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1

Angle-resolved photoemission spectroscopy (ARPES) studies of cuprate superconductors  

SciTech Connect

This dissertation is comprised of three different angle-resolved photoemission spectroscopy (ARPES) studies on cuprate superconductors. The first study compares the band structure from two different single layer cuprates Tl{sub 2}Ba{sub 2}CuO{sub 6+{delta}} (Tl2201) T{sub c,max} {approx} 95 K and (Bi{sub 1.35}Pb{sub 0.85})(Sr{sub 1.47}La{sub 0.38})CuO{sub 6+{delta}} (Bi2201) T{sub c,max} {approx} 35 K. The aim of the study was to provide some insight into the reasons why single layer cuprate's maximum transition temperatures are so different. The study found two major differences in the band structure. First, the Fermi surface segments close to ({pi},0) are more parallel in Tl2201 than in Bi2201. Second, the shadow band usually related to crystal structure is only present in Bi2201, but absent in higher T{sub c} Tl2201. The second study looks at the different ways of doping Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} (Bi2212) in-situ by only changing the post bake-out vacuum conditions and temperature. The aim of the study is to systematically look into the generally overlooked experimental conditions that change the doping of a cleaved sample in ultra high vacuum (UHV) experiments. The study found two major experimental facts. First, in inadequate UHV conditions the carrier concentration of Bi2212 increases with time, due to the absorption of oxygen from CO{sub 2}/CO molecules, prime contaminants present in UHV systems. Second, in a very clean UHV system at elevated temperatures (above about 200 K), the carrier concentration decreases due to the loss of oxygen atoms from the Bi-O layer. The final study probed the particle-hole symmetry of the pseudogap phase in high temperature superconducting cuprates by looking at the thermally excited bands above the Fermi level. The data showed a particle-hole symmetric pseudogap which symmetrically closes away from the nested FS before the node. The data is consistent with a charge density wave (CDW) origin of the pseudogap, similar to STM checkerboard patterns in the pseudogap state.

Palczewski, Ari Deibert

2010-12-15T23:59:59.000Z

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 BaNi2P2 observed by angle-resolved photoemission spectroscopy  

Science Journals Connector (OSTI)

We have performed an angle-resolved photoemission spectroscopy (ARPES) study of BaNi2P2 that shows a superconducting transition at Tc ? 2.5 K. We observed hole and electron Fermi surfaces (FSs) around the Brillouin zone center and corner, respectively, and the shapes of the hole FSs dramatically changed with photon energy, indicating strong three dimensionality. The observed FSs are consistent with band-structure calculations and de Haas-van Alphen measurements. The mass enhancement factors estimated in the normal state were m*/mb ? 2, indicating weak electron correlation compared to typical iron-pnictide superconductors. An electronlike Fermi surface around the Z point was observed in contrast with BaNi2As2 and may be related to the higher Tc of BaNi2P2.

S. Ideta; T. Yoshida; M. Nakajima; W. Malaeb; H. Kito; H. Eisaki; A. Iyo; Y. Tomioka; T. Ito; K. Kihou; C. H. Lee; Y. Kotani; K. Ono; S. K. Mo; Z. Hussain; Z.-X. Shen; H. Harima; S. Uchida; A. Fujimori

2014-05-28T23:59:59.000Z

4

Tunable VUV laser based spectrometer for Angle Resolved Photoemission Spectroscopy (ARPES)  

E-Print Network (OSTI)

We have developed an angle-resolved photoemission spectrometer with tunable VUV 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 5.3eV and 7eV. The most important part of the set-up is a compact, vacuum enclosed fourth harmonic generator based on KBBF crystals, grown hydrothermally in the US. This source can deliver a photon flux of over 10^14 photons/s. We demonstrate that this energy range is sufficient to measure the kz dispersion in an iron arsenic high temperature superconductor, which was previously only possible at synchrotron facilities.

Jiang, Rui; Wu, Yun; Huang, Lunan; McMillen, Colin D; Kolis, Joseph; Giesber, Henry G; Egan, John J; Kaminski, Adam

2014-01-01T23:59:59.000Z

5

Angle-Resolved Photoemission Spectroscopy on Electronic Structure and Electron-Phonon Coupling in Cuprate Superconductors  

SciTech Connect

In addition to the record high superconducting transition temperature (T{sub c}), high temperature cuprate superconductors are characterized by their unusual superconducting properties below T{sub c}, and anomalous normal state properties above T{sub c}. In the superconducting state, although it has long been realized that superconductivity still involves Cooper pairs, as in the traditional BCS theory, the experimentally determined d-wave pairing is different from the usual s-wave pairing found in conventional superconductors. The identification of the pairing mechanism in cuprate superconductors remains an outstanding issue. The normal state properties, particularly in the underdoped region, have been found to be at odd with conventional metals which is usually described by Fermi liquid theory; instead, the normal state at optimal doping fits better with the marginal Fermi liquid phenomenology. Most notable is the observation of the pseudogap state in the underdoped region above T{sub c}. As in other strongly correlated electrons systems, these unusual properties stem from the interplay between electronic, magnetic, lattice and orbital degrees of freedom. Understanding the microscopic process involved in these materials and the interaction of electrons with other entities is essential to understand the mechanism of high temperature superconductivity. Since the discovery of high-T{sub c} superconductivity in cuprates, angle-resolved photoemission spectroscopy (ARPES) has provided key experimental insights in revealing the electronic structure of high temperature superconductors. These include, among others, the earliest identification of dispersion and a large Fermi surface, an anisotropic superconducting gap suggestive of a d-wave order parameter, and an observation of the pseudogap in underdoped samples. In the mean time, this technique itself has experienced a dramatic improvement in its energy and momentum resolutions, leading to a series of new discoveries not thought possible only a decade ago. This revolution of the ARPES technique and its scientific impact result from dramatic advances in four essential components: instrumental resolution and efficiency, sample manipulation, high quality samples and well-matched scientific issues. The purpose of this treatise is to go through the prominent results obtained from ARPES on cuprate superconductors. Because there have been a number of recent reviews on the electronic structures of high-T{sub c} materials, we will mainly present the latest results not covered previously, with a special attention given on the electron-phonon interaction in cuprate superconductors. What has emerged is rich information about the anomalous electron-phonon interaction well beyond the traditional views of the subject. It exhibits strong doping, momentum and phonon symmetry dependence, and shows complex interplay with the strong electron-electron interaction in these materials. ARPES experiments have been instrumental in identifying the electronic structure, observing and detailing the electron-phonon mode coupling behavior, and mapping the doping evolution of the high-T{sub c} cuprates. The spectra evolve from the strongly coupled, polaronic spectra seen in underdoped cuprates to the Migdal-Eliashberg like spectra seen in the optimally and overdoped cuprates. In addition to the marked doping dependence, the cuprates exhibit pronounced anisotropy with direction in the Brillouin zone: sharp quasiparticles along the nodal direction that broaden significantly in the anti-nodal region of the underdoped cuprates, an anisotropic electron-phonon coupling vertex for particular modes identified in the optimal and overdoped compounds, and preferential scattering across the two parallel pieces of Fermi surface in the antinodal region for all doping levels. This also contributes to the pseudogap effect. To the extent that the Migdal-Eliashberg picture applies, the spectra of the cuprates bear resemblance to that seen in established strongly coupled electron-phonon superconductors such as Pb. On the other

Zhou, X.J.

2010-04-30T23:59:59.000Z

6

Controlling the Carrier Concentration of the High-Temperature Superconductor Bi2Sr2CaCu2O8+? in Angle-resolved Photoemission Spectroscopy Experiments  

SciTech Connect

We study the variation of the electronic properties at the surface of a high-temperature superconductor as a function of vacuum conditions in angle-resolved photoemission spectroscopy experiments. Normally, under inadequate ultrahigh vacuum (UHV) conditions the carrier concentration of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} (Bi2212) increases with time due to the absorption of oxygen from CO{sub 2}/CO molecules that are prime contaminants present in UHV systems. We find that in an optimal vacuum environment at low temperatures, the surface of Bi2212 is quite stable (the carrier concentration remains constant); however at elevated temperatures the carrier concentration decreases due to the loss of oxygen atoms from the Bi-O layer. These two effects can be used to control the carrier concentration in situ. Our finding opens the possibility of studying the electronic properties of the cuprates as a function of doping across the phase diagram on the same surface of sample (i.e., with the same impurities and nondopant defects). We envision that this method could be utilized in other surface sensitive techniques such as scanning tunneling microscopy/spectroscopy.

Palczewski, A.D.; Wen, J.; Kondo, T.; Xu, G.Z.J., Gu, G; Kaminski, A.

2010-03-19T23:59:59.000Z

7

Rapid high-resolution spin- and angle-resolved photoemission spectroscopy with pulsed laser source and time-of-flight spectrometer  

SciTech Connect

A high-efficiency spin- and angle-resolved photoemission spectroscopy (spin-ARPES) spectrometer is coupled with a laboratory-based laser for rapid high-resolution measurements. The spectrometer combines time-of-flight (TOF) energy measurements with low-energy exchange scattering spin polarimetry for high detection efficiencies. Samples are irradiated with fourth harmonic photons generated from a cavity-dumped Ti:sapphire laser that provides high photon flux in a narrow bandwidth, with a pulse timing structure ideally matched to the needs of the TOF spectrometer. The overall efficiency of the combined system results in near-E{sub F} spin-resolved ARPES measurements with an unprecedented combination of energy resolution and acquisition speed. This allows high-resolution spin measurements with a large number of data points spanning multiple dimensions of interest (energy, momentum, photon polarization, etc.) and thus enables experiments not otherwise possible. The system is demonstrated with spin-resolved energy and momentum mapping of the L-gap Au(111) surface states, a prototypical Rashba system. The successful integration of the spectrometer with the pulsed laser system demonstrates its potential for simultaneous spin- and time-resolved ARPES with pump-probe based measurements.

Gotlieb, K. [Graduate Group in Applied Science and Technology, University of California, Berkeley, California 94720 (United States)] [Graduate Group in Applied Science and Technology, University of California, Berkeley, California 94720 (United States); Hussain, Z.; Bostwick, A.; Jozwiak, 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); Lanzara, A. [Department of Physics, University of California, Berkeley, California 94720, USA and Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)] [Department of Physics, University of California, Berkeley, California 94720, USA and Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

2013-09-15T23:59:59.000Z

8

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

NLE Websites -- All DOE Office Websites (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...

9

Hydrogen chemisorption on Si(111)7×7 studied with surface-sensitive core-level spectroscopy and angle-resolved photoemission  

Science Journals Connector (OSTI)

Photoelectron spectroscopy of the Si 2p core level has been performed in order to determine surface core-level shifts for the Si(111)‘‘7×1’’:H and Si(111)7×7 surfaces, as well as to determine the Fermi-level position in the bulk band gap for the ‘‘7×1’’:H surface. Angle-resolved ultraviolet photoelectron spectroscopy has been used to determine the initial energy versus k-parallel dispersion for the surface state on the hydrogen-exposed surface. The results of these measurements imply that the monohydride phase is formed within the 7×7 unit cell after the hydrogen exposure. The core-level spectroscopy results obtained for the 7×7 surface are in good qualitative agreement with earlier results, but we suggest, in contradiction to a previous interpretation, that the surface component which shifted to lower binding energy corresponds to the rest atoms and not to the adatoms.

C. J. Karlsson; E. Landemark; L. S. O. Johansson; U. O. Karlsson; R. I. G. Uhrberg

1990-01-15T23:59:59.000Z

10

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

SciTech Connect

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

11

Angle-resolved photoemission studies of single-crystal YBa2Cu3O7-x  

Science Journals Connector (OSTI)

We present the first angle-resolved photoemission and low-energy electron-diffraction (LEED) results obtained from clean single-crystal YBa2Cu3O7-x (001) surfaces prepared by cleaving in a vacuum. The surfaces exhibit (1×1)-ordered LEED patterns, but many of the photoemission features exhibit little or no angular dependence. The most important exception is the upper spectral edge, which shows angular dispersion and a strong photon energy dependence.

N. G. Stoffel; Y. Chang; M. K. Kelly; L. Dottl; M. Onellion; P. A. Morris; W. A. Bonner; G. Margaritondo

1988-05-01T23:59:59.000Z

12

Electronic structure of HfN0.93(100) studied by angle-resolved photoemission  

Science Journals Connector (OSTI)

An experimental and theoretical study of the electronic structure of HfN is reported. Results from angle-resolved photoemission experiments on HfN0.93(100) are presented and interpreted with use of calculated results. The bulk-band structure of stoichiometric HfN was calculated relativistically and nonrelativistically using the linear augmented-plane-wave method. Predicted band locations and dispersions along the ?–X direction are compared with experimental results. In general the experiment indicates smaller bandwidths and locates the bands deeper below the Fermi level than the calculated values. Calculations of photoemission spectra, made nonrelativistically, are also reported and these spectra are found to reflect the recorded spectra fairly well.

