absorption (SEIRA) spectroscopy (7-14). Until recently, the bulk of SEIRA studies have revolved around... collectively en- hanced IR absorption...

412

Identification of excitonic phonon sideband by photoluminescence spectroscopy of single-walled carbon-13 nanotubes  

E-Print Network [OSTI]

1 Identification of excitonic phonon sideband by photoluminescence spectroscopy of single of the most promising approaches for the determination of the structure distribution in a bulk SWNT sample

Maruyama, Shigeo

413

Chemical Modification of Porous Alumina for Nanowire Templating and NEXAFS Spectroscopy of Aqueous ATP  

E-Print Network [OSTI]

Two: NEXAFS Spectroscopy of Aqueous ATP Chapter 3: AdenosineAdenosine triphsophate (ATP) is an important biomoleculeThe ubiquitous presence of ATP in organisms implies that

Kelly, Daniel Nicholas

2010-01-01T23:59:59.000Z

414

E-Print Network 3.0 - absorption line spectroscopy Sample Search...  

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

University Collection: Physics 88 Terahertz Time-Domain Spectroscopy Study of Silica Aerogels and Adsorbed Molecular Jiangquan Zhang and D. Grischkowsky* Summary: absorption...

415

E-Print Network 3.0 - absorption spectroscopy aas Sample Search...  

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

Sciences and Ecology 18 Terahertz Time-Domain Spectroscopy Study of Silica Aerogels and Adsorbed Molecular Jiangquan Zhang and D. Grischkowsky* Summary: absorption...

416

E-Print Network 3.0 - absorption spectroscopy method Sample Search...  

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

Collection: Mathematics 83 Terahertz Time-Domain Spectroscopy Study of Silica Aerogels and Adsorbed Molecular Jiangquan Zhang and D. Grischkowsky* Summary: , but different...

417

E-Print Network 3.0 - absorption spectroscopy investigation Sample...  

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

Collection: Mathematics 79 Terahertz Time-Domain Spectroscopy Study of Silica Aerogels and Adsorbed Molecular Jiangquan Zhang and D. Grischkowsky* Summary: absorption...

418

E-Print Network 3.0 - absorption spectroscopy distance Sample...  

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

> >> Page: << < 1 2 3 4 5 > >> 41 Terahertz Time-Domain Spectroscopy Study of Silica Aerogels and Adsorbed Molecular Jiangquan Zhang and D. Grischkowsky* Summary: absorption...

419

E-Print Network 3.0 - absorption spectroscopy principles Sample...  

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

gas analysis Alexander Fateev, Snnik Clausen Summary: applications and in particular in atomicmolecular absorption spectroscopy, the transition moment is replaced... +CO+CO2)....

420

E-Print Network 3.0 - atomic absorption spectroscopy Sample Search...  

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

Search Powered by Explorit Topic List Advanced Search Sample search results for: atomic absorption spectroscopy Page: << < 1 2 3 4 5 > >> 1 Xray Absorption Near Edge...

Note: This page contains sample records for the topic "angle-resolved photoemission spectroscopy" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

E-Print Network 3.0 - absorption spectroscopy establishes Sample...  

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

gas analysis Alexander Fateev, Snnik Clausen Summary: applications and in particular in atomicmolecular absorption spectroscopy, the transition moment is replaced... +CO+CO2)....

422

E-Print Network 3.0 - ac impedance spectroscopy Sample Search...  

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

and Electrochemical Impedance for Protein Sensing Using Two-Tone Excitation Summary: . In electrochemical impedance spectroscopy (EIS), the magnitude and phase of the...

423

E-Print Network 3.0 - active mhd spectroscopy Sample Search Results  

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

MHD spectroscopy); fast particle... The Workshop will concentrate on burning plasma research in the areas of Plasma Transport and Confinement, MHD... for experimentalists and...

424

E-Print Network 3.0 - absorption infrared spectroscopy Sample...  

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

electron paramagnetic resonance spectroscopy to establish the technology needed... , terahertz radiation is between microwave and infrared. the dynamics of many important ......

425

E-Print Network 3.0 - assisted synthesis spectroscopy Sample...  

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

search results for: assisted synthesis spectroscopy Page: << < 1 2 3 4 5 > >> 1 Chemistry and Chemical Biology Summary: .rpi.edudeptchemchemfacultyprofileswentland.html...

426

E-Print Network 3.0 - absorption gamma-ray spectroscopy Sample...  

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

by Explorit Topic List Advanced Search Sample search results for: absorption gamma-ray spectroscopy Page: << < 1 2 3 4 5 > >> 1 1090 IEEE TRANSACTIONS ON NUCLEAR SCIENCE,...

427

Supercritical fluid chromatography/supersonic jet spectroscopy. Progress report, November 1, 1983-January 31, 1984. [Supersonic jet spectroscopy  

SciTech Connect (OSTI)

Modifications were made in the designs for the supercritical fluid extraction/fractionation unit and the vacuum chamber for supersonic jet spectroscopy. The construction of the extraction/fractionation unit is nearly complete and the construction of the vaccum system is presently underway. An interface has been constructed for supercritical fluid chromatography - mass spectrometry based on direct fluid injection with provision for circulating a heated liquid for precise temperature control. Initial experiments indicate effective transfer of the chromatographic effluent, and preservation of chromatographic efficiency. 1 reference, 4 figures.

Lee, M.L.; Goates, S.R.

1984-01-01T23:59:59.000Z

428

Soft-x-ray spectroscopy study of nanoscale materials  

SciTech Connect (OSTI)

The ability to control the particle size and morphology of nanoparticles is of crucial importance nowadays both from a fundamental and industrial point of view considering the tremendous amount of high-tech applications. Controlling the crystallographic structure and the arrangement of atoms along the surface of nanostructured material will determine most of its physical properties. In general, electronic structure ultimately determines the properties of matter. Soft X-ray spectroscopy has some basic features that are important to consider. X-ray is originating from an electronic transition between a localized core state and a valence state. As a core state is involved, elemental selectivity is obtained because the core levels of different elements are well separated in energy, meaning that the involvement of the inner level makes this probe localized to one specific atomic site around which the electronic structure is reflected as a partial density-of-states contribution. The participation of valence electrons gives the method chemical state sensitivity and further, the dipole nature of the transitions gives particular symmetry information. The new generation synchrotron radiation sources producing intensive tunable monochromatized soft X-ray beams have opened up new possibilities for soft X-ray spectroscopy. The introduction of selectively excited soft X-ray emission has opened a new field of study by disclosing many new possibilities of soft X-ray resonant inelastic scattering. In this paper, some recent findings regarding soft X-ray absorption and emission studies of various nanostructured systems are presented.

Guo, J.-H.