J. Lindström; L. I. Johansson; P. E. S. Persson; A. Callens; D. S. L. Law; A. N. Christensen

1989-02-15T23:59:59.000Z

13

The UHV Experimental Chamber For Optical Measurements (Reflectivity and Absorption) and Angle Resolved Photoemission of the BEAR Beamline at ELETTRA  

SciTech Connect

The experimental station of the BEAR (Bending magnet for Emission, Absorption and Reflectivity) beamline at ELETTRA (Trieste, Italy) is an UHV chamber conceived to fully exploit the spectroscopic possibilities offered by the light spot produced by the beamline. Spectroscopies include reflectivity ({theta}-2{theta} and diffuse), optical absorption, fluorescence and angle resolved photoemission. The chamber can be rotated around the beam axis to select the s (TE) or p (TM) incidence conditions and/or the position of the ellipse of polarization with respect to the sample. Photon detectors (e.g. photodiodes) and electron detector (hemispherical analyzer - 1 deg. angular resolution, 20 meV energy resolution) cover about completely the full 2{pi} solid angle above the sample surface in any light incidence condition.

Pasquali, L.; Nannarone, S. [UdR-INFM Modena, Universita di Modena and Reggio Emilia, Via Vignolese 905, 41100 Modena (Italy); Dipartimento di Ingegneria dei Materiali e dell'Ambiente, Universita di Modena and Reggio Emilia, Via Vignolese 905, 41100 Modena (Italy); De Luisa, A. [TASC-INFM, MM building in Area Science Park, s.s.14 km 163.5, 34012 Basovizza, Trieste (Italy)

2004-05-12T23:59:59.000Z

14

E-Print Network 3.0 - angled-resolved photoelectron spectroscopy...  

NLE Websites -- All DOE Office Websites (Extended Search)

state was visible by angle-resolved valence band photoelectron spectroscopy, and that the LEED... -dependence of the ... Source: Ortega, Enrique - Donostia International Physics...

15

A New Spin on Photoemission Spectroscopy  

SciTech Connect

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

16

Angle-resolved photoemission study of the (100) surface of a ZrN0.93 single crystal  

Science Journals Connector (OSTI)

The (100) surface of a ZrN0.93 single crystal has been studied using angle-resolved photoemission and synchrotron radiation. A mapping of the bulk-band structure is presented and compared with an augmented-plane-wave band structure, calculated for stoichiometric composition. The experimentally determined bands are found to be located deeper below the Fermi energy than the calculated bands but the dispersions agree fairly well. A surface state is observed at 3.8 eV binding energy, for photon energies below 24 eV, and a structure interpreted as arising from vacancy induced states is observed at a binding energy of 2.1 eV for photon energies above 30 eV. The latter structure is found to exhibit a strong intensity modulation with photon energy. This intensity modulation is compared with the resonance enhancement observed in the emission from states just below the Fermi energy above the Zr 4p absorption threshold.

J. Lindström; L. I. Johansson; A. Callens; D. S. L. Law; A. N. Christensen

1987-05-15T23:59:59.000Z

17

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

SciTech Connect

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

18

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

SciTech Connect

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

19

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

NLE Websites -- All DOE Office Websites (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...

20

Spin- and angle-resolved photoemission study of chemisorbed p(1×1) O on epitaxial ultrathin Fe/W(001) films  

Science Journals Connector (OSTI)

Chemisorbed p(1×1) oxygen on ultrathin epitaxial Fe films grown on W(001) are studied using spin- and angle-resolved photoemission. In agreement with theoretical predictions, single-monolayer (ML) Fe films on W(001) are found to be nonmagnetic; 2-ML-thick Fe films are magnetic, and chemisorbed p(1×1) oxygen does not destroy the magnetism. Even- and odd-symmetry oxygen 2p-derived bands are measured along the ?¯-X¯ and ?¯-M¯ directions of the two-dimensional Brillouin zone. Oxygen-derived features in the photoemission spectra exhibit magnetic exchange splitting as well as spin-dependent intrinsic linewidths that are governed by lifetime effects and initial-state mixing with Fe bands. Oxygen 2p-band narrowing resulting from the expanded Fe thin-film lattice constant is observed. The results are compared with relevant calculations and corresponding experimental studies of p(1×1) oxygen on bulk Fe(001) surfaces.

R. L. Fink; G. A. Mulhollan; A. B. Andrews; J. L. Erskine; G. K. Walters

1992-05-01T23:59:59.000Z

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

Emergence of multiple Fermi surface maps in angle-resolved photoemission from Bi2Sr2CaCu2O8+?  

Science Journals Connector (OSTI)

We report angle-resolved photoemission spectra (ARPES) for emission from the Fermi energy (EF) over a large area of the (kx,ky) plane using 21.2 and 32 eV photon energies in two distinct polarizations from an optimally doped single crystal of Bi2Sr2CaCu2O8+? (Bi2212), together with extensive first-principles simulations of the ARPES intensities. The results display a wide-ranging level of accord between theory and experiment, demonstrating that the ARPES matrix elements can produce a striking variety of Fermi surface maps, especially in the presence of secondary features arising from modulations of the underlying tetragonal system. Our analysis demonstrates how the energy and polarization dependency of the ARPES matrix element can help to disentangle the primary contributions to the spectrum from the secondary features and indicates that secondary features reflect a direct modulation of the CuO2 planes.

M. C. Asensio; J. Avila; L. Roca; A. Tejeda; G. D. Gu; M. Lindroos; R. S. Markiewicz; A. Bansil

2003-01-22T23:59:59.000Z

22

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

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

23

Site-selectivity properties of the angle-resolved photoemission matrix element in Bi2Sr2CaCu2O8  

Science Journals Connector (OSTI)

We show that the angle-resolved photoemission (ARPES) spectra for emission from the bonding as well as the antibonding Fermi-surface sheet in Bi2Sr2CaCu2O8 possess remarkable site, selectivity properties, in that the emission for photon energies less than 25 eV is dominated by p?d excitations from just the O sites in the CuO2 planes. There is little contribution from Cu electrons to the ARPES intensity, even though the initial states at the Fermi energy contain an admixture of Cu-d and O-p electrons. We analyze the origin of this effect by considering the nature of the associated dipole matrix element in detail and find that various possible transition channels (other than p?d on O sites) are effectively blocked by the fact that the related radial cross section is small and/or a lack of available final states. Our prediction that ARPES can preferentially sample Cu or O states by tuning the photon energy suggests different possibilities for exploiting energy dependent ARPES spectra for probing initial state characters in the cuprates.

S. Sahrakorpi; M. Lindroos; A. Bansil

2003-08-22T23:59:59.000Z

24

Development of a high-resolution soft x-ray (30--1500 eV) beamline at the Advanced Light Source and its use for the study of angle-resolved photoemission extended fine structure  

SciTech Connect

ALS Bending magnet beamline 9.3.2 is for high resolution spectroscopy, with circularly polarized light. Fixed included-angle SGM uses three gratings for 30--1500 eV photons; circular polarization is produced by an aperture for selecting the beam above or below the horizontal plane. Photocurrent from upper and lower jaws of entrance slit sets a piezoelectric drive feedback loop on the vertically deflecting mirror for stable beam. End station has a movable platform. With photomeission data from Stanford, structure of c(2{times}2)P/Fe(100) was determined using angle-resolved photoemission extended fine structure (ARPEFS). Multiple-scattering spherical-wave (MSSW) calculations indicate that P atoms adsorb in fourfold hollow sites 1.02A above the first Fe layer. Self-consistent-field X{alpha} scattered wave calculation confirm that the Fe{sub 1}-Fe{sub 2} space is contracted for S/Fe but not for P/Fe; comparison is made to atomic N and O on Fe(100). Final-state effects on ARPEFS curves used literature data from the S 1s and 2p core levels of c(2{times}2)S/Ni(001); a generalized Ramsauer-Townsend splitting is present in the 1s but not 2p data. An approximate method for analyzing ARPEFS data from a non-s initial state using only the higher-{ell} partial wave was tested successfully. ARPEFS data from clean surfaces were collected normal to Ni(111) (3p core levels) and 5{degree} off-normal from Cu(111)(3s, 3p). Fourier transforms (FT) resemble adsorbate systems, showing backscattering signals from atoms up to 4 layers below emitters. 3p FTs show scattering from 6 nearest neighbors in the same crystal layer as the emitters. MSSW calulation indicate that Cu 3p photoemission is mostly d-wave. FTs also indicate double-scattering and single-scattering from laterally distant atoms; calculations indicate that the signal is dominated by photoemission from the first 2 crystal layers.

Huff, W.R.A. [California Univ., Berkeley, CA (United States). Dept. of Chemistry]|[Lawrence Berkeley National Lab., CA (United States)

1996-02-01T23:59:59.000Z

25

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

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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...

26

Exploring Competing Orders in the High-Tc Cuprate Phase Diagram Using Angle Resolved Photoemission Spectroscopy  

E-Print Network (OSTI)

state of Cu-O high-temperature superconductors. Phys. Rev.coupling in high- temperature superconductors. Nature 412,Pseudogap in the High-Temperature Superconductor HoBa 2 Cu 4

Garcia, Daniel Robert

2010-01-01T23:59:59.000Z

27

Cryogenic growth of Al nitride on GaAs(110): X-ray-photoemission spectroscopy and inverse-photoemission spectroscopy  

Science Journals Connector (OSTI)

We report on our recent studies of Al nitride growth on GaAs(110) formed by depositing Al onto a condensed ammonia overlayer on GaAs(110) at T=90 K using x-ray-photoemission spectroscopy and inverse-photoemission spectroscopy. We have also investigated the temperature dependence of the interface thus formed. The results show some limited amount of Al nitride formed at T=90 K even though the reaction is slow, but the overlayer mostly remains metallic until the substrate is heated up. Much of the reaction of Al with ammonia occurs at about T=170 K, above which the overlayer becomes insulating. The combined information from occupied and unoccupied states reveals new features of the interface formation, and is consistent with our previous synchrotron photoemission studies of Al/NH3/GaAs(100).

Ken T. Park and Y. Gao

1993-02-15T23:59:59.000Z

28

Angle-resolved photoemission spectra of the Hubbard model  

Science Journals Connector (OSTI)

We discuss spectra calculated for the two-dimensional Hubbard model in the intermediate coupling regime with the dynamical cluster approximation, which is a nonperturbative approach. We find a crossover from a normal Fermi liquid with a Fermi surface closed around the Brillouin-zone center at large doping to a non-Fermi liquid for small doping where the Fermi surface is holelike, closed around M=(?,?). The topology of the Fermi surface at low doping indicates a violation of Luttinger’s theorem. We discuss different ways of presenting the spectral data to extract information about the Fermi surface. A comparison to recent experiments is presented.

Th. A. Maier; Th. Pruschke; M. Jarrell

2002-08-01T23:59:59.000Z

29

Magnetic dichroism in valence-band x-ray photoemission spectroscopy  

Science Journals Connector (OSTI)

A fully relativistic description of spin-resolved valence-band x-ray photoemission spectroscopy (VB-XPS) of magnetic solids is presented that is based on multiple scattering theory. This approach allows us to investigate possible magnetic dichroism in VB-XPS. As is demonstrated by results for CoxPt1-x, application to disordered alloys is straightforward within the framework of the coherent potential approximation alloy theory. The spin-integrated spectra for unpolarized radiation were found to be in very satisfying agreement with corresponding experimental data. For the spin-resolved spectra a pronounced magnetic circular dichroism is predicted that should be easily observed.

H. Ebert and J. Schwitalla

1997-02-01T23:59:59.000Z

30

Two-photon Photo-emission of Ultrathin Film PTCDA Morphologies on Ag(111)  

E-Print Network (OSTI)

Two-photon Photo-emission of Ultrathin Film PTCDAwith angle-resolved two-photon photo- emission. In Stranski-probe laser pulse, h? 2 , photo-emits the electron. research

Yang, Aram

2008-01-01T23:59:59.000Z

31

Ga configurations in hydrogenated amorphous silicon as studied by x-ray photoemission spectroscopy  

Science Journals Connector (OSTI)

Samples of crystalline silicon and glow-discharge-deposited hydrogenated amorphous silicon were doped with gallium by low-energy (4-keV) ion implantation. X-ray photoemission spectroscopy was used to study the chemical-bonding states of the Ga. From Ga 3d core-level studies, we found that elementary interstitial, threefold-coordinated, and fourfold-coordinated Ga coexist in the ion-implanted and annealed amorphous silicon network. The percentage of activated threefold- and fourfold-coordinated Ga atoms is found to increase with increasing annealing temperature, prior to crystallization. The energy released by the amorphous silicon lattice upon annealing contributes to the activation of the gallium from the elementary state to the threefold- or fourfold-coordinated state. No evidence of Ga-H bond formation is found. The percentage of fourfold-coordinated Ga, which we call the doping efficiency, ranges from 5% to 10%, depending upon the thermal treatment.