2005-07-30T23:59:59.000Z

429

The TITAN in-trap decay spectroscopy facility at TRIUMF  

E-Print Network [OSTI]

This article presents an upgraded in-trap decay spectroscopy apparatus which has been developed and constructed for use with TRIUMF's Ion Trap for Atomic and Nuclear science (TITAN). This device consists of an open-access electron-beam ion-trap (EBIT), which is surrounded radially by seven low-energy planar Si(Li) detectors. The environment of the EBIT allows for the detection of low-energy photons by providing backing-free storage of the radioactive ions, while guiding charged decay particles away from the trap centre via the strong (up to 6 T) magnetic field. In addition to excellent ion confinement and storage, the EBIT also provides a venue for performing decay spectroscopy on highly-charged radioactive ions. Recent technical advancements have been able to provide a significant increase in sensitivity for low-energy photon detection, towards the goal of measuring weak electron-capture branching ratios of the intermediate nuclei in the two-neutrino double beta ($2\

K. G. Leach; A. Grossheim; A. Lennarz; T. Brunner; J. R. Crespo López-Urrutia; A. T. Gallant; M. Good; R. Klawitter; A. A. Kwiatkowski; T. Ma; T. D. Macdonald; S. Seeraji; M. C. Simon; C. Andreoiu; J. Dilling; D. Frekers

2014-11-22T23:59:59.000Z

430

Terahertz spectroscopy of two-dimensional subwavelength plasmonic structures  

SciTech Connect (OSTI)

The fascinating properties of plasmonic structures have had significant impact on the development of next generation ultracompact photonic and optoelectronic components. We study two-dimensional plasmonic structures functioning at terahertz frequencies. Resonant terahertz response due to surface plasmons and dipole localized surface plasmons were investigated by the state-of-the-art terahertz time domain spectroscopy (THz-TDS) using both transmission and reflection configurations. Extraordinary terahertz transmission was demonstrated through the subwavelength metallic hole arrays made from good conducting metals as well as poor metals. Metallic arrays m!lde from Pb, generally a poor metal, and having optically thin thicknesses less than one-third of a skin depth also contributed in enhanced THz transmission. A direct transition of a surface plasmon resonance from a photonic crystal minimum was observed in a photo-doped semiconductor array. Electrical controls of the surface plasmon resonances by hybridization of the Schottkey diode between the metallic grating and the semiconductor substrate are investigated as a function of the applied reverse bias. In addition, we have demonstrated photo-induced creation and annihilation of surface plasmons with appropriate semiconductors at room temperature. According to the Fano model, the transmission properties are characterized by two essential contributions: resonant excitation of surface plasmons and nonresonant direct transmission. Such plasmonic structures may find fascinating applications in terahertz imaging, biomedical sensing, subwavelength terahertz spectroscopy, tunable filters, and integrated terahertz devices.

Azad, Abul K [Los Alamos National Laboratory; Chen, Houtong [Los Alamos National Laboratory; Taylor, Antoinette [Los Alamos National Laboratory; O' Hara, John F [Los Alamos National Laboratory; Han, Jiaguang [OSU; Lu, Xinchao [OSU; Zhang, Weili [OSU

2009-01-01T23:59:59.000Z

431

Near Infrared Spectroscopy for Burning Plasma Diagnostic Applications  

SciTech Connect (OSTI)

Ultraviolet and visible (UV-VIS, 200-750 nm) atomic spectroscopy of neutral and ion fuel species (H, D, T, Li) and impurities (e.g. He, Be, C, W) is a key element of plasma control and diagnosis on ITER and future magnetically confined burning plasma experiments (BPX). Spectroscopic diagnostic implementation and performance issues that arise in the BPX harsh nuclear environment in the UV-VIS range, e.g., degradation of first mirror reflectivity under charge-exchange atom bombardment (erosion) and impurity deposition, permanent and dynamic loss of window and optical fiber transmission under intense neutron and {gamma}-ray fluxes, are either absent or not as severe in the near-infrared (NIR, 750-2000 nm) range. An initial survey of NIR diagnostic applications has been undertaken on the National Spherical Torus Experiment. It is demonstrated that NIR spectroscopy can address machine protection and plasma control diagnostic tasks, as well as plasma performance evaluation and physics studies. Emission intensity estimates demonstrate that NIR measurements are possible in the BPX plasma operating parameter range. Complications in the NIR range due to parasitic background emissions are expected to occur at very high plasma densities, low impurity densities, and at high plasma facing component temperatures.

Soukhanovskii, V A

2008-06-18T23:59:59.000Z

432

Unconventional Electronic Reconstruction in Undoped (Ba,Sr)Fe2As2 Across the Spin Density Wave Transition  

SciTech Connect (OSTI)

Through a systematic high-resolution angle-resolved photoemission study of the iron pnictide compounds (Ba,Sr)Fe{sub 2}As{sub 2}, we show that the electronic structures of these compounds are significantly reconstructed across the spin density wave transition, which cannot be described by a simple folding scenario of conventional density wave ordering. Moreover, we find that LDA calculations with an incorporated suppressed magnetic moment of 0.5{mu}{sub B} can match well the details in the reconstructed electronic structure, suggesting that the nature of magnetism in the pnictides is more itinerant than local, while the origin of suppressed magnetic moment remains an important issue for future investigations.

Yi, M.

2010-06-02T23:59:59.000Z

433

Evidence against a charge density wave on Bi(111)  

SciTech Connect (OSTI)

The Bi(111) surface was studied by scanning tunneling microscopy (STM), transmission electron microscopy (TEM) and angle-resolved photoemission (ARPES) in order to verify the existence of a recently proposed surface charge density wave (CDW) [Ch. R. Ast and H. Hoechst Phys. Rev. Lett. 90, 016403 (2003)]. The STM and TEM results to not support a CDW scenario at low temperatures. Furthermore, the quasiparticle interference pattern observed in STM confirms the spin-orbit split character of the surface states which prevents the formation of a CDW, even in the case of good nesting. The dispersion of the electronic states observed with ARPES agrees well with earlier findings. In particular, the Fermi contour of the electron pocket at the centre of the surface Brillouin zone is found to have a hexagonal shape. However, no gap opening or other signatures of a CDW phase transition can be found in the temperature-dependent data.

Kim, T.K.; Wells, J.; Kirkegaard, C.; Li, Z.; Hoffmann, S.V.; Gayone, J.E.; Fernancez-Torrente, I.; Haberle, P.; Pascual, J.I.; Moore,K.T.; Schwartz, A.J.; He, H.; Spence, J.C.H.; Downing, K.H.; Lazar, S.; Tichelaar, F.D.; Borisenko, S.V.; Knupfer, M.; Hofmann, Ph.

2005-05-01T23:59:59.000Z

434

Evidence against a charge density wave on Bi(111)  

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

The Bi(111) surface was studied by scanning tunneling microscopy (STM), transmission electron microscopy (TEM) and angle-resolved photoemission (ARPES) in order to verify the existence of a recently proposed surface charge density wave (CDW) [Ch. R. Ast and H. H¨ochst Phys. Rev. Lett. 90, 016403 (2003)]. The STM and TEM results to not support a CDW scenario at low temperatures. Furthermore, the quasiparticle interference pattern observed in STM confirms the spin-orbit split character of the surface states which prevents the formation of a CDW, even in the case of good nesting. The dispersion of the electronic states observed with ARPES agrees well with earlier findings. In particular, the Fermi contour of the electron pocket at the centre of the surface Brillouin zone is found to have a hexagonal shape. However, no gap opening or other signatures of a CDW phase transition can be found in the temperature-dependent data.

Kim, T.; Wells, J.; Kirkegaard, C.; Li, Z.; Hoffmann, S.; Gayone, J.; Fernandez-Torrente, I.; Haberle, P.; Pascual, J.; Moore, K.; Schwartz, A.; He, H.; Spence, J.; Downing, K.; Lazar, S.; Tichelaar, F.; Borisenko, S.; Knupfer, M.; Hofmann, Ph.

2005-08-01T23:59:59.000Z

435

Effects of charge inhomogeneities on elementary excitations in La2-xSrxCuO?  