Z. H. Lu; S. Poulin-Dandurand; E. Sacher; A. Yelon

1990-09-15T23:59:59.000Z

32

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

NLE Websites -- All DOE Office Websites (Extended Search)

Where Metals, semiconductors, molecules, surfaces, nanosystems... : double phase transition (Morin 59) Tc 340 K ... Source: Botti, Silvana - Laboratoire des Solides...

33

THE DETERMINATION OF ELECTRONIC STATES IN CRYSTALLINE SEMICONDUCTORS AND METALS BY ANGLE RESOLVED PHOTOEMISSION  

E-Print Network (OSTI)

high density of states, midway along the r-K line. peaks areconduction band quite well midway along A, where much of thelower binding energies midway along A than is theoretically

Mills, K.A.

2010-01-01T23:59:59.000Z

34

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.

35

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

NLE Websites -- All DOE Office Websites (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...

36

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

NLE Websites -- All DOE Office Websites (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...

37

Hall coefficient and angle-resolved photoemission in systems with strong pair fluctuations  

Science Journals Connector (OSTI)

We examine the normal-state temperature and doping dependence of the Hall coefficient in the context of a pair-fluctuation scenario, based on a model where itinerant electrons are hybridized with localized electron pairs via a charge exchange term. We show that an anomalous behavior of the Hall effect, qualitatively similar to that observed in high-Tc superconductors, can be attributed to the non-Fermi-liquid properties of the single-particle spectral function that exhibits pseudogap features. Our calculations are based on a dynamical mean-field procedure that relates the transport coefficients to the single-particle spectral function in an exact way.

Alfonso Romano and Julius Ranninger

2000-08-01T23:59:59.000Z

38

Widespread spin polarization effects in photoemission from topological insulators  

SciTech Connect

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

39

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

SciTech Connect

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

40

High-resolution photoemission spectroscopy study of clean and Au-nanowire-decorated Si(5 5 12) surfaces  

Science Journals Connector (OSTI)

We have examined the Si 2p photoemission line shape of the clean Si(5 5 12)2×1 surface in detail and have investigated the evolution of the Au-induced nanowires on this surface at different temperatures with low-energy-electron diffraction and photoemission spectroscopy. The Si 2p spectra from the clean 2×1 surface exhibit very complex line shapes composed at least of five different surface-related components. Possible origins of the most distinct surface component with a surface core-level shift of -0.62 eV are discussed within the three different structure models proposed so far. Upon Au deposition, the intensity of that particular surface component was largely reduced indicating that the Au adsorbates interact dominantly with the specific Si surface atoms related. With an annealing above 500°C after Au deposition of 0.2 ML, the surface drastically changes into a metallic phase, as shown clearly in the valence band photoemission spectra, along with the gradual formation of the (337)×2 facets observed in LEED. In this transition, a new Au 4f component appears while the Si 2p core-level spectra keep alike. This indicates that the surface metallization involves the rearrangement of Au adsorbates, possibly the formation of new Au chains on the surface.

J. R. Ahn; W. H. Choi; Y. K. Kim; H. S. Lee; H. W. Yeom

2003-10-15T23:59:59.000Z

Note: This page contains sample records for the topic "angle-resolved photoemission spectroscopy" from the National Library of EnergyBeta (NLEBeta).
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41

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

SciTech Connect

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

42

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

NLE Websites -- All DOE Office Websites (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...

43

Dynamics and Spatial Distribution of Electrons in Quantum Wells at Interfaces Determined by Femtosecond Photoemission Spectroscopy  

SciTech Connect

The dynamics of excited electrons in insulator quantum well states on a metal substrate were determined by femtosecond two-photon photoemission for the first time. Lifetimes are reported for the first three excited states for 1{endash}6 atomic layers of Xe on Ag(111). As the image states evolve into quantum well states with increasing coverage, the lifetimes undergo an oscillation as the layer boundary crosses each node of the wave function. The lifetime data are modeled by extending the two-band nearly free-electron approximation to account for the presence of a dielectric layer. The lifetimes are shown to depend on the spatial distribution of the interfacial electron. {copyright} {ital 1997} {ital The American Physical Society}

McNeill, J.D.; Lingle, R.L. Jr.; Ge, N.; Wong, C.M.; Jordan, R.E.; Harris, C.B. [Department of Chemistry, University of California, Berkeley, California 94720, and Chemical Sciences Division, Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)] [Department of Chemistry, University of California, Berkeley, California 94720, and Chemical Sciences Division, Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

1997-12-01T23:59:59.000Z

44

Time dependence of FEL-induced surface photovoltage on semiconductor interfaces measured with synchroton radiation photoemission spectroscopy  

SciTech Connect

During the last year, the first surface science experiments simultaneously using a Free Electron Laser (FEL) and Synchrotron Radiation (SR) have been performed on SuperACO at LURE (Orsay, France). These {open_quotes}two color{close_quotes} experiments studied the surface photovoltage (SPV) induced on semiconductor surfaces and interfaces by the SuperACO FEL, a storage ring FEL delivering 350 nm photons which am naturally synchronized with the SR; the SPV was measured by synchrotron radiation core-level photoemission spectroscopy on the high-resolution SU3 undulator beamline. We will describe the experimental setup, which allowed us to convey the FEL light onto the samples sitting in the SU3 experimental station by means of a series of mirrors, and show the results we obtained for prototypical systems such as Ag/GaAs(110) and Si(111) 2 x 1. The dependence of the SPV was studied in function of various parameters, changing sample doping and photon flux; but our efforts were mainly devoted to studying its dependence on the time delay between the FEL pump and the SR probe. On SuperACO, such delay can be varied between 1 and 120 ns, the limits being given by the time duration of a SR pulse and by the interval between two consecutive positron bunches, respectively. The results show a clear temporal dependence of the amount of SPV on cleaved Si surfaces, where as the Ag/GaAs(110) does not show any difference on the ns time scale. We will discuss these results in terms of the role of surface recombination in the dynamics of the photoinduced electron-hole pairs. These studies follow the evolution of the density of electrostatic charge at surfaces and interfaces on a nanosecond time scale, and might pave the way for a new series of experiments: for example, one might explore what are the physical mechanisms limiting the time response of Schottky diodes.

Marsi, M. [Ecole Polytechnique Federale de Lausanne (Switzerland); Delboulbe, A.; Garzella, D. [Universite de Paris-Sud, Orsay (France)] [and others

1995-12-31T23:59:59.000Z

45

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

SciTech Connect

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

46

Magnetic dichroism in valence-band photoemission spectroscopy of disordered bcc FexCo1-x alloys  

Science Journals Connector (OSTI)

A fully relativistic calculation of spin-resolved valence-band photoemission spectra for bcc FexCo1-x alloys is presented that is based on the Korringa-Kohn-Rostoker coherent-potential approximation method of band-structure calculation. The result for the spin-integrated spectra for unpolarized radiation was found to be in very satisfying agreement with corresponding experimental data. For the spin-resolved spectra a pronounced magnetic circular dichroism is predicted that should be observable in a corresponding experiment.

S. Ostanin and H. Ebert

1998-11-01T23:59:59.000Z

47

Gantry-angle resolved VMAT pretreatment verification using EPID image prediction  

SciTech Connect

Purpose: Pretreatment verification of volumetric modulated arc therapy (VMAT) dose delivery with electronic portal imaging device (EPID) uses images integrated over the entire delivery or over large subarcs. This work aims to develop a new method for gantry-angle-resolved verification of VMAT dose delivery using EPID.Methods: An EPID dose prediction model was used to calculate EPID images as a function of gantry angle for eight prostate patient deliveries. EPID image frames at 7.5 frames per second were acquired during delivery via a frame-grabber system. The gantry angle for each image was encoded in kV frames which were synchronized to the MV frames. Gamma analysis results as a function of gantry angle were assessed by integrating the frames over 2° subarcs with an angle-to-agreement tolerance of 0.5° about the measured image angle.Results: The model agreed with EPID images integrated over the entire delivery with average Gamma pass-rates at 2%, 2 mm of 99.7% (10% threshold). The accuracy of the kV derived gantry angle for each image was found to be 0.1° (1 SD) using a phantom test. For the gantry-resolved analysis all Gamma pass-rates were greater than 90% at 3%, 3 mm criteria (with only two exceptions), and more than 90% had a 95% pass-rate, with an average of 97.3%. The measured gantry angle lagged behind the predicted angle by a mean of 0.3°± 0.3°, with a maximum lag of 1.3°.Conclusions: The method provides a comprehensive and highly efficient pretreatment verification of VMAT delivery using EPID. Dose delivery accuracy is assessed as a function of gantry angle to ensure accurate treatment.

Woodruff, Henry C.; Rowshanfarzad, Pejman [School of Mathematical and Physical Sciences, The University of Newcastle, NSW 2308 (Australia)] [School of Mathematical and Physical Sciences, The University of Newcastle, NSW 2308 (Australia); Fuangrod, Todsaporn [School of Electrical Engineering and Computer Science, The University of Newcastle, NSW 2308 (Australia)] [School of Electrical Engineering and Computer Science, The University of Newcastle, NSW 2308 (Australia); McCurdy, Boyd M. C. [Division of Medical Physics, CancerCare Manitoba, 675 McDermot Avenue, Winnipeg, Manitoba R3E 0V9 (Canada) [Division of Medical Physics, CancerCare Manitoba, 675 McDermot Avenue, Winnipeg, Manitoba R3E 0V9 (Canada); Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba R3T 2N2 (Canada); Department of Radiology, University of Manitoba, Winnipeg, Manitoba R3T 2N2 (Canada); Greer, Peter B. [School of Mathematical and Physical Sciences, The University of Newcastle, NSW 2308, Australia and Department of Radiation Oncology, Calvary Mater Newcastle Hospital, Locked Bag 7, Hunter region Mail Centre, Newcastle, NSW 2310 (Australia)] [School of Mathematical and Physical Sciences, The University of Newcastle, NSW 2308, Australia and Department of Radiation Oncology, Calvary Mater Newcastle Hospital, Locked Bag 7, Hunter region Mail Centre, Newcastle, NSW 2310 (Australia)

2013-08-15T23:59:59.000Z

48

PASSIVATION OF SEMICONDUCTOR SURFACES FOR IMPROVED RADIATION DETECTORS: X-RAY PHOTOEMISSION ANALYSIS  

SciTech Connect

Surface passivation of device-grade radiation detector materials was investigated using x-ray photoelectron spectroscopy in combination with transport property measurements before and after various chemical treatments. Specifically Br-MeOH (2% Br), KOH with NH{sub 4}F/H{sub 2}O{sub 2} and NH{sub 4}OH solutions were used to etch, reduce and oxidize the surface of Cd{sub (1-x)}Zn{sub x}Te semiconductor crystals. Scanning electron microscopy was used to evaluate the resultant microscopic surface morphology. Angle-resolved high-resolution photoemission measurements on the valence band electronic structure and core lines were used to evaluate the surface chemistry of the chemically treated surfaces. Metal overlayers were then deposited on these chemically treated surfaces and the I-V characteristics measured. The measurements were correlated to understand the effect of interface chemistry on the electronic structure at these interfaces with the goal of optimizing the Schottky barrier height for improved radiation detector devices.

Nelson, A; Conway, A; Reinhardt, C; Ferreira, J; Nikolic, R; Payne, S

2007-12-10T23:59:59.000Z

49

Acetylene adsorption on the Si(111)-(7×7) surface: Ultraviolet photoemission and high-resolution electron-energy-loss spectroscopies  

Science Journals Connector (OSTI)

The room temperature adsorption and the thermal reaction of acetylene on the Si(111)-(7×7) surface has been investigated by means of ultraviolet-photoemission spectroscopy and high-resolution electron-energy-loss spectroscopy (HREELS). In the first stage of the adsorption process, the evolution of the restatom- and adatom-related electronic states as a function of acetylene exposure is well described by a modified di-?-bonding model, in which the metallic character of the (7×7) surface plays a fundamental role. For higher exposure, all the restatom dangling bonds are saturated and the adsorption process continues through saturation of the remaining adatoms. In this phase, a molecular tilting is observed, possibly accompanied by a surface atom rearrangement. Upon annealing to 600 °C, acetylene dehydrogenation and partial desorption occur, as demonstrated by the disappearance of the C-H modes in HREELS and the reappearance of the adatom and restatom dangling-bond states in valence-band spectra. At 700 °C the formation of a Si-C compound is observed. Atomic-force-microscopy topographic images taken ex situ after annealing to 800 °C show that the Si-C interface is constituted by islands with lateral dimension of ?300?Å, while the overall surface roughness is 10–20?Å.