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

Purely local experimental probes of many copper oxide superconductors show that their electronic states are inhomogeneous in real space. For example, scanning tunneling spectroscopic imaging shows strong variations in real space, and according to nuclear quadrupole resonance (NQR) studies, the charge distribution in the bulk varies on the nanoscale. However, the analysis of the experimental results utilizing spatially averaged probes often ignores this fact. We have performed a detailed investigation of the doping dependence of the energy and linewidth of the zone-boundary Cu-O bond-stretching vibration in La2-xSrxCuO? by inelastic neutron scattering. Both our results as well as previously reported angle-dependent momentum widths of the electronic spectral function detected by angle-resolved photoemission can be reproduced by including the same distribution of local environments extracted from the NQR analysis.

Park, S. R.; Hamann, A.; Pintschovius, L.; Lamago, D.; Khaliullin, G.; Fujita, M.; Yamada, K.; Gu, G. D.; Tranquada, J. M.; Reznik, D.

2011-12-01T23:59:59.000Z

436

Improving metastable impact electron spectroscopy and ultraviolet photoelectron spectroscopy signals by means of a modified time-of-flight separation  

SciTech Connect (OSTI)

The separation of ultraviolet photoelectron spectroscopy (UPS) and metastable impact electron spectroscopy (MIES) is usually performed by a time-of-flight (ToF) separation using pre-set ToF for both types of signal. In this work, we present a new, improved ex situ signal separation method for the separation of MIES and UPS for every single measurement. Signal separation issues due to changes of system parameters can be overcome by changing the ToF separation and therefore allowing for the application of a wider range of measuring conditions. The method also enables to identify and achieve separation of the two signals without any time consuming calibration and the use of any special material for the calibration. Furthermore, changes made to the discharge source are described that enable to operate an existing MIES/UPS source over a broader range of conditions. This allows for tuning of the yield of UV photons and metastable rare gas atoms leading to an improved signal to noise ratio. First results of this improved setup are well in agreement with spectra reported in literature and show increased resolution and higher signal intensities for both MIE and UP spectra compared to the previous, non-optimized setup.

Spirkl, Florian M.; Kunz, Sebastian; Schweinberger, Florian F.; Farnbacher, Adrian N.; Schroeter, Richard; Heiz, Ulrich [Technische Universitaet Muenchen, Department Chemie, Lichtenbergstrasse 4, D-85748 Garching (Germany)

2012-01-15T23:59:59.000Z

437

A new endstation at the Swiss Light Source for ultraviolet photoelectron spectroscopy, X-ray photoelectron spectroscopy, and X-ray absorption spectroscopy measurements of liquid solutions  

SciTech Connect (OSTI)

A new liquid microjet endstation designed for ultraviolet (UPS) and X-ray (XPS) photoelectron, and partial electron yield X-ray absorption (XAS) spectroscopies at the Swiss Light Source is presented. The new endstation, which is based on a Scienta HiPP-2 R4000 electron spectrometer, is the first liquid microjet endstation capable of operating in vacuum and in ambient pressures up to the equilibrium vapor pressure of liquid water at room temperature. In addition, the Scienta HiPP-2 R4000 energy analyzer of this new endstation allows for XPS measurements up to 7000 eV electron kinetic energy that will enable electronic structure measurements of bulk solutions and buried interfaces from liquid microjet samples. The endstation is designed to operate at the soft X-ray SIM beamline and at the tender X-ray Phoenix beamline. The endstation can also be operated using a Scienta 5 K ultraviolet helium lamp for dedicated UPS measurements at the vapor-liquid interface using either He I or He II ? lines. The design concept, first results from UPS, soft X-ray XPS, and partial electron yield XAS measurements, and an outlook to the potential of this endstation are presented.

Brown, Matthew A.; Redondo, Amaia Beloqui; Duyckaerts, Nicolas; Mächler, Jean-Pierre [Institute for Chemical and Bioengineering, ETH Zürich, CH-8093 Zürich (Switzerland)] [Institute for Chemical and Bioengineering, ETH Zürich, CH-8093 Zürich (Switzerland); Jordan, Inga; Wörner, Hans Jakob [Laboratory of Physical Chemistry, ETH Zürich, CH-8093 Zürich (Switzerland)] [Laboratory of Physical Chemistry, ETH Zürich, CH-8093 Zürich (Switzerland); Lee, Ming-Tao; Ammann, Markus; Nolting, Frithjof; Kleibert, Armin; Huthwelker, Thomas; Birrer, Mario; Honegger, Juri; Wetter, Reto [Paul Scherrer Institute, CH-5232 Villigen PSI (Switzerland)] [Paul Scherrer Institute, CH-5232 Villigen PSI (Switzerland); Bokhoven, Jeroen A. van [Institute for Chemical and Bioengineering, ETH Zürich, CH-8093 Zürich (Switzerland) [Institute for Chemical and Bioengineering, ETH Zürich, CH-8093 Zürich (Switzerland); Paul Scherrer Institute, CH-5232 Villigen PSI (Switzerland)

2013-07-15T23:59:59.000Z

438

INVESTIGATIONS ON NUCLEAR SPECTROSCOPY AT THE REACTOR AND THEIR APPLICATIONS1  

E-Print Network [OSTI]

1 INVESTIGATIONS ON NUCLEAR SPECTROSCOPY AT THE REACTOR AND THEIR APPLICATIONS1 I.A. Kondurov , E. However the first work on nuclear spectroscopy was carried out before the reactor was launched; namely.M. Korotkikh, Yu.E. Loginov, V.V. Martynov Introduction Physical launch of the WWR-M reactor in the branch

Titov, Anatoly

439

Introduction Strontium Barium Niobate k-Space Spectroscopy Results Conclusions Unraveling Relaxor Phase Transitions by  

E-Print Network [OSTI]

Introduction Strontium Barium Niobate k-Space Spectroscopy Results Conclusions Unraveling Relaxor 2009 WILLIAMSBURG WORKSHOP ON FUNDAMENTAL PHYSICS OF FERROELECTRICS #12;Introduction Strontium Barium ferroelectrics Introduction Strontium Barium Niobate k-Space Spectroscopy Results Conclusions SBN ­ SrxBa1-xNb2O6

Osnabrück, Universität

440

High Precision Spectroscopy of Strontium in an Optical Lattice: Towards a New Standard for  

E-Print Network [OSTI]

High Precision Spectroscopy of Strontium in an Optical Lattice: Towards a New Standard Spectroscopy of Strontium in an Optical Lattice: Towards a New Standard for Frequency and Time Thesis directed atomic clock states equally, such that the transition frequency is unchanged. Strontium is a natural

Jin, Deborah

Note: This page contains sample records for the topic "angle-resolved photoemission spectroscopy" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Simulations of the Two-Dimensional Electronic Spectroscopy of the Photosystem II Reaction Center  

E-Print Network [OSTI]

for spectroscopic study. A purified PSII preparation capable of evolving oxygen consists of so-called BBY particlesSimulations of the Two-Dimensional Electronic Spectroscopy of the Photosystem II Reaction Center K spectroscopy of the Qy band of the D1-D2-Cyt b559 photosystem II reaction center at 77 K. We base

Mukamel, Shaul

442

RAMAN SPECTROSCOPY OF MACROSCALE FIBERS COMPRISED OF CARBON NANOTUBES OF DIFFERENT  

E-Print Network [OSTI]

RAMAN SPECTROSCOPY OF MACROSCALE FIBERS COMPRISED OF CARBON NANOTUBES OF DIFFERENT LENGTHS UNDER University Carbon nanotube (CNT) fibers are considered an excellent material for high performance engineering) Fibers Raman Spectroscopy of Macroscopic Fibers Spun from Carbon Nanotubes under Tensile Strain D

Mellor-Crummey, John

443

POLARIZATION DEPENDENT TERAHERTZ TIME-DOMAIN SPECTROSCOPY MEASUREMENTS ON ALIGNED CARBON NANOTUBE FILMS AND FIBERS  

E-Print Network [OSTI]