V. De Renzi; R. Biagi; U. del Pennino

2001-09-18T23:59:59.000Z

50

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

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

51

High resolution angle-resolved photoemission study of high temperature superconductors: charge-ordering, bilayer splitting and electron-phonon coupling  

E-Print Network (OSTI)

study of high temperature superconductors: charge-ordering,work on high temperature superconductors. These include: (1)interaction in high temperature superconductors. ? 2002

Zhou, Xingjiang; Hussain, Zahid; Shen, Zhi-xun

2003-01-01T23:59:59.000Z

52

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)

spectra of high temperature superconductors – possiblefamilies of high temperature superconductors by using angle-families of high temperature superconductors, identi?ed by a

2006-01-01T23:59:59.000Z

53

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

54

First Observation of Plasmarons in Graphene  

NLE Websites -- All DOE Office Websites (Extended Search)

First Observation of Plasmarons in Graphene Print An international team of scientists performing angle-resolved photoemission spectroscopy (ARPES) experiments at ALS Beamline 7.0.1...

55

Electron-Phonon Coupling in High-Temperature Cuprate Superconductors as Revealed by Angle-resolved Photoemisson Spectroscopy  

E-Print Network (OSTI)

Cuprate oxide high-temperature superconductors are dopedsuperconductivity. High temperature superconductors arein understanding high-temperature superconductors, such as

Zhou, X.J.; Hussain, Z.; Shen, Z.-X.

2005-01-01T23:59:59.000Z

56

Electron-Phonon Coupling in High-Temperature CuprateSuperconductors as Revealed by Angle-resolved PhotoemissonSpectroscopy  

SciTech Connect

We present an application programming interface (API) used to simplify application-level access to both data and semantic range query machinery where both data and search indices are stored and accessed using the HDF5 data model. While the APIs for HDF5 data access and FastBit indexing/query are rather complex, our API simplifies use of these powerful software technologies.

Zhou, X.J.; Hussain, Z.; Shen, Z.-X.

2005-05-01T23:59:59.000Z

57

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

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

58

Si(001) vicinal surface oxidation in O2: Angle-resolved Si 2p core-level study using synchroton radiation  

Science Journals Connector (OSTI)

The aim of this work is to determine if, after oxidation in pure O2, a vicinal surface Si(001) miscut 5° towards the [110] direction, exhibits a preferential SiO2 formation on the [110] ledges. In a first stage, combining XPS (X-ray photoelectron spectroscopy) and LEED (low-energy electron diffraction) available in an auxiliary chamber, we examine the cleaning conditions leading to a non-faceted stepped Si surface with dominant (2 × 1) single domains. This surface preparation is reproduced in the synchroton facility chamber where ARPR-single-resolved photoemission spectroscopy) is performed: after cleaning the Si surface and studying the starting situation (san- states, initial contamination), an ultra-thin oxide film (? 1.5 × 1015 oxidised Si atoms/cm2) is grown at 785–800°C, under Torr of oxygen. The absence of anisotropy in the ARPES emission of the Si 2p core levels taken at the minimum electron escape depth (hv=130eV), points to no extra-growth of the oxide on the ledges. The in-depth distribution of the oxide states seems to be homogeneous, within the sensitivity of the probe. On the other hand, after partial thermal desorption of the ultra-thin oxide film in vacuum, a strong anisotropy in the emission of electrons from SiO2 is seen in areas where oxide patches coexist with bare silicon. It is shown that this ensues from a significant step bunching and (111) faceting of the surface. A correlation is made with SEM (scanning electron microscopy) images of the surface. The problem of step bunching, inasmuch as it can alter the interpretation of shadowing effects, is emphasized.

F. Rochet; H. Roulet; G. Dufour; S. Carniato; C. Guillot; N. Barrett; M. Froment

1992-01-01T23:59:59.000Z

59

Microsoft Word - Photoemission  

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Photoemission Photoemission Resources Available - BE Mid 2012 Mid 2014 Mid 2016 Mid 2017 Beamline X-ray Source Total Total Total Total NSLS 2.5 2.5 0 0 U5UA undulator 1 1 0 0 U13 undulator 1 1 0 0 X1A1* undulator 0.5 0.5 0 0 *ambient pressure APS 0.3 0.3 0.3 0.3 4 ID C undulator 0.3 0.3 0.3 0.3 ALS 3 3 3 3 7.0.1 U5 - undulator 0 0 0 0 Decommissioned summer 2012 10.0.1 U10 - undulator 1 1 1 1 12.0.1 U8 - undulator 0.5 0.5 0.5 0.5 11.0.1.1* EPU5 - undulator 0.5 0.5 0.5 0.5 *PEEM 9.3.2** bend 1 1 1 1 *ambient pressure SSRL 1 1 1 1 BL5-4 undulator 1 1 1 1

60

Correlation of conductivity and angle integrated valence band photoemission  

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Correlation of conductivity and angle integrated valence band photoemission Correlation of conductivity and angle integrated valence band photoemission characteristics in single crystal iron perovskites for 300 K < T < 800 K: Comparison of surface and bulk sensitive methods Title Correlation of conductivity and angle integrated valence band photoemission characteristics in single crystal iron perovskites for 300 K < T < 800 K: Comparison of surface and bulk sensitive methods Publication Type Journal Article Year of Publication 2010 Authors Braun, Artur, Bongjin S. Mun, Yun Sun, Z. Liu, Oliver Gröning, R. Mäder, Selma Erat, Xueyuan Zhang, Samuel S. Mao, Ekaterina Pomjakushina, Kazimierz Conder, and Thomas Graule Journal Journal of Electron Spectroscopy and Related Phenomena Volume 181 Issue 1 Pagination 56-62 Date Published 07/2013

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

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

SciTech Connect

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

62

Metal valence states in Eu0.7NbO3, EuNbO3, and Eu2Nb5O9 by TB-LMTO-ASA band-structure calculations and resonant photoemission spectroscopy  

Science Journals Connector (OSTI)

The electronic structures of Eu2Nb5O9, EuNbO3, and Eu0.7NbO3 have been investigated by photoemission and total-yield spectroscopy with synchrotron radiation, and in the case of Eu2Nb5O9 by tight-binding linear muffin-tin orbital (LMTO) band-structure calculations. A central question for reduced europium niobates is that of the valence of Eu and Nb. Both europium and niobium atoms can appear in different valence states so that various electronic configurations in the title compounds are possible. For this reason, the valence band was studied by the resonant Eu 4d?4f technique to determine the Eu valence. The final-state 4f6 multiplet of divalent Eu is dominant in all spectra. Since there are no 4f density of states at the Fermi level, valence fluctuations are not expected. The niobium valence states were investigated by core-level spectroscopy. We found only one 3d5/23d3/2 doublet for the Nb 3d core level in EuNbO3 and Eu0.7NbO3, while in Eu2Nb5O9, two 3d doublets have been observed, corresponding to two chemically distinct niobium atoms in this compound. The 3d5/2 peak in EuNbO3 is assigned to the +4 nominal valence state at a binding energy of 209.7 eV. The doublet of Eu0.7NbO3 is observed at 0.5 eV higher binding energy (at 210.2 eV), which then corresponds to a nominal Nb+4+? chemical state. In Eu2Nb5O9, the valence of Nb in the NbO6 octahedra is less than +5 and in the Nb6O12 clusters is close to +2 as expected. This is in accordance with the LMTO band-structure calculations.

C. Felser; J. Köhler; A. Simon; O. Jepsen; G. Svensson; S. Cramm; W. Eberhardt

1998-01-15T23:59:59.000Z

63

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.

64

A New Spin on Photoemission Spectroscopy  

E-Print Network (OSTI)

spectra of high temperature superconductors: Possiblecoupling in high- temperature superconductors. Nature 412,ect in a high-transition-temperature superconductor. Nature

Jozwiak, Chris

2010-01-01T23:59:59.000Z

65

A New Spin on Photoemission Spectroscopy  

E-Print Network (OSTI)

the ultra-high vacuum range (UHV) with pressures in the lowAlthough it is easy to write, UHV is not always so easy totemperature and at standard UHV bakeout temperatures (100-

Jozwiak, Chris

2010-01-01T23:59:59.000Z

66

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

SciTech Connect

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

67

Band mapping in x-ray photoelectron spectroscopy: An experimental and theoretical study of W(110) with 1.25 keV excitation  

Science Journals Connector (OSTI)

Angle-resolved photoemission spectroscopy (ARPES) has generally been carried out at energies below ?150 eV, but there is growing interest in going to higher energies so as to achieve greater bulk sensitivity. To this end, we have measured ARPES spectra from a tungsten (110) crystal in a plane containing the [100], [110], and [010] directions with a photon energy of 1253.6 eV. The experimental data are compared to free-electron final-state calculations in an extended zone scheme with no inclusion of matrix elements, as well as highly accurate one-step theory including matrix elements. Both models provide further insight into such future higher-energy ARPES measurements. Special effects occurring in a higher-energy ARPES experiment, such as photon momentum, phonon-induced zone averaging effects, and the degree of cryogenic cooling required are discussed, together with qualitative predictions via appropriate Debye-Waller factors for future experiments with a number of representative elements being presented.

C. Papp; L. Plucinski; J. Minar; J. Braun; H. Ebert; C. M. Schneider; C. S. Fadley

2011-07-18T23:59:59.000Z

68

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

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

69

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

SciTech Connect

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

70

Spectroscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Spectroscopy Spectroscopy Spectroscopy Print In spectroscopy experiments, a sample is illuminated with light and the various product particles (electrons, ions, or fluorescent photons) are detected and analyzed.The unifying feature is that some "property" of a material is measured as the x-ray (photon) energy is swept though a range of values. At the most basic level, one measures the absorption, transmission, or reflectivity of a sample as a function of photon energy. Probes that use the vacuum ultraviolet (VUV) region of the spectrum (10-100 eV) are very well matched to the elucidation of bonding in solids, surfaces, and molecules; to the investigation of electron-electron correlations in solids, atoms, and ions; and to the study of reaction pathways in chemical dynamics. At the lowest end of this energy range (below 1 eV) we have infrared, far-infrared, and terahertz spectroscopies, which are well matched to vibrational modes and other modes of excitation.

71

Spectroscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Spectroscopy Print Spectroscopy Print In spectroscopy experiments, a sample is illuminated with light and the various product particles (electrons, ions, or fluorescent photons) are detected and analyzed.The unifying feature is that some "property" of a material is measured as the x-ray (photon) energy is swept though a range of values. At the most basic level, one measures the absorption, transmission, or reflectivity of a sample as a function of photon energy. Probes that use the vacuum ultraviolet (VUV) region of the spectrum (10-100 eV) are very well matched to the elucidation of bonding in solids, surfaces, and molecules; to the investigation of electron-electron correlations in solids, atoms, and ions; and to the study of reaction pathways in chemical dynamics. At the lowest end of this energy range (below 1 eV) we have infrared, far-infrared, and terahertz spectroscopies, which are well matched to vibrational modes and other modes of excitation.

72

Spectroscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Spectroscopy Print Spectroscopy Print In spectroscopy experiments, a sample is illuminated with light and the various product particles (electrons, ions, or fluorescent photons) are detected and analyzed.The unifying feature is that some "property" of a material is measured as the x-ray (photon) energy is swept though a range of values. At the most basic level, one measures the absorption, transmission, or reflectivity of a sample as a function of photon energy. Probes that use the vacuum ultraviolet (VUV) region of the spectrum (10-100 eV) are very well matched to the elucidation of bonding in solids, surfaces, and molecules; to the investigation of electron-electron correlations in solids, atoms, and ions; and to the study of reaction pathways in chemical dynamics. At the lowest end of this energy range (below 1 eV) we have infrared, far-infrared, and terahertz spectroscopies, which are well matched to vibrational modes and other modes of excitation.