Dependent Terahertz Time-Domain Spectroscopy Measurements On Aligned Carbon Nanotube Films And Fibers are not well defined ! Carbon nanotube (CNT) fiber properties strongly determined by overall alignment of itsPOLARIZATION DEPENDENT TERAHERTZ TIME-DOMAIN SPECTROSCOPY MEASUREMENTS ON ALIGNED CARBON NANOTUBE

Mellor-Crummey, John

444

Saturn's tropospheric composition and clouds from Cassini/VIMS 4.65.1 lm nightside spectroscopy  

E-Print Network [OSTI]

Saturn's tropospheric composition and clouds from Cassini/VIMS 4.6­5.1 lm nightside spectroscopy and opacities) are derived from Cassini/VIMS 4.6­5.1 lm thermal emission spectroscopy on the planet's nightside and chemistry within and below Saturn's cloud decks (in the 1- to 4-bar region). Extensive testing of VIMS

445

Accepted for publicaton in The Astrophysical Journal NearInfrared Spectroscopy of Molecular  

E-Print Network [OSTI]

: reflection --- nebulae: individual (NGC 7023) #12; -- 3 -- 1. Introduction Near­infrared spectroscopic these authors apply to NGC 2023. We present near­infrared spectroscopy of H 2 emission in NGC 7023, a reflectionAccepted for publicaton in The Astrophysical Journal Near­Infrared Spectroscopy of Molecular

Martini, Paul

446

TitleA Spectroscopy Diagnostic of Plasma Gradients in ICF Imploded Cores  

E-Print Network [OSTI]

TitleA Spectroscopy Diagnostic of Plasma Gradients in ICF Imploded Cores I. Golovkin, R. Mancini, S to be a powerful diagnostic of spatially-averaged temperature and density plasma conditions at the collapse of ICF-broadened line shapes. The next step in the spectroscopy of imploded cores is the bracketing of core plasma

Louis, Sushil J.

447

Transmission electron energy-loss spectroscopy study of carbon nanotubes upon high temperature treatment  

E-Print Network [OSTI]

Transmission electron energy-loss spectroscopy study of carbon nanotubes upon high temperature electron energy-loss spectroscopy study of carbon nanotubes upon high temperature treatment B. W. Reed, M of carbon nanotube materials, grown with a pulsed-laser deposition technique but purified and heat treated

Bertsch George F.

448

Wood elastic characterization from a single sample by resonant ultrasound spectroscopy  

E-Print Network [OSTI]

Wood elastic characterization from a single sample by resonant ultrasound spectroscopy R. Longoa materials such as wood using only one sample. To do so, two complementary methods are used. First, the wood: Resonant ultrasound spectroscopy, spherical and cubic samples, wood, elastic constants 1. Introduction Wood

Paris-Sud XI, Université de

449

The effect of paramagnetic manganese cations on 1 H MR spectroscopy of the brain  

E-Print Network [OSTI]

The effect of paramagnetic manganese cations on 1 H MR spectroscopy of the brain K. S. Madsen1 has investigated the effect of Mn on 1 H MR spectroscopy using an in vivo Mn-enhanced optic tract into a stereotactic device. Images and 1 H MR spectra were acquired using a Varian 4.7T animal scanner together

450

Subcellular In Vivo 1 H MR Spectroscopy of Xenopus laevis Oocytes  

E-Print Network [OSTI]

Subcellular In Vivo 1 H MR Spectroscopy of Xenopus laevis Oocytes Seung-Cheol Lee,* Jee-Hyun Cho and Technology, Yusung-gu, Daejeon 305-701, Korea ABSTRACT In vivo magnetic resonance (MR) spectra are typically was designed to evaluate the potential of localized MR spectroscopy to investigate subcellular phenomena. Using

Hammerton, James

451

Ultrafast X-ray Absorption Spectroscopy using Laser-Driven Electron X-ray Sources (LEXS)  

E-Print Network [OSTI]

: ultrafast x-rays, x-ray absorption spectroscopy, terawatt lasers, ultrafast reaction dynamics, atomic motion atomic motion by scrutinizing the changes in x- ray absorption spectra during reactions. FirstUltrafast X-ray Absorption Spectroscopy using Laser-Driven Electron X-ray Sources (LEXS) Guangjun

Guo, Ting

452

Combined photoelectron spectroscopy and ab initio study of the hypermetallic Al3C molecule  

E-Print Network [OSTI]

Combined photoelectron spectroscopy and ab initio study of the hypermetallic Al3C molecule February 1999 The chemical structure and bonding of the hypermetallic Al3C and Al3C species have been studied by photoelectron spectroscopy and ab initio calculations. Al3C is found to have a planar

Simons, Jack

453

Spectroscopic Investigation of Al2N and Its Anion via Negative Ion Photoelectron Spectroscopy  

E-Print Network [OSTI]

Spectroscopic Investigation of Al2N and Its Anion via Negative Ion Photoelectron Spectroscopy photoelectron spectroscopy was used to elucidate the electronic and geometric structure of the gaseous Al2N/Al2N the adiabatic electron affinity of Al2N, 2.571 ( 0.008 eV, along with geometry changes upon photodetachment

Neumark, Daniel M.

454

On Impedance Spectroscopy Contribution to Failure Diagnosis in Wind Turbine Generators  

E-Print Network [OSTI]

On Impedance Spectroscopy Contribution to Failure Diagnosis in Wind Turbine Generators Mohamed Becherif1 , El Houssin El Bouchikhi2 and Mohamed Benbouzid2 Abstract ­ Wind turbines proliferation turbines. Indeed, impedance spectroscopy is already used for the diagnosis of batteries, fuel cells

Boyer, Edmond

455

ELSEVIER Journal of ElectronSpectroscopyand Related Phenomena 73 (1995) 1-11 ELECTRON SPECTROSCOPY  

E-Print Network [OSTI]

1994;in finalform 9 August 1994 Abstract The adsorption of titanium on titanium dioxide TiO2(110) has SPECTROSCOPY andRelatedPhenomena Titanium and reduced titania overlayers on titanium dioxide(110) J.T. Mayer a spectroscopy I. Introduction Titanium dioxide has received extensive attention in the surface science community

Diebold, Ulrike

456

ASSESSING THE TRIBOCORROSION BEHAVIOUR OF Cu AND Al13 BY ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY14  

E-Print Network [OSTI]

monitoring under15 open circuit conditions, i.e. electrochemical noise measurements [7]. Electrochemical16 BY ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY14 15 16 17 18 Jean Geringera , Bernard Normandb , Catherine Alemany is focused on the interests and limits of Electrochemical Impedance Spectroscopy,4 to establish

Paris-Sud XI, Université de

457

Vibrational spectra of N2: An advanced undergraduate laboratory in atomic and molecular spectroscopy  

E-Print Network [OSTI]

an advanced laboratory course focused on spectroscopy of atoms and molecules, for a diverse and solid#12;Vibrational spectra of N2: An advanced undergraduate laboratory in atomic and molecular to demonstrate molecular spectroscopy by measuring the vibrational energy spacing of nitrogen molecules

Bayram, S. Burçin

458

Proceedings of SPIE, Vol. 5825, 118-138 (2005) Ultrafast coherent spectroscopy of single semiconductor  

E-Print Network [OSTI]

ultrafast optical pulses to probe and control coherent polarizations. In this article, we review our recentProceedings of SPIE, Vol. 5825, 118-138 (2005) Ultrafast coherent spectroscopy of single work on combining ultrafast spectroscopy and near-field microscopy to probe the nonlinear optical

Peinke, Joachim

459

Infrared Spectroscopy of H3O : The 1 Fundamental Band Jian Tang and Takeshi Oka  

E-Print Network [OSTI]

Infrared Spectroscopy of H3O : The 1 Fundamental Band Jian Tang and Takeshi Oka Department, Illinois 60637 E-mail: t-oka@uchicago.edu Received December 24, 1998 The infrared spectrum of H3O 113.6(1)°. © 1999 Academic Press Key Words: infrared spectroscopy; H3O ; vibration

Oka, Takeshi

460

Infrared Charge-Modulation Spectroscopy of Defects in Phosphorus Doped Amorphous Silicon  

E-Print Network [OSTI]

Infrared Charge-Modulation Spectroscopy of Defects in Phosphorus Doped Amorphous Silicon KAI ZHU Solar, Toano, VA 23168 USA ABSTRACT We present infrared charge-modulation absorption spectra have been developing an infrared modulation spectroscopy technique that probes the optical spectra

Schiff, Eric A.

Note: This page contains sample records for the topic "angle-resolved photoemission spectroscopy" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

NONLINEAR ELASTIC WAVE NDE II. NONLINEAR WAVE MODULATION SPECTROSCOPY AND NONLINEAR TIME  

E-Print Network [OSTI]

NONLINEAR ELASTIC WAVE NDE II. NONLINEAR WAVE MODULATION SPECTROSCOPY AND NONLINEAR TIME REVERSED. This paper presents the second part of the review of Nonlinear Elastic Wave Spectroscopy (NEWS) in NDE, and describe two different methods of nonlinear NDE that provide not only damage detection but location as well

462

Science Progress (2001), 84 (1), 4568 Use of EPR spectroscopy to  

E-Print Network [OSTI]

Science Progress (2001), 84 (1), 45­68 Use of EPR spectroscopy to study macromolecular structure (EPR) spectroscopy is now part of the armory available to probe the structural aspects of proteins to a macromolecule is influenced by its microenviron- ment, analysis of the EPR spectra of site

Gopalan, Venkat

463

Optical Absorption and Photoluminescence Excitation Spectroscopy of SWNTs S. Maruyama1  

E-Print Network [OSTI]

Optical Absorption and Photoluminescence Excitation Spectroscopy of SWNTs S. Maruyama1 , Y-mail: maruyama@photon.t.u-tokyo.ac.jp Optical absorption and photoluminescence excitation (PLE) spectroscopy to the physical interest in unique excitonic features of 1-D material [3-5], clear identification of absorption

Maruyama, Shigeo

464

Absorption and photoluminescence spectroscopy on a single self-assembled charge-tunable quantum dot  

E-Print Network [OSTI]

Absorption and photoluminescence spectroscopy on a single self-assembled charge-tunable quantum dot PL and absorption spectroscopy on the same single self- assembled quantum dot in a charge the corresponding transition in absorption. We have developed a model of the Coulomb blockade to account

Ludwig-Maximilians-Universität, München

465

X-ray Absorption Spectroscopy: a powerful tool for the investigation  

E-Print Network [OSTI]

X-ray Absorption Spectroscopy: a powerful tool for the investigation of the role of metals is to illustrate the potentialities of X-ray Absorption Spectroscopy (XAS) to investigate structural properties Protein and Zinc ions 2 Introduction to the X-ray Absorption Spec- troscopy XAS uses Synchrotron Radiation

Morante, Silvia

466

Near-infrared spectroscopy measurement of the pulsatile component of cerebral blood flow and volume from  

E-Print Network [OSTI]

Near-infrared spectroscopy measurement of the pulsatile component of cerebral blood flow and volume, Massachusetts 02129 E-mail: themelis@nmr.mgh.harvard.edu Abstract. We describe a near-infrared spectroscopy NIRS-Optical Instrumentation Engineers. DOI: 10.1117/1.2710250 Keywords: cerebral blood flow; cerebral blood volume; near-infrared

467

Near-Infrared Reflectance Spectroscopy is a Rapid, Cost-Effective Predictor  

E-Print Network [OSTI]

Near-Infrared Reflectance Spectroscopy is a Rapid, Cost-Effective Predictor of Seagrass Nutrients + Business Media, Inc. 2006 Abstract Near-infrared reflectance spectroscopy was used to analyze nutrient com to the laboratory, and separated into leaf and root/rhizome fractions. They were dried, ground, and near-infrared

Marsh, Helene

468

The Accuracy of Near Infrared Spectroscopy and Imaging during Focal Changes in Cerebral Hemodynamics  

E-Print Network [OSTI]

The Accuracy of Near Infrared Spectroscopy and Imaging during Focal Changes in Cerebral January 21, 2000; published online November 7, 2000 Near infrared spectroscopy (NIRS) can detect changes arterial pulsation (1,2). Near infrared spectros- copy (NIRS) was developed to measure average tissue

469

Application of near-infrared spectroscopy for discrimination of mental A. Sassarolia  

E-Print Network [OSTI]

Application of near-infrared spectroscopy for discrimination of mental workloads A. Sassarolia , F, McLean Hospital, Belmont, MA 02478 ABSTRACT We show the potential of functional near-infrared of electroencephalography. Keywords: functional near-infrared spectroscopy, brain imaging, mental workload, human computer

Jacob, Robert J.K.

470

A Method for Quantitative Mapping of Thick Oil Spills Using Imaging Spectroscopy  

E-Print Network [OSTI]

....................................................................................................................................................14 Figures 1. Image of oil emulsion from the Deepwater Horizon oil spill in the Gulf of Mexico offA Method for Quantitative Mapping of Thick Oil Spills Using Imaging Spectroscopy By Roger N. Clark (AVIRIS) Team, 2010, A method for quantitative mapping of thick oil spills using imaging spectroscopy: U

Torgersen, Christian

471

Journal of Electron Spectroscopy and Related Phenomena 154 (2007) 6062 Investigation of vanadiumsodium silicate glasses using  

E-Print Network [OSTI]

­sodium silicate glasses using XANES spectroscopy M. Faiza,, A. Mekkia, B.S. Munb, Z. Hussainb a Surface Science. Keywords: XANES; Vanadium­sodium silicate glasses; V L2,3 edges; O K edge 1. Introduction Studies on oxide vanadium-sodium silicate glasses. X-ray absorption near edge structure (XANES) spectroscopy is a pow- erful

Mekki, Abdelkarim

472

Micro-Raman spectroscopy of refractive index microstructures in silicone-based hydrogel  

E-Print Network [OSTI]

Micro-Raman spectroscopy of refractive index microstructures in silicone-based hydrogel polymers 26, 2009 (Doc. ID 102944); published March 3, 2009 Micro-Raman spectroscopy was used to study transparent hydro- gel polymer materials through a high (or medium) nu- merical aperture (NA) objective

Novotny, Lukas

473

Carbon 41 (2003) 18271831 Optical emission spectroscopy study of the influence of  

E-Print Network [OSTI]

Carbon 41 (2003) 1827­1831 Optical emission spectroscopy study of the influence of nitrogen on carbon nanotube growth a , b b b b a a *E.G. Wang , Z.G. Guo , J. Ma , M.M. Zhou , Y.K. Pu , S. Liu , G, China Received 20 June 2002; accepted 14 April 2003 Abstract In-situ optical emission spectroscopy

Zhang, Guangyu

474

A photoemission study of Pd ultrathin films on Pt(111)  

SciTech Connect (OSTI)

The origin of surface core-level shift (SCLS) of Pd thin films on Pt(111) substrate is investigated. At sub-monolayer coverage of Pd thin films, the splitting of Pd 3d core level peaks indicate the contribution of both initial and final-state of photo-ionization processes while there is almost no change on valence band (VB) spectra. When the coverage of Pd reaches to single monolayer, the final-state relaxation effect on the Pd 3d vanishes and only the initial-state effect, a negative SCLS, is present. Also, the VB spectrum at Pd monolayer films shows a clear band narrowing, that is the origin of the negative SCLS at monolayer coverage. As the Pd coverage is increased to more than monolayer thickness, the Pd 3d peaks start to show the surface layer contribution from second and third layers, positive SCLS, and the VB spectrum shows even narrower band width, possibly due to the formation of surface states and strained effect of Pd adlayers on top of the first pseudomorphic layer.