73

Linear dichroism and resonant photoemission in Gd 011  

SciTech Connect

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

74

Full Hemisphere Fermi Surface Mapping Using A Novel Toroidal Electron Spectrometer  

SciTech Connect

An overview is provided of a next-generation toroidal angle-resolving photoemission spectrometer, currently in operation at BESSY II. The instrument features exceptional multi-detection in energy and angle, facilitating rapid full-hemisphere photoemission measurements. The instrument is ideal for band structure and Fermi Surface (FS) mapping using Angle Resolved Photoemission Spectroscopy (ARPES). Recent full-hemisphere FS measurements of a prototypical material, copper, reveal previously unseen fine structure due to lifetime broadening, demonstrating the high angular resolution and dense {kappa}-space sampling capabilities of the instrument.

Tadich, A. [Australian Synchrotron, Clayton, VIC 3168 (Australia); Department of Physics, La Trobe University, Bundoora, VIC 3086 (Australia); Riley, J.; Huwald, E.; Leckey, R. [Department of Physics, La Trobe University, Bundoora, VIC 3086 (Australia); Seyller, T.; Ley, L. [Institut fuer Technische Physik II, Universitaet Erlangen Nurnberg, 91058 Erlangen (Germany)

2010-06-23T23:59:59.000Z

75

Pt–metal oxide aerogel catalysts: X-ray photoemission investigation  

Science Journals Connector (OSTI)

X-ray photoemission spectroscopy was used to study Pt–metal oxide aerogel catalysts that have been developed to respond to increased NO x emissions of lean-burn engines. Lean-burn engines critical components of low and zero emission vehicles produce much higher levels of engine-out NO x and current three-way catalytic converters are not sufficient to meet Clean Air Act standards. Platinum catalysts were formed by the reaction of modified Pt coordination compounds with selected transition–metal alkoxides through sol–gel techniques into aerogels. Photoemission measurements of the Pt 4f Si 2p Ti 2p O 1s and C 1s core lines were used to evaluate the chemistry of the material after each processing step. Results indicate Pt–O bonding and reduced Pt disbursed in the aerogel. In addition Si 2p Ti 2p and O 1s binding energies indicate an oxo-bridged network structure.

A. J. Nelson; John G. Reynolds; R. D. Sanner; P. R. Coronado; L. M. Hair

2001-01-01T23:59:59.000Z

76

Raising Photoemission Efficiency with Surface Acoustic Waves  

SciTech Connect

We are developing a novel technique that may help increase the efficiency and reduce costs of photoelectron sources used at electron accelerators. The technique is based on the use of Surface Acoustic Waves (SAW) in piezoelectric materials, such as GaAs, that are commonly used as photocathodes. Piezoelectric fields produced by the traveling SAW spatially separate electrons and holes, reducing their probability of recombination, thereby enhancing the photoemission quantum efficiency of the photocathode. Additional advantages could be increased polarization provided by the enhanced mobility of charge carriers that can be controlled by the SAW and the ionization of optically-generated excitons resulting in the creation of additional electron-hole pairs. It is expected that these novel features will reduce the cost of accelerator operation. A theoretical model for photoemission in the presence of SAW has been developed, and experimental tests of the technique are underway.

A. Afanasev, F. Hassani, C.E. Korman, V.G. Dudnikov, R.P. Johnson, M. Poelker, K.E.L. Surles-Law

2012-07-01T23:59:59.000Z

77

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

78

Photoemission study of Si(111)-Ge(5×5) surfaces  

Science Journals Connector (OSTI)

Photoemission spectroscopy was used to study Si(111)-Ge(5×5) surfaces prepared by annealing Ge films deposited onto Si(111)-(7×7) substrates. The Si 2p core-level line shape was modified in going from (7×7) to (5×5) systems. By decomposing the spectra into bulk- and surface-shifted components the changes in line shape were identified as due to selective replacement of Si by Ge in different layers of the substrate, without any drastic change in the surface structure. The Ge 3d core-level line shape for the Si(111)-Ge(5×5) surface was also measured and compared with that for the Ge(111)-c(2×8) surface. These results are discussed in terms of models for the Si(111)-(7×7) structure. A surface state was observed on the Si(111)-Ge(5×5) surface, which gave rise to a metalliclike Fermi edge in the angle-integrated spectra; a similar surface state was observed on the Si(111)-(7×7) surface but not on the Ge(111)-c(2×8) surface.

T. Miller; T. C. Hsieh; T. -C. Chiang

1986-05-15T23:59:59.000Z

79

n-type doping in Cd2SnO4: A study by EELS and photoemission  

Science Journals Connector (OSTI)

The influence of n-type doping on the electronic structure of Cd2SnO4 has been studied by electron-energy-loss spectroscopy (EELS) and UV photoemission spectroscopy (UPS). In substitution on Cd sites or Sb substitution in Sn sites leads to the the appearance of well-defined plasmon loss peaks in EELS, with a maximum plasmon energy of just below 0.6 eV in Sb-doped material. A weak conduction-band feature is observed in UPS, the width of which is of the order expected from a simple free-electron model. © 1996 The American Physical Society.

Y. Dou and R. G. Egdell

1996-06-15T23:59:59.000Z

80

4f-derived photoemission and 4f-ligand hybridization in light rare-earth halides  

Science Journals Connector (OSTI)

We have studied the 4f-derived photoemission spectra of insulating Ce, Pr, and Nd trihalides by resonant photoemission spectroscopy. A double-peak structure is observed in every f spectrum as in metallic Ce, Pr, and Nd compounds and is successfully analyzed in terms of the cluster model. This confirms that the two peaks arise from hybridization between the 4f and ligand p orbitals rather than from two different screening channels of the f hole. The f-ligand hybridization strength is found to decrease on going from the Ce to Pr to Nd compounds, but appears to remain significantly large for heavier rare earths, suggesting the importance of hybridization effects in heavy rare-earth compounds.

A. Fujimori; T. Miyahara; T. Koide; T. Shidara; H. Kato; H. Fukutani; S. Sato

1988-10-15T23:59:59.000Z

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.


81

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

NLE Websites -- All DOE Office Websites (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...

82

Spectroscopic imaging, diffraction, and holography with x-ray photoemission  

SciTech Connect

X-ray probes are capable of determining the spatial structure of an atom in a specific chemical state, over length scales from about a micron all the way down to atomic resolution. Examples of these probes include photoemission microscopy, energy-dependent photoemission diffraction, photoelectron holography, and X-ray absorption microspectroscopy. Although the method of image formation, chemical-state sensitivity, and length scales can be very different, these X-ray techniques share a common goal of combining a capability for structure determination with chemical-state specificity. This workshop will address recent advances in holographic, diffraction, and direct imaging techniques using X-ray photoemission on both theoretical and experimental fronts. A particular emphasis will be on novel structure determinations with atomic resolution using photoelectrons.

Not Available

1992-02-01T23:59:59.000Z

83

Photoemission and the Electronic Structure of PuCoGa5  

Science Journals Connector (OSTI)

The electronic structure of the first Pu-based superconductor PuCoGa5 is explored using photoelectron spectroscopy and a novel theoretical scheme. Exceptional agreement between calculation and experiment defines a path forward for understanding the electronic structure aspects of Pu-based materials. The photoemission results show two separate regions of 5f electron spectral intensity, one at the Fermi energy and another centered 1.2 eV below the Fermi level. The results for PuCoGa5 clearly indicate 5f electron behavior on the threshold between localized and itinerant. Comparisons to delta phase Pu metal show a broader framework for understanding the fundamental electronic properties of the Pu 5f levels in general within two configurations, one localized and one itinerant.

J. J. Joyce, J. M. Wills, T. Durakiewicz, M. T. Butterfield, E. Guziewicz, J. L. Sarrao, L. A. Morales, A. J. Arko, and O. Eriksson

2003-10-22T23:59:59.000Z

84

SSRL HEADLINES Jul 2001  

NLE Websites -- All DOE Office Websites (Extended Search)

1 Jul, 2001 1 Jul, 2001 _____________________________________________________________________________ Contents of This Issue: Science Highlight - Complex Materials Research by Angle-Resolved Photoemission Spectroscopy: Challenging the Mystery of the High Tc Superconductivity 2000-2001 Experimental Run Highlights Stanford-Berkeley 2001 SR Summer School: A Successful Start to the First in a Series SSRL Well Represented at the American Crystallographic Association Meeting The Shutdown Clock is Ticking BL10 Insertion Device Repair on Track for November User Operations Semi-annual SPEAR3 Lehman Review SSRL's 28th Annual Users' Meeting is Coming Soon! User Research Administration Announcements Job Opportunities at SSRL 1. Science Highlight - Complex Materials Research by Angle-Resolved

85

Technique Subgroupings Spectroscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

and NSLS-II beamlines according to DOE Technique Scheme and NSLS-II beamlines according to DOE Technique Scheme Technique Subgroupings Spectroscopy 01 - Low Energy Spectroscopy Infrared Photoemission U12IR, U4IR / MET* U5UA, U13 / ESM 02 - Soft X-Ray Spectroscopy Soft X-ray Spectroscopy Tender XAS U4B, U7A, X24A / SST, SSS* X15B, X19A / TES* 03 - Hard X-ray Spectroscopy EXAFS X3A, X3B, X11A, X11B, X18A, X18B, X23A2 / ISS, BMM, QAS*, XAS* 04 - Optics/Calibration/Metrology U3C,X8A/ OFT,MID Scattering 05 X-ray Diffraction X-Ray Powder Diffraction Extreme Conditions Energy Dispersive Micro-Beam Diffraction X7B,X10B,X14A,X16C,X17A / XPD,IXD* X17B2,X17B3,X17C / XPD, TEC*, 4DE* X17B1, X17B2 / NA X13B / MXD* 06 MX, footprinting Protein Crystallography X-ray footprinting X4A, X4C, X6A, X12B, X12C, X25, X29 / FMX, AMX, NYX;

86

Photoemission from Ar, Kr, and Xe on Pb(111)  

Science Journals Connector (OSTI)

Angle-resolved photoelectron spectra were measured for the valence p states of Ar, Kr, and Xe on Pb(111). The thickness of the rare-gas layers was varied between 0.05 and about 5 monolayers. For each layer the work function was deduced from the width of the photoelectron energy-distribution curve. On Pb(111) tightly packed monolayers were prepared, exhibiting energy dispersion of the valence p states, which is discussed in the framework of the known two-dimensional band structure. The spectral features are very sharp, as can be seen from the full width at half maximum value of 175 meV for the Xe 5p1/2 peak. For Xe the submonolayer regime was also studied, where single atoms are adsorbed together with small three-dimensional clusters. The single atoms exhibit no dispersion and no split of the p3/2 level into two sublevels. This demonstrates that these features are derived from lateral interaction in the rare-gas monolayer. On top of the monolayer a second completely filled layer can be prepared for Ar, Kr, and Xe. The second-layer shift in binding energy is 720 meV for Ar and Kr and 525 meV for Xe. It is about 6 times as large as the work-function changes induced by the monolayer. This observation can only be explained in the known final-state interpretation of the layer-dependent shifts in binding energy.

K. Jacobi

1988-09-15T23:59:59.000Z

87

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

SciTech Connect

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

88

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

89

Photoemission currentspacecraft voltage relation: Key to routine, quantitative low-energy plasma measurements  

E-Print Network (OSTI)

Photoemission current�spacecraft voltage relation: Key to routine, quantitative low-energy plasma measurements J. D. Scudder and Xuejun Cao Department of Physics and Astronomy, University of Iowa, Iowa City F/C. The photoemission current function is found to be time independent using nearly 10 months of GGS-Polar data from

California at Berkeley, University of

90

Operating experience with a GaAs photoemission electron source  

SciTech Connect

We report on the development of several operating procedures that promise to make GaAs photoemission electron sources easier to construct, more reliable to operate, and more amenable to use in dynamic vacuum systems. We describe in particular a method for ''ohmically'' heating a <100> crystal of GaAs under vacuum to approximately 600 /sup 0/C. We also discuss our observations of the role of oxygen in the activation of the crystal surface, the use of continuous cesiation, and of the performance of the crystal under varying vacuum conditions.

Tang, F.C.; Lubell, M.S.; Rubin, K.; Vasilakis, A.; Eminyan, M.; Slevin, J.