Mun, Bongjin Simon; Lee, Choongman; Stamenkovic, Vojislav; Markovic, Nenad M.; Ross Jr., Philip N.

2005-05-11T23:59:59.000Z

475

Widespread spin polarizationeffects in photoemission from topological insulators  

E-Print Network [OSTI]

note that in addition to the SME-induced po- larization e?polarized light. In this case, the SME-induced photoelectrongiven by [34, 35] 2? k e · ˆ P SME = 2 ( k e k e × ˆ , where

Jozwiak, C.

2012-01-01T23:59:59.000Z

476

Widespread spin polarizationeffects in photoemission from topological insulators  

E-Print Network [OSTI]

Today 63, 33 (2010). M. Z. Hasan and C. L. Kane, Rev. Mod.Bansil, R. J. Cava, and M. Z. Hasan, Nat Phys 6, 855 (2010).Hor, R. J. Cava, and M. Z. Hasan, Nature (London) 452, 970 (

Jozwiak, C.

2012-01-01T23:59:59.000Z

477

UV photoemission efficiency of polycrystalline CVD diamond films  

E-Print Network [OSTI]

efficiency of a polycrystalline diamond planar reflectivequantum efficiency of polycrystalline diamond films grown onallowed the growth of polycrystalline diamond thin films on

Tremsin, A S; Siegmund, OHW

2005-01-01T23:59:59.000Z

478

Surface plasmon assisted electron acceleration in photoemission from gold nanopillars  

E-Print Network [OSTI]

high intensity, ultrafast laser pulses. Lasers that generateexcited directly by ultrafast laser pulses without requiring

Nagel, Phillip M.

2013-01-01T23:59:59.000Z

479

Near-Field Focused Photoemission from Polystyrene Microspheres Studied with  

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

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480

Nonlinear Photoemission Electron Micrographs of Plasmonic Nanoholes in Gold  

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

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481

Photoemission Electron Microscopy of a Plasmonic Silver Nanoparticle  

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

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482

Study of Copper Diffusion Through Ruthenium Thin Film by Photoemission  

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

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483

Development of positron annihilation spectroscopy for characterizing neutron irradiated tungsten  

SciTech Connect (OSTI)

Tungsten samples (6 mm diameter, 0.2 mm thick) were irradiated to 0.025 and 0.3 dpa with neutrons in the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory. Samples were then exposed to deuterium plasma in the tritium plasma experiment (TPE) at 100, 200 and 500ºC to a total fluence of 1 x 1026 m-2. Nuclear reaction analysis (NRA) and Doppler broadening positron annihilation spectroscopy (DB-PAS) were performed at various stages to characterize damage and retention. We present the first known results of neutron damaged tungsten characterized by DB-PAS in order to study defect concentration. Two positron sources, 22Na and 68Ge, probe ~58 µm and through the entire 200 µm thick samples, respectively. DB-PAS results reveal clear differences between the various irradiated samples. These results, and the calibration of DB-PAS to NRA data are presented.

C.N. Taylor; M. Shimada; D.W. Akers; M.W. Drigert; B.J. Merrill; Y. Hatano

2013-05-01T23:59:59.000Z

484

In Situ Electron Energy Loss Spectroscopy in Liquids  

E-Print Network [OSTI]

In situ scanning transmission electron microscopy (STEM) through liquids is a promising approach for exploring biological and materials processes. However, options for in situ chemical identification are limited: X-ray analysis is precluded because the holder shadows the detector, and electron energy loss spectroscopy (EELS) is degraded by multiple scattering events in thick layers. Here, we explore the limits of EELS for studying chemical reactions in their native environments in real time and on the nanometer scale. The determination of the local electron density, optical gap and thickness of the liquid layer by valence EELS is demonstrated for liquids. By comparing theoretical and experimental plasmon energies, we find that liquids appear to follow the free-electron model that has been previously established for solids. Signals at energies below the optical gap and plasmon energy of the liquid provide a high signal-to-background ratio as demonstrated for LiFePO4 in aqueous solution. The potential for using...

Holtz, Megan E; Gao, Jie; Abruña, Héctor D; Muller, David A

2012-01-01T23:59:59.000Z

485

Prompt and delayed spectroscopy of {sup 199}At  

SciTech Connect (OSTI)

The neutron-deficient nucleus {sup 199}At has been studied through {gamma}-ray and electron spectroscopy, using the recoil-decay tagging technique. Two experiments were conducted, using a gas-filled recoil separator with a focal-plane spectrometer alone and together with a germanium-detector array at the target position. The resulting level scheme for {sup 199}At includes a new isomer with a half-life of 0.80(5) {mu}s and a spin and parity of (29/2{sup +}). The 13/2{sup +} isomer, which de-excites via an M2 transition to the 9/2{sup -} ground state, was measured to have a half-life of 70(20) ns. Our earlier version of the level scheme for {sup 197}At has been updated as well.

Jakobsson, U.; Uusitalo, J.; Juutinen, S.; Leino, M.; Nieminen, P.; Greenlees, P. T.; Jones, P.; Julin, R.; Ketelhut, S.; Nyman, M.; Peura, P.; Rahkila, P.; Ruotsalainen, P.; Sandzelius, M.; Saren, J.; Scholey, C.; Sorri, J. [Department of Physics, University of Jyvaeskylae, P.O. Box 35, FI-40014 Jyvaeskylae (Finland); Andgren, K.; Cederwall, B.; Hadinia, B. [Department of Physics, Royal Institute of Technology, SE-10691 Stockholm (Sweden)

2010-10-15T23:59:59.000Z

486

Recent BaBar Results on Hadron Spectroscopy  

SciTech Connect (OSTI)

Recent results from on hadronic spectroscopy are presented, based on data collected by the BaBar experiment between 1999 and 2004. The properties of the recently discovered D*{sub sJ}(2317){sup +} and D{sub sJ}(2460){sup +} states are studied: resonance parameters and ratios of decay rates are measured from continuum e{sup +}e{sup -} production, and production rates are measured from B decays. A search for the D*{sub sJ}(2632){sup +} state whose observation has been recently reported by the SELEX Collaboration, and a search for a charged partner of the charmonium-like X(3872) state, are performed, yielding negative results. Finally, extensive searches for several pentaquark candidates, both fully inclusive and in B decays, result in no positive evidence.

Robutti, E.; /INFN, Genoa

2005-08-29T23:59:59.000Z

487

ANTIHYDROGEN PRODUCTION AND PRECISION SPECTROSCOPY WITH ATHENA/AD-1  

SciTech Connect (OSTI)

CPT invariance is a fundamental property of quantum field theories in flat space-time. Principal consequences include the predictions that particles and their antiparticles have equal masses and lifetimes, and equal and opposite electric charges and magnetic moments. It also follows that the fine structure, hyperfine structure, and Lamb shifts of matter and antimatter bound systems should be identical. It is proposed to generate new stringent tests of CPT using precision spectroscopy on antihydrogen atoms. An experiment to produce antihydrogen at rest has been approved for running at the Antiproton Decelerator (AD) at CERN. We describe the fundamental features of this experiment and the experimental approach to the first phase of the program, the formation and identification of low energy antihydrogen.

M. HOLZSCHEITER; C. AMSLER; ET AL

2000-11-01T23:59:59.000Z

488

Apparatus, system, and method for laser-induced breakdown spectroscopy  

DOE Patents [OSTI]

In laser-induced breakdown spectroscopy (LIBS), an apparatus includes a pulsed laser configured to generate a pulsed laser signal toward a sample, a constructive interference object and an optical element, each located in a path of light from the sample. The constructive interference object is configured to generate constructive interference patterns of the light. The optical element is configured to disperse the light. A LIBS system includes a first and a second optical element, and a data acquisition module. The data acquisition module is configured to determine an isotope measurement based, at least in part, on light received by an image sensor from the first and second optical elements. A method for performing LIBS includes generating a pulsed laser on a sample to generate light from a plasma, generating constructive interference patterns of the light, and dispersing the light into a plurality of wavelengths.

Effenberger, Jr., Andrew J; Scott, Jill R; McJunkin, Timothy R

2014-11-18T23:59:59.000Z

489

Reaction mechanism studies of unsaturated molecules using photofragment translational spectroscopy  

SciTech Connect (OSTI)

A number of molecules have been studied using the technique of photofragment translational spectroscopy. In Chapter One a brief introduction to the experimental technique is given. In Chapter Two the infrared multiphoton dissociation (IRMPD) of acetic acid is discussed. Carbon dioxide and methane were observed for the first time as products from dissociation under collisionless conditions. Chapter Three relates an IRMPD experiment of hexafluoropropene. The predominant channel produces CFCF{sub 3} or C{sub 2}F{sub 4} and CF{sub 2}, with the heavier species undergoing further dissociation to two CF{sub 2} fragments. In Chapter Four the ultraviolet (UV) dissociation of hexafluoropropene is investigated. Chapter Five explores the IRMPD of octafluoro-1-butene and octafluoro-2-butene.

Longfellow, C.A. [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry]|[Lawrence Berkeley National Lab., CA (United States). Chemical Sciences Div.

1996-05-01T23:59:59.000Z

490

Fourier Transform Luminescence Spectroscopy of Semiconductor Thin Films and Devices  

SciTech Connect (OSTI)

We have been successful in adapting Fourier transform (FT) Raman accessories and spectrophotometers for sensitive measurements of the photoluminescence (PL) spectra of photovoltaic materials and devices. In many cases, the sensitivity of the FT technique allows rapid room-temperature measurements of weak luminescence spectra that cannot be observed using dispersive PL spectrophotometers. We present here the results of a number of studies of material and device quality obtained using FT-luminescence spectroscopy, including insights into bandgap variations, defect and impurity effects, and relative recombination rates. We also describe our approach to extending the range of the FT-Raman spectrophotometer to cover the region from 11,500 to 3700 cm-1, enabling FT-luminescence measurements to be made from 1.42 to 0.46 eV, and our investigation of FT-PL microspectroscopy.

Webb, J. D.; Keyes, B. M.; Ahrenkiel, R. K.; Wanlass, M. W.; Ramanathan, K.; Gedvilas, L. M.; Olson, M. R.; Dippo, P.; Jones, K. M.

1999-07-12T23:59:59.000Z

491

Quantum Limits and Robustness of Nonlinear Intracavity Absorption Spectroscopy  

E-Print Network [OSTI]

We investigate the limits of intracavity absorption spectroscopy with nonlinear media. Using a common theoretical framework, we compare the detection of a trace gas within an undriven cavity with gain near and above threshold, a driven cavity with gain kept just below threshold, and a cavity driven close to the saturation point of a saturable absorber. These phase-transition-based metrology methods are typically quantum-limited by spontaneous emission, and we compare them to the empty cavity shotnoise-limited case. Although the fundamental limits achievable with nonlinear media do not surpass the empty cavity limits, we show that nonlinear methods are more robust against certain technical noise models. This recognition may have applications in spectrometer design for devices operating in non-ideal field environments.

John K. Stockton; Ari K. Tuchman

2008-10-23T23:59:59.000Z

492

High resolution ion Doppler spectroscopy at Prairie View Rotamak  

SciTech Connect (OSTI)

A fast ion Doppler spectroscopy (IDS) diagnostic system is installed on the Prairie View Rotamak to measure ion temperature and plasma flow. The diagnostic employs a single channel photomultiplier tube and a Jarrell-Ash 50 monochromator with a diffraction grating line density of 1180 lines/mm, which allows for first order spectra of 200-600 nm. The motorized gear of the monochromator allows spectral resolution of 0.01 nm. Equal IDS measurements are observed for various impurity emission lines of which carbon lines exhibit stronger intensities. Furthermore, the diagnostics is examined in an experiment where plasma experiences sudden disruption and quick recovery. In this case, the IDS measurements show {approx}130% increase in ion temperature. Flow measurements are shown to be consistent with plasma rotation.

Houshmandyar, Saeid; Yang Xiaokang [Solar Observatory Department, Prairie View A and M University, Prairie View, Texas 77446 (United States); Magee, Richard [Department of Physics, West Virginia University, Morgantown, West Virginia 26506 (United States)

2012-10-15T23:59:59.000Z

493

Evaluation of oilfield corrosion inhibitors by electrochemical impedance spectroscopy (EIS)  

SciTech Connect (OSTI)

The performance of commercially available oilfield corrosion inhibitors has been evaluated by electrochemical impedance spectroscopy (EIS) in CO{sub 2} saturated 5% sodium chloride solution. The results demonstrate that EIS is a feasible method for ranking oilfield corrosion inhibitor performance, and the inhibitors exhibit inhibition through different mechanisms. EIS can provide information on the inhibited film growth, and generate the parameters which are specific to a particular corrosion inhibition system. It is found that the high breakpoint frequency at 45{degree} phase angle has excellent correlation with the corrosion rate in the inhibited system. The identification of this correlation is significant because there are advantages associated with measuring this parameter. A patent application has been filed for this discovery.

Chen, H.J. [Chevron Petroleum Technology Co., La Habra, CA (United States)

1994-12-31T23:59:59.000Z

494

Nondestructive millimeter wave imaging and spectroscopy using dielectric focusing probes  

SciTech Connect (OSTI)

A tool for interrogating objects over a wide band of frequencies with subwavelength resolution at small standoff distances (near field region) in the transmission mode using a single source and detector measurement setup in the millimeter wave band is presented. The design utilizes optics like principles for guiding electromagnetic millimeter waves from large cross-sectional areas to considerably smaller sub-wavelength areas. While plano-convex lenses can be used to focus waves to a fine resolution, they usually require a large stand-off distance thus resulting in alignment and spacing issues. The design procedure and simulation analysis of the focusing probes are presented in this study along with experimental verification of performance and imaging and spectroscopy examples. Nondestructive evaluation will find benefit from such an apparatus including biological tissue imaging, electronic package integrity testing, composite dielectric structure evaluation for defects and microfluidic sensing.