1986-12-01T23:59:59.000Z

91

Beamline 4.0.3  

NLE Websites -- All DOE Office Websites (Extended Search)

3 Print 3 Print High-resolution spectroscopy of complex materials (MERLIN) Endstations: MERIXS: High-resolution inelastic scattering ARPES: Angle-resolved photoemission spectroscopy GENERAL BEAMLINE INFORMATION Operational 2011 Source characteristics 9.0-cm-period quasiperiodic elliptical polarization undulator (EPU9) Energy range 9eV-120eV with current gratings Monochromator Variable-included-angle spherical grating monochromator (SGM) Calculated flux (1.9 GeV, 400 mA) 1012 photons/s/0.01%BW at 100 eV Resolving power (E/ΔE) High flux 1200 lines/mm; ~1/25,000 Endstations High-resolution inelastic scattering (MERIXS) and ARPES Characteristics Milli-Electron-volt Resolution beamLINe (MERLIN): Ultrahigh-resolution inelastic scattering and angle-resolved photoemission

92

Beamline 4.0.3  

NLE Websites -- All DOE Office Websites (Extended Search)

3 Print 3 Print High-resolution spectroscopy of complex materials (MERLIN) Endstations: MERIXS: High-resolution inelastic scattering ARPES: Angle-resolved photoemission spectroscopy GENERAL BEAMLINE INFORMATION Operational 2011 Source characteristics 9.0-cm-period quasiperiodic elliptical polarization undulator (EPU9) Energy range 9eV-120eV with current gratings Monochromator Variable-included-angle spherical grating monochromator (SGM) Calculated flux (1.9 GeV, 400 mA) 1012 photons/s/0.01%BW at 100 eV Resolving power (E/ΔE) High flux 1200 lines/mm; ~1/25,000 Endstations High-resolution inelastic scattering (MERIXS) and ARPES Characteristics Milli-Electron-volt Resolution beamLINe (MERLIN): Ultrahigh-resolution inelastic scattering and angle-resolved photoemission

93

Beamline 4.0.3  

NLE Websites -- All DOE Office Websites (Extended Search)

3 Print 3 Print High-resolution spectroscopy of complex materials (MERLIN) Endstations: MERIXS: High-resolution inelastic scattering ARPES: Angle-resolved photoemission spectroscopy GENERAL BEAMLINE INFORMATION Operational 2011 Source characteristics 9.0-cm-period quasiperiodic elliptical polarization undulator (EPU9) Energy range 9eV-120eV with current gratings Monochromator Variable-included-angle spherical grating monochromator (SGM) Calculated flux (1.9 GeV, 400 mA) 1012 photons/s/0.01%BW at 100 eV Resolving power (E/ΔE) High flux 1200 lines/mm; ~1/25,000 Endstations High-resolution inelastic scattering (MERIXS) and ARPES Characteristics Milli-Electron-volt Resolution beamLINe (MERLIN): Ultrahigh-resolution inelastic scattering and angle-resolved photoemission

94

Beamline 4.0.3  

NLE Websites -- All DOE Office Websites (Extended Search)

3 Print 3 Print High-resolution spectroscopy of complex materials (MERLIN) Endstations: MERIXS: High-resolution inelastic scattering ARPES: Angle-resolved photoemission spectroscopy GENERAL BEAMLINE INFORMATION Operational 2011 Source characteristics 9.0-cm-period quasiperiodic elliptical polarization undulator (EPU9) Energy range 9eV-120eV with current gratings Monochromator Variable-included-angle spherical grating monochromator (SGM) Calculated flux (1.9 GeV, 400 mA) 1012 photons/s/0.01%BW at 100 eV Resolving power (E/ΔE) High flux 1200 lines/mm; ~1/25,000 Endstations High-resolution inelastic scattering (MERIXS) and ARPES Characteristics Milli-Electron-volt Resolution beamLINe (MERLIN): Ultrahigh-resolution inelastic scattering and angle-resolved photoemission

95

Beamline 4.0.3  

NLE Websites -- All DOE Office Websites (Extended Search)

3 Print 3 Print High-resolution spectroscopy of complex materials (MERLIN) Endstations: MERIXS: High-resolution inelastic scattering ARPES: Angle-resolved photoemission spectroscopy GENERAL BEAMLINE INFORMATION Operational 2011 Source characteristics 9.0-cm-period quasiperiodic elliptical polarization undulator (EPU9) Energy range 9eV-120eV with current gratings Monochromator Variable-included-angle spherical grating monochromator (SGM) Calculated flux (1.9 GeV, 400 mA) 1012 photons/s/0.01%BW at 100 eV Resolving power (E/ΔE) High flux 1200 lines/mm; ~1/25,000 Endstations High-resolution inelastic scattering (MERIXS) and ARPES Characteristics Milli-Electron-volt Resolution beamLINe (MERLIN): Ultrahigh-resolution inelastic scattering and angle-resolved photoemission

96

Beamline 4.0.3  

NLE Websites -- All DOE Office Websites (Extended Search)

3 Print 3 Print High-resolution spectroscopy of complex materials (MERLIN) Endstations: MERIXS: High-resolution inelastic scattering ARPES: Angle-resolved photoemission spectroscopy GENERAL BEAMLINE INFORMATION Operational 2011 Source characteristics 9.0-cm-period quasiperiodic elliptical polarization undulator (EPU9) Energy range 9eV-120eV with current gratings Monochromator Variable-included-angle spherical grating monochromator (SGM) Calculated flux (1.9 GeV, 400 mA) 1012 photons/s/0.01%BW at 100 eV Resolving power (E/ΔE) High flux 1200 lines/mm; ~1/25,000 Endstations High-resolution inelastic scattering (MERIXS) and ARPES Characteristics Milli-Electron-volt Resolution beamLINe (MERLIN): Ultrahigh-resolution inelastic scattering and angle-resolved photoemission

97

Beamline 4.0.3  

NLE Websites -- All DOE Office Websites (Extended Search)

3 Print 3 Print High-resolution spectroscopy of complex materials (MERLIN) Endstations: MERIXS: High-resolution inelastic scattering ARPES: Angle-resolved photoemission spectroscopy GENERAL BEAMLINE INFORMATION Operational 2011 Source characteristics 9.0-cm-period quasiperiodic elliptical polarization undulator (EPU9) Energy range 9eV-120eV with current gratings Monochromator Variable-included-angle spherical grating monochromator (SGM) Calculated flux (1.9 GeV, 400 mA) 1012 photons/s/0.01%BW at 100 eV Resolving power (E/ΔE) High flux 1200 lines/mm; ~1/25,000 Endstations High-resolution inelastic scattering (MERIXS) and ARPES Characteristics Milli-Electron-volt Resolution beamLINe (MERLIN): Ultrahigh-resolution inelastic scattering and angle-resolved photoemission

98

Beamline 4.0.3  

NLE Websites -- All DOE Office Websites (Extended Search)

3 Print 3 Print High-resolution spectroscopy of complex materials (MERLIN) Endstations: MERIXS: High-resolution inelastic scattering ARPES: Angle-resolved photoemission spectroscopy GENERAL BEAMLINE INFORMATION Operational 2011 Source characteristics 9.0-cm-period quasiperiodic elliptical polarization undulator (EPU9) Energy range 9eV-120eV with current gratings Monochromator Variable-included-angle spherical grating monochromator (SGM) Calculated flux (1.9 GeV, 400 mA) 1012 photons/s/0.01%BW at 100 eV Resolving power (E/ΔE) High flux 1200 lines/mm; ~1/25,000 Endstations High-resolution inelastic scattering (MERIXS) and ARPES Characteristics Milli-Electron-volt Resolution beamLINe (MERLIN): Ultrahigh-resolution inelastic scattering and angle-resolved photoemission

99

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

SciTech Connect

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

100

Fully relativistic surface green function and its application to surface spectroscopies  

SciTech Connect

A fully relativistic layer-KKR formalism was developed and implemented for calculating the single-particle Green function in atomic layers parallel to crystalline surfaces magnetic and non magnetic materials: The method was applied to the calculation surface spectroscopies, such as low energy electron diffraction (LEED), angle-resolve ultraviolet photo emission spectroscopy (UPS), and photoelectron scattering. Numeric tests were performed for non magnetic actinide surfaces and magnetic Fe surface Theoretical angle-resolved UPS spectra are presented for uranium monolayers on Pt(111) and for f.c.c. u(lll) surfaces. We find that u island formation can take place if a peak in the UPS spectra appears just before the Fermi energy immediately as u is deposited on P and we suggest an experimental procedure for testing this prediction. An intensity map photo excited electrons from the 2p{sub 3/2} core states of Fe(110) surface is also show Sizable magnetic anisotropy is found due to the interference between exchange and spin-orbit interaction, which is suitable for studying a possible surface-induced magnetism actinide adlayers.

Tamura, E. [Seaborg (Glenn T.) Inst. for Transactinium Science, Livermore, CA (United States)

1993-06-30T23:59:59.000Z

Note: This page contains sample records for the topic "angle-resolved photoemission spectroscopy" from the National Library of EnergyBeta (NLEBeta).
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101

Beamline 12.0.1  

NLE Websites -- All DOE Office Websites (Extended Search)

Detectors Scienta SES-100 (angle-resolved photoemission), R3000, R4000 Sample format UHV-compatible solids Sample preparation Sample manipulator with five degrees of freedom;...

102

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

SciTech Connect

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

103

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

SciTech Connect

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

104

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

SciTech Connect

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

105

A new scanning photoemission microscope for ELETTRA: SuperMAXIMUM  

Science Journals Connector (OSTI)

High brightness third?generation synchrotrons allow diffraction?limited performance and large flux for scanning photoemission microscopes. A new microscope SuperMAXIMUM is being developed at the University of Wisconsin Center for X ray Lithography in collaboration with the Sincrotrone Trieste. The beamline being built in Trieste uses a variable angle spherical gratingmonochromator (VASGM). A combination of rotation of a plane mirror and rotation of the spherical grating keeps the slit positions and beam directions fixed. The microscope objectives are normal?incidence multilayer?coated Schwarzschild objectives. The project which is nearing completion utilizes novel designs for optics alignment sample rastering mechanics and software control. We will discuss the project status new designs and techniques.

John T. Welnak; H. Solak; J. Wallace; F. Cerrina; F. Barbo; M. Bertolo; A. Bianco; S. Di Fonzo; S. Fontana; W. Jark; F. Mazzolini; R. Rosei; A. Savoia; J.H. Underwood; G. Margaritondo

1996-01-01T23:59:59.000Z

106

A new scanning photoemission microscope for ELETTRA: SuperMAXIMUM  

SciTech Connect

High brightness, third-generation synchrotrons allow diffraction-limited performance and large flux for scanning photoemission microscopes. A new microscope, SuperMAXIMUM, is being developed at the University of Wisconsin Center for X ray Lithography in collaboration with the Sincrotrone Trieste. The beamline, being built in Trieste, uses a variable angle spherical grating monochromator (VASGM). A combination of rotation of a plane mirror and rotation of the spherical grating keeps the slit positions and beam directions fixed. The microscope objectives are normal-incidence, multilayer-coated Schwarzschild objectives. The project, which is nearing completion, utilizes novel designs for optics alignment, sample rastering mechanics, and software control. We will discuss the project status, new designs, and techniques. {copyright} {ital 1996 American Institute of Physics.}

Welnak, J.T.; Solak, H.; Wallace, J.; Cerrina, F.; Barbo, F.; Bertolo, M.; Bianco, A.; Di Fonzo, S.; Fontana, S.; Jark, W.; Mazzolini, F.; Rosei, R.; Savoia, A.; Underwood, J.; Margaritondo, G. [University of WI--Center for X ray Lithography, 3731 Schneider Drive, Stoughton, WI 53589 (United States)] [University of WI--Center for X ray Lithography, 3731 Schneider Drive, Stoughton, WI 53589 (United States); [Sincrotrone Trieste, Padriciano 99, 34012, Trieste (Italy); [Lawrence Berkeley Laboratory, Center for X ray Optics, 1 Cyclotron Road, 80-101, Berkeley, CA 94720 (United States); [Institut de Physique Appliqee, Ecole Polytechnique Federale, CH-1015, Lausanne (Switzerland)

1996-09-01T23:59:59.000Z

107

Nonlinear Photoemission Electron Micrographs of Plasmonic Nanoholes in Gold Thin Films  

SciTech Connect

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

108

Favorable electronic structure for organic solar cells induced by strong interaction at interface  

SciTech Connect

To clarify the role of buffer layer in organic solar cells (OSCs), the electronic properties of bathocuproine (BCP)/Mg interface were systematically investigated by using ultraviolet photoemissions spectroscopy, high-resolution X-ray photoemission spectroscopy, angle-resolved X-ray photoemission spectroscopy and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. The results show there are gap states at the interface, which are caused by the interaction between BCP and Mg. The formation of Mg-N bond was found at the interface. The NEXAFS measurements show that BCP molecules for 1-2 monolayers are lying-down on the substrate, whereas orient randomly for thick BCP layer. It was supposed that the gap states and the highly-ordered orientation of thin BCP layer are the reasons for improving the performance of OSC with BCP buffer layer and low work function metal cathode.