Hejase, Jose A.; Shane, Steven S.; Park, Kyoung Y.; Chahal, Premjeet [Terahertz Systems Laboratory (TeSLa) - Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI 48823 (United States)

2014-02-18T23:59:59.000Z

495

Laser-induced breakdown spectroscopy (LIBS): a new spectrochemical technique  

SciTech Connect (OSTI)

We have used the breakdown spark from a focused laser beam to generate analytically useful emission spectra of minor constituents in air and other carrier gases. The medium was sampled directly. It was not necessary to reduce the sample to solution nor to introduce electrodes. The apparatus is particularly simple; a pulsed laser, spectrometer, and some method for time resolution. The latter is essential in laser-induced-breakdown spectroscopy (LIBS) because of the strong early continuum. High temperatures in the spark result in vaporization of small particles, dissociation of molecules, and excitation of atomic and ionic spectra, including species which are normally difficult to detect. In one application, we have monitored beryllium in air at conventrations below 1 ..mu..g/m/sup 3/, which is below 1 ppB (w/w). In another we have monitored chlorine and fluorine atoms in real time. LIBS has the potential for real-time direct sampling of contaminants in situ.

Radziemski, L.J.; Loree, T.R.; Cremers, D.A.

1982-01-01T23:59:59.000Z

496

Electron energy loss spectroscopy of gold nanoparticles on graphene  

SciTech Connect (OSTI)

Plasmon excitation decay by absorption, scattering, and hot electron transfer has been distinguished from effects induced by incident photons for gold nanoparticles on graphene monolayer using electron energy loss spectroscopy (EELS). Gold nano-ellipses were evaporated onto lithographed graphene, which was transferred onto a silicon nitride transmission electron microscopy grid. Plasmon decay from lithographed nanoparticles measured with EELS was compared in the absence and presence of the graphene monolayer. Measured decay values compared favorably with estimated radiative and non-radiative contributions to decay in the absence of graphene. Graphene significantly enhanced low-energy plasmon decay, increasing mode width 38%, but did not affect higher energy plasmon or dark mode decay. This decay beyond expected radiative and non-radiative mechanisms was attributed to hot electron transfer, and had quantum efficiency of 20%, consistent with previous reports.

DeJarnette, Drew [Microelectronics and Photonics Graduate Program, University of Arkansas, Fayetteville, Arkansas 72701 (United States); Roper, D. Keith, E-mail: dkroper@uark.edu [Microelectronics and Photonics Graduate Program, University of Arkansas, Fayetteville, Arkansas 72701 (United States); Department of Chemical Engineering, University of Arkansas, Fayetteville, Arkansas 72701 (United States)

2014-08-07T23:59:59.000Z

497

SPECTROSCOPY OF BROAD-LINE BLAZARS FROM 1LAC  

SciTech Connect (OSTI)

We report on optical spectroscopy of 165 flat spectrum radio quasars (FSRQs) in the Fermi 1LAC sample, which have helped allow a nearly complete study of this population. Fermi FSRQs show significant evidence for non-thermal emission even in the optical; the degree depends on the {gamma}-ray hardness. They also have smaller virial estimates of hole mass than the optical quasar sample. This appears to be largely due to a preferred (axial) view of the {gamma}-ray FSRQ and non-isotropic (H/R {approx} 0.4) distribution of broad-line velocities. Even after correction for this bias, the Fermi FSRQs show higher mean Eddington ratios than the optical population. A comparison of optical spectral properties with Owens Valley Radio Observatory radio flare activity shows no strong correlation.

Shaw, Michael S.; Romani, Roger W.; Healey, Stephen E.; Michelson, Peter F. [Department of Physics/KIPAC, Stanford University, Stanford, CA 94305 (United States); Cotter, Garret; Potter, William J. [Department of Astrophysics, University of Oxford, Oxford OX1 3RH (United Kingdom); Readhead, Anthony C. S.; Richards, Joseph L.; Max-Moerbeck, Walter; King, Oliver G. [Department of Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States)

2012-03-20T23:59:59.000Z

498

Constraints on extra dimensions from precision molecular spectroscopy  

E-Print Network [OSTI]

Accurate investigations of quantum level energies in molecular systems are shown to provide a test ground to constrain the size of compactified extra dimensions. This is made possible by the recent progress in precision metrology with ultrastable lasers on energy levels in neutral molecular hydrogen (H$_2$, HD and D$_2$) and the molecular hydrogen ions (H$_2^+$, HD$^+$ and D$_2^+$). Comparisons between experiment and quantum electrodynamics calculations for these molecular systems can be interpreted in terms of probing large extra dimensions, under which conditions gravity will become much stronger. Molecules are a probe of space-time geometry at typical distances where chemical bonds are effective, i.e. at length scales of an \\AA. Constraints on compactification radii for extra dimensions are derived within the Arkani-Hamed-Dimopoulos-Dvali framework, while constraints for curvature or brane separation are derived within the Randall-Sundrum framework. Based on the molecular spectroscopy of D$_2$ molecules an...

Salumbides, E J; Gato-Rivera, B; Ubachs, W

2015-01-01T23:59:59.000Z

499

Graphene as a Substrate To Suppress Fluorescence in Resonance Raman Spectroscopy  

E-Print Network [OSTI]

Resonance Raman spectroscopy (RRS), which can enhance Raman signal by 107 times than normal Raman spectroscopy, is a powerful approach to characterize structures of chemicals (especially biomolecules) at low concentrations.1-4 However, fluorescence (FL) background is a major obstacle in RRS because the FL cross section (?10-16 cm2) is much larger than the RRS cross section (?10-22 cm2).3 Several approaches, such as ultraviolet RRS (UV-RRS),1 time-resolved Raman detection,5,6 femtosecond broadband stimu-lated Raman spectroscopy (FSRS),7 and coherent anti-Stokes Raman spectroscopy (CARS),8 have been used to suppress or reject FL background in RRS. However, these approaches need expensive and complex equipments and have other limitations, such as sample degradation in UV-RRS. Surface-enhanced Raman spectroscopy (SERS) is another powerful approach to characterize structures of chemicals at extremely low concentrations or even at the single

Liming Xie; Xi Ling; Yuan Fang; Jin Zhang; Zhongfan Liu

2009-01-01T23:59:59.000Z

500

Photofragment translational spectroscopy of three body dissociations and free radicals  

SciTech Connect (OSTI)

This dissertation describes several three-body dissociations and the photodissociation of methyl radicals studied using photofragment translational spectroscopy. The first chapter provides an introduction to three body dissociation, examines current experimental methodology, and includes a discussion on the treatment of photofragment translational spectroscopy data arising from three-body fragmentation. The ultraviolet photodissociation of azomethane into two methyl radicals and nitrogen is discussed in chapter 2. Chapter 3 describes the photodissociation of acetone at 248 nm and 193 nm. At 248 nm the translational energy release from the initial C-C bond cleavage matches the exit barrier height and a comparison with results at 266 nm suggests that is invariant to the available energy. A fraction of the nascent CH{sub 3}CO radicals spontaneously dissociate following rotational averaging. The for the second C-C bond cleavage also matches the exit barrier height. At 193 nm the experimental data can be successfully fit assuming that the dynamics are analogous to those at 248 nm. A simplified model of energy partitioning which adequately describes the experimental results is discussed. Experiments on acetyl halides provide additional evidence to support the proposed acetone dissociation mechanism. A value of 17.0{+-}1.0 kcal/mole for the barrier height, CH{sub 3}CO decomposition has been determined. The photodissociation of methyl radical at 193 nm and 212.8 nm is discussed in the chapter 5. The formation of CH{sub 2} ({sup 1}A{sub l}) and H ({sup 2}S) was the only single photon dissociation pathway observed at both wavelengths.

North, S.W.

1995-04-01T23:59:59.000Z