Wang, Shenghao, E-mail: wsh8511@gmail.com; Hao, Xia; Fu, Wei; Akimoto, Katsuhiro [Institute of Applied Physics, University of Tsukuba, Tsukuba, Ibaraki 305-8573 (Japan); Sakurai, Takeaki [Institute of Applied Physics, University of Tsukuba, Tsukuba, Ibaraki 305-8573 (Japan); PRESTO, Japan Science and Technology Agency (JST), Kawaguchi, Saitama 332-0012 (Japan); Masuda, Shigeru [Department of Basic Science, Graduate School of Arts and Sciences, The University of Tokyo, Komaba, Meguro, Tokyo 153-8902 (Japan)

2013-11-14T23:59:59.000Z

109

Dynamic final-state nanoparticle-substrate interaction in the photoemission of dodecanethiolate-passivated Ag nanoparticles on graphite substrates  

Science Journals Connector (OSTI)

We have carried out a photoemission study of dodecanethiolate- (DT-) passivated Ag nanoparticles supported on the highly oriented pyrolytic graphite (HOPG) substrates. From detailed photoemission measurements, it is found that the Fermi-level onsets in the photoemission spectra of DT-passivated Ag nanoparticles on the HOPG substrates are not the metallic Fermi edge, with the steep slope being away from the Fermi level. We attribute the unusual spectral features in the vicinity of Fermi level to the dynamic final-state effect in photoemission, indicative of the interaction between the nanoparticle and substrate through the surface passivants on a femtosecond time scale.

Akinori Tanaka; Yuitsu Takeda; Tazumi Nagasawa; Shigeru Sato

2003-01-17T23:59:59.000Z

110

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

111

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

112

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

SciTech Connect

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

113

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

SciTech Connect

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

114

Core-level photoemission of the Si(1 1 1) surface using synchrotron radiation  

E-Print Network (OSTI)

-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan c Synchrotron Radiation Laboratory, The Institute of Solid StateCore-level photoemission of the Si(1 1 1)± 21 p � 21 p -Ag surface using synchrotron radiation, Wako-shi, Saitama 351-0198, Japan b Department of Physics, School of Science, University of Tokyo, 7

Hasegawa, Shuji

115

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-conversion

Atwater, Harry

116

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

SciTech Connect

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

117

High-resolution core-level photoemission study of Eu-induced (3×2)?(3×4) reconstruction on Ge(111)  

Science Journals Connector (OSTI)

We have investigated Eu-induced Ge(111)-(3×2)?(3×4) reconstruction by high-resolution core-level photoelectron spectroscopy using synchrotron radiation and low-energy electron diffraction. Recent scanning tunneling microscopy (STM) observations [Phys. Rev. B 73, 125332 (2006)] revealed that the Ge arrangement of this reconstruction can be well described in terms of the honeycomb chain-channel (HCC) geometry proposed earlier for metal/Si(111)-(3×1) and -(3×2) surfaces; the Eu atoms, however, were found to reside at two different adsorption sites in the Eu?Ge(111)-(3×2)?(3×4) reconstruction, in contrast to the equivalent adsorption sites (e.g., T4) occupied in the case of Si. The present photoemission results provide further information about the atomic arrangement of Eu?Ge(111)-(3×2)?(3×4). In particular, we show that the Ge 3d core-level data cannot be interpreted by the HCC structure with the Eu atoms adsorbed only on T4 sites, giving a spectroscopic support for the suggestions based on the earlier STM data. We consider here a modified HCC-based configuration for the Eu?Ge(111)-(3×2)?(3×4) surface where the Eu atoms occupy two different sites in the empty channel between the neighboring Ge honeycomb chains. The atomic models are discussed in the context of the Ge 3d and Eu 4f data as well as the previous results available in the literature. Finally, we propose a structural model that allows us to account for the present photoemission and earlier STM findings.

M. Kuzmin; R. E. Perälä; P. Laukkanen; M. Ahola-Tuomi; I. J. Väyrynen

2006-09-22T23:59:59.000Z

118

Vibrationally resolved photoelectron-spin-polarization spectroscopy of HI molecules  

Science Journals Connector (OSTI)

The photoemission from HI is studied separately for different vibrational levels of the ?2 final ionic states using spin-resolved photoelectron spectroscopy with circularly polarized light. Constant-ionic-state measurements of the cross sections ? and the polarization parameters A indicate that all channels are strongly influenced by autoionization resonances. By combining these data, sums of partial contributions to ? are analyzed in detail to obtain specific information on the coupling of the resonances to the outgoing partial waves ??. Apart from generally similar trends, the results show pronounced variations for different vibrational levels.

N. Böwering; M. Salzmann; M. Müller; H.-W. Klausing; U. Heinzmann

1992-01-01T23:59:59.000Z

119

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

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

120

Interrelation between the Pseudogap and the Incoherent Quasiparticle Features of High- Tc Superconductors  

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Using a scenario of a hybridized mixture of localized bipolarons and conduction electrons we demonstrate for the latter the simultaneous appearance of a pseudogap and of strong incoherent contributions to their quasiparticle spectrum which arise from phonon shakeoff effects. This can be traced back to temporarily fluctuating local lattice deformations, giving rise to a double-peak structure in the pair distribution function, which should be a key feature in testing the origin of these incoherent contributions, recently seen in angle resolved photoemission spectroscopy.

J. Ranninger and A. Romano

1998-06-22T23:59:59.000Z

Note: This page contains sample records for the topic "angle-resolved photoemission spectroscopy" from the National Library of EnergyBeta (NLEBeta).
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to obtain the most current and comprehensive results.


121

Electronic band structure imaging of three layer twisted graphene on single crystal Cu(111)  

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Few layer graphene (FLG) is grown on single crystal Cu(111) by Chemical Vapor Deposition, and the electronic valence band structure is imaged by Angle-Resolved Photo-Emission Spectroscopy. It is found that graphene essentially grows polycrystalline. Three nearly ideal Dirac cones are observed along the Cu ?{sup ¯}K{sup ¯} direction in k-space, attributed to the presence of ?4° twisted three layer graphene with negligible interlayer coupling. The number of layers and the stacking order are compatible with Raman data analysis demonstrating the complementarity of the two techniques for a more accurate characterization of FLG.

Marquez Velasco, J. [National Center for Scientific Research “Demokritos,” 15310 Athens (Greece) [National Center for Scientific Research “Demokritos,” 15310 Athens (Greece); Department of Physics, National Technical University of Athens, Athens (Greece); Kelaidis, N.; Xenogiannopoulou, E.; Tsoutsou, D.; Tsipas, P.; Speliotis, Th.; Pilatos, G.; Likodimos, V.; Falaras, P.; Dimoulas, A., E-mail: dimoulas@ims.demokritos.gr [National Center for Scientific Research “Demokritos,” 15310 Athens (Greece); Raptis, Y. S. [Department of Physics, National Technical University of Athens, Athens (Greece)] [Department of Physics, National Technical University of Athens, Athens (Greece)

2013-11-18T23:59:59.000Z

122

Nearly Perfect Fluidity in a High Temperature Superconductor  

E-Print Network (OSTI)

Perfect fluids are characterized as having the smallest ratio of shear viscosity to entropy density, {\\eta}/s, consistent with quantum uncertainty and causality. So far, nearly perfect fluids have only been observed in the Quark-Gluon Plasma (QGP) and in unitary atomic Fermi gases (UFG), exotic systems that are amongst the hottest and coldest objects in the known universe, respectively. We use Angle Resolve Photoemission Spectroscopy (ARPES) to measure the temperature dependence of an electronic analogue of {\\eta}/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.

J. D. Rameau; T. J. Reber; H. -B. Yang; S. Akhanjee; G. D. Gu; S. Campbell; P. D. Johnson

2014-09-19T23:59:59.000Z

123

Nearly Perfect Fluidity in a High Temperature Superconductor  

E-Print Network (OSTI)

Perfect fluids are characterized as having the smallest ratio of shear viscosity to entropy density, {\\eta}/s, consistent with quantum uncertainty and causality. So far, nearly perfect fluids have only been observed in the Quark-Gluon Plasma (QGP) and in unitary atomic Fermi gases (UFG), exotic systems that are amongst the hottest and coldest objects in the known universe, respectively. We use Angle Resolve Photoemission Spectroscopy (ARPES) to measure the temperature dependence of an electronic analogue of {\\eta}/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; Yang, H -B; Akhanjee, S; Gu, G D; Campbell, S; Johnson, P D

2014-01-01T23:59:59.000Z

124

Nearly perfect fluidity in a high-temperature superconductor  

Science Journals Connector (OSTI)

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.

J. D. Rameau; T. J. Reber; H.-B. Yang; S. Akhanjee; G. D. Gu; P. D. Johnson; S. Campbell

2014-10-13T23:59:59.000Z

125

EMSL - spectroscopy  

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

126

Impact of Mg concentration on energy-band-depth profile of Mg-doped InN epilayers analyzed by hard X-ray photoelectron spectroscopy  

SciTech Connect

The electronic structures of Mg-doped InN (Mg-InN) epilayers with the Mg concentration, [Mg], ranging from 1 × 10{sup 19} to 5 × 10{sup 19} cm{sup ?3} were systematically investigated by soft and hard X-ray photoelectron spectroscopies. The angle-resolved results on the core-level and valence band photoelectron spectra as a function of [Mg] revealed that the energy band of Mg-InN showed downward bending due to the n{sup +} surface electron accumulation and p type layers formed in the bulk. With an increase in [Mg], the energy-band changed from monotonic to two-step n{sup +}p homojunction structures. The oxygen concentration rapidly increased at the middle-bulk region (?4.5 to ?7.5 nm) from the surface, which was one of the reasons of the transformation of two-step energy band.

Imura, M.; Tsuda, S.; Nagata, T.; Takeda, H.; Liao, M. Y.; Koide, Y. [National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan)] [National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Yang, A. L.; Yamashita, Y.; Yoshikawa, H.; Kobayashi, K. [NIMS/SPring-8, NIMS, 1-1-1 Koto, Sayo-cho, Sayo, Hyogo 679-5148 (Japan)] [NIMS/SPring-8, NIMS, 1-1-1 Koto, Sayo-cho, Sayo, Hyogo 679-5148 (Japan); Yamaguchi, T. [Faculty of Engineering, Kogakuin University, 2665-1 Nakano-machi, Hachiouji, Tokyo 192-0015 (Japan) [Faculty of Engineering, Kogakuin University, 2665-1 Nakano-machi, Hachiouji, Tokyo 192-0015 (Japan); Faculty of Science and Engineering, Ritsumeikan University, 1-1-1 Noji-Higashi, Kusatsu 525-8577 (Japan); Kaneko, M.; Uematsu, N.; Wang, K.; Araki, T. [Faculty of Science and Engineering, Ritsumeikan University, 1-1-1 Noji-Higashi, Kusatsu 525-8577 (Japan)] [Faculty of Science and Engineering, Ritsumeikan University, 1-1-1 Noji-Higashi, Kusatsu 525-8577 (Japan); Nanishi, Y. [Faculty of Science and Engineering, Ritsumeikan University, 1-1-1 Noji-Higashi, Kusatsu 525-8577 (Japan) [Faculty of Science and Engineering, Ritsumeikan University, 1-1-1 Noji-Higashi, Kusatsu 525-8577 (Japan); Faculty of Materials Science and Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of)

2013-10-14T23:59:59.000Z

127

Photo-emission rate of sQGP at finite density  

E-Print Network (OSTI)

We calculate the thermal spectral function of SYM plasma with finite density using holographic technique. We take the RN-AdS black hole as the dual gravity theory. In the presence of charge, 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. We also calculated photoemission rate of SYM plasma from spectral function for light like momentum, AC conductivity and their density dependence. The suppression of the conductivity in high density is noticed, which might be yet another mechanism for the Jet quenching phenomena in RHIC experiment.

Kwanghyun Jo; Sang-Jin Sin

2010-05-03T23:59:59.000Z

128

Doppler Effect in Resonant Photoemission from SF6: Correlation between Doppler Profile and Auger Emission Anisotropy  

Science Journals Connector (OSTI)

Fragmentation of the SF6 molecule upon F 1s excitation has been studied by resonant photoemission. The F atomiclike Auger line exhibits the characteristic Doppler profile that depends on the direction of the photoelectron momentum relative to the polarization vector of the radiation as well as on the photon energy. The measured Doppler profiles are analyzed by the model simulation that takes account of the anisotropy of the Auger emission in the molecular frame. The Auger anisotropy extracted from the data decreases with an increase in the F-SF5 internuclear distance.

M. Kitajima; K. Ueda; A. De Fanis; T. Furuta; H. Shindo; H. Tanaka; K. Okada; R. Feifel; S. L. Sorensen; F. Gel’mukhanov; A. Baev; H. Ågren

2003-11-20T23:59:59.000Z

129

Electronic and structural properties of the InP(1 0 0)(2 × 4) surface studied by core-level photoemission and scanning tunneling microscopy  

Science Journals Connector (OSTI)

The (2 × 4)-reconstructed InP(1 0 0) surfaces have been investigated by scanning tunneling microscopy (STM) and synchrotron-radiation core-level photoelectron spectroscopy. STM observations show that the ?2 model describes the atomic structure of the InP(1 0 0)(2 × 4) surface in a limited range of the surface-preparation conditions, as predicted theoretically but not previously observed. STM results also support the accuracy of the previously found mixed-dimer structure for the InP(1 0 0)(2 × 4) surface under less P-rich conditions. A study of P 2p core-level photoelectron spectra, measured with different surface-sensitivity conditions, demonstrates that P 2p photoemission from the mixed-dimer InP(1 0 0)(2 × 4) surface consists of at least two surface-core-level-shift (SCLS) components which have kinetic energies approximately 0.4 eV higher and 0.3 eV lower than the bulk emission. On the basis of the surface-sensitivity difference between these SCLSs, they are related to the third-layer and top-layer P sites in the mixed-dimer structure, respectively.

P. Laukkanen; J. Pakarinen; M. Ahola-Tuomi; M. Kuzmin; R.E. Perälä; I.J. Väyrynen; A. Tukiainen; V. Rimpiläinen; M. Pessa; M. Adell; J. Sadowski

2006-01-01T23:59:59.000Z

130

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

SciTech Connect

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

131

Ethylene adsorption on Si(100)2×1:?A high-resolution photoemission study  

Science Journals Connector (OSTI)

The adsorption of ethylene on Si(100)2×1 has been investigated at room temperature by high-resolution synchrotron radiation photoemission in the exposure range: 1–1000 L. A consistent picture in favor of molecularly di-? bonded ethylene is obtained from the analysis of the photoemission spectral features, which shows the progressive decreasing of the surface states in the valence band and the Si 2p features related to the surface dimers upon adsorption. By careful fitting of the Si 2p complex envelope, the appearance of a component in the Si 2p core-level spectrum is evidenced already after 1 L exposure to ethylene. This component, which grows with exposure, is assigned to the formation of two Si-C bonds per dimer as a result of ethylene adsorption. The line-shape analysis by model functions permits us to follow the symmetrization of Si-Si dimers, which are known to be asymmetric on the clean surface, and the growth of a Si-C related spectral component upon adsorption. Relative quantitative analysis of the various peak components suggests that the intensity increase of the new component almost completely parallels the progressive decrease of the surface dimer components. No evidence for carbide formation has been found from the C 1s spectrum.

M. P. Casaletto; R. Zanoni; M. Carbone; M. N. Piancastelli; L. Aballe; K. Weiss; K. Horn

2000-12-15T23:59:59.000Z

132

High Speed H2O Concentration Measurements Using Absorption Spectroscopy to Monitor Exhaust Gas  

SciTech Connect

This paper demonstrates the potential for fast absorption spectroscopy measurements in diesel-engine exhaust to track H2O concentration transients. Wavelength-agile absorption spectroscopy is an optical technique that measures broadband absorption spectra between 10kHz and 100 MHz. From these measured spectra, gas temperature and absorber concentration can be determined. The Fourier-domain mode-locking (FDML) laser is becoming recognized as one of the most robust and reliable wavelength-agile sources available. H2O concentration measurements during combustion events at crank angle resolved speeds are beneficial for a wide variety of applications, such as product improvements for industry, control and reliability checks for experimental researchers, and measures of fit for numerical simulations. The difficulties associated with measuring diesel exhaust compared to in-cylinder measurements are discussed. A full description of the experimental configuration and data processing is explained. Measurements of engine exhaust H2O transients with 10- s temporal resolution are presented for a range of engine conditions.

Kranendonk, Laura [ORNL; Parks, II, James E [ORNL; Prikhodko, Vitaly Y [ORNL; Partridge Jr, William P [ORNL

2008-01-01T23:59:59.000Z

133

Photoelectrochemical Processes at n-GaAs(100)/Aqueous HCl Electrolyte Interface: A Synchrotron Photoemission Spectroscopy Study of Emersed Electrodes  

Science Journals Connector (OSTI)

Processes occurring at the semiconductor/electrolyte interfaces are very complex and include interrelated ion adsorption, surface bond breaking (corrosion), as well as charge transfer from semiconductor conduction and valence bands to species in the solution for reduction and oxidation reactions, respectively. ... As the processing is ultraclean and has been integrated to the UHV system, even differences in the electronic structures could be derived. ... The processes of gallium chlorides and elemental arsenic formation are accelerated under irradiation with visible light, which clearly illustrates the participation of photo holes in the photoelectrochemical etching process. ...

Mikhail V. Lebedev; Wolfram Calvet; Thomas Mayer; Wolfram Jaegermann

2014-05-30T23:59:59.000Z

134

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

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S. - School of Nuclear Engineering, Purdue University Collection: Plasma Physics and Fusion 3 Surface-Induced Dissociation Kinetics The research is designed to improve...

135

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

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

136

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

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Department of Theory Collection: Physics ; Chemistry 92 Evolution of a Two-Dimensional Band Structure at a Self-Assembling Interface A. D. Miller, K. J. Gaffney, S....

137

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

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consequences of a thermal pulse... . Schematic drawing of the time-resolved ellipsometer. Pump pulses thermally excite a thin Au film deposited... 1 Time-resolved ellipsometry for...

138

Thermal reactions of disilane on Si(100) studied by synchrotron-radiation photoemission  

Science Journals Connector (OSTI)

H-terminated Si(100) surfaces were formed by saturation exposure of Si(100) to disilane at room temperature. Annealing these surfaces to progressively higher temperatures resulted in hydrogen desorption. This process, of basic importance to the growth of Si by atomic layer epitaxy using disilane, was studied by synchrotron-radiation photoemission. The Si 2p core-level line shape, the position of the Fermi level within the band gap, the work function, and the ionization potential were measured as a function of annealing temperature. These results revealed two steps in the thermal reaction preceding the recovery of the clean surface. The dihydride radicals on the surface are converted to monohydride radicals at 500–610 K, and the monohydride radicals decompose at 700–800 K.

D.-S. Lin; T. Miller; T.-C. Chiang; R. Tsu; J. E. Greene

1993-10-15T23:59:59.000Z

139

Thermal reactions of disilane on Si(100) studied by synchrotron-radiation photoemission  

SciTech Connect

H-terminated Si(100) surfaces were formed by saturation exposure of Si(100) to disilane at room temperature. Annealing these surfaces to progressively higher temperatures resulted in hydrogen desorption. This process, of basic importance to the growth of Si by atomic layer epitaxy using disilane, was studied by synchrotron-radiation photoemission. The Si 2[ital p] core-level line shape, the position of the Fermi level within the band gap, the work function, and the ionization potential were measured as a function of annealing temperature. These results revealed two steps in the thermal reaction preceding the recovery of the clean surface. The dihydride radicals on the surface are converted to monohydride radicals at 500--610 K, and the monohydride radicals decompose at 700--800 K.

Lin, D.; Miller, T.; Chiang, T. (Department of Physics and Materials Research Laboratory, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, Illinois 61801-3080 (United States)); Tsu, R.; Greene, J.E. (Department of Materials Science and Engineering, Coordinated Science Laboratory, and Materials Research Laboratory, University of Illinois at Urbana-Champaign, 1304 West Green Street, Urbana, Illinois 61801-3080 (United States))

1993-10-15T23:59:59.000Z

140

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

SciTech Connect

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

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.


141

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

SciTech Connect

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

142

X-ray Imaging Workshop  

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Imaging and Spectro-microscopy: Imaging and Spectro-microscopy: the Present and the Future Stanford Synchrotron Radiation Laboratory October 8-9, 2002 Organizers: John Miao & Keith Hodgson A workshop on "X-ray Imaging and Spectro-microscopy: the Present and the Future" was held on October 8-9, 2002. This workshop, organized by John Miao (SSRL) and Keith Hodgson (SSRL) provided a forum to discuss the scientific applications of a variety of imaging and spectro-microscopic techniques, including photoemission electron microscopy (PEEM), angle resolved photoemission spectroscopy (ARPES), coherent diffraction imaging, x-ray microscopy, micro-tomography, holographic imaging, and x-ray micro-probe. Twelve invited speakers discussed the important scientific applications of these techniques, and also predicted the future scientific directions with the advance of instrumentation and x-ray sources. The workshop was well attended with over fifty registered attendees.

143

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

SciTech Connect

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

144

Awards  

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Awards Print Awards Print Recent awards given to ALS staff and users in recognition of their scientific and technical achievements. ALS users and staff are invited to send us information about recent awards by completing this form or by sending an email to This e-mail address is being protected from spambots. You need JavaScript enabled to view it . 2013 December In September, Shuyun Zhou, a previous ALS postdoctoral fellow, received "Outstanding Young Scholar Award" from Qiu Shi Science and Technology Foundation. Shuyun Zhou is currently an associate professor at the Department of Physics at Tsinghua University, Beijing. Before returning to her home university in 2012, she had built her track record from 10 years of research conducted at the ALS, initially as a Ph.D. student of UC Berkeley and ALS doctoral fellow, later as ALS postdoc fellow and project scientist from Materials Sciences Division. Her major achievements include electronic structure studies of graphene using angle-resolved photoemission spectroscopy, and ultrafast dynamic studies of localized electronic orderings in quantum materials using ultrafast time-resolved resonant X-ray scattering. While building her lab-based ultrafast time- and angle-resolved photoemission program at Tsinghua University, she has continued close collaboration with the ALS and recent progress has been made on the intriguing coupling between a topological insulator and a high temperature superconductor.

145

Awards  

NLE Websites -- All DOE Office Websites (Extended Search)

Awards Awards Awards Print Wednesday, 29 July 2009 00:00 Recent awards given to ALS staff and users in recognition of their scientific and technical achievements. ALS users and staff are invited to send us information about recent awards by completing this form or by sending an email to This e-mail address is being protected from spambots. You need JavaScript enabled to view it . 2013 December In September, Shuyun Zhou, a previous ALS postdoctoral fellow, received "Outstanding Young Scholar Award" from Qiu Shi Science and Technology Foundation. Shuyun Zhou is currently an associate professor at the Department of Physics at Tsinghua University, Beijing. Before returning to her home university in 2012, she had built her track record from 10 years of research conducted at the ALS, initially as a Ph.D. student of UC Berkeley and ALS doctoral fellow, later as ALS postdoc fellow and project scientist from Materials Sciences Division. Her major achievements include electronic structure studies of graphene using angle-resolved photoemission spectroscopy, and ultrafast dynamic studies of localized electronic orderings in quantum materials using ultrafast time-resolved resonant X-ray scattering. While building her lab-based ultrafast time- and angle-resolved photoemission program at Tsinghua University, she has continued close collaboration with the ALS and recent progress has been made on the intriguing coupling between a topological insulator and a high temperature superconductor.

146

Awards  

NLE Websites -- All DOE Office Websites (Extended Search)

Awards Print Awards Print Recent awards given to ALS staff and users in recognition of their scientific and technical achievements. ALS users and staff are invited to send us information about recent awards by completing this form or by sending an email to This e-mail address is being protected from spambots. You need JavaScript enabled to view it . 2013 December In September, Shuyun Zhou, a previous ALS postdoctoral fellow, received "Outstanding Young Scholar Award" from Qiu Shi Science and Technology Foundation. Shuyun Zhou is currently an associate professor at the Department of Physics at Tsinghua University, Beijing. Before returning to her home university in 2012, she had built her track record from 10 years of research conducted at the ALS, initially as a Ph.D. student of UC Berkeley and ALS doctoral fellow, later as ALS postdoc fellow and project scientist from Materials Sciences Division. Her major achievements include electronic structure studies of graphene using angle-resolved photoemission spectroscopy, and ultrafast dynamic studies of localized electronic orderings in quantum materials using ultrafast time-resolved resonant X-ray scattering. While building her lab-based ultrafast time- and angle-resolved photoemission program at Tsinghua University, she has continued close collaboration with the ALS and recent progress has been made on the intriguing coupling between a topological insulator and a high temperature superconductor.

147

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

SciTech Connect

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

148

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

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

149

Journal of Electron Spectroscopy and Related Phenomena 104 (1999) 99107 XPS and EELS study of the bismuth selenide  

E-Print Network (OSTI)

and Se Synchroton-Radiation Photoemission study of the (polycrystalline) and Bi Se (monocrystal) samples2

Soares, Edmar Avellar

150

Resonance Effects in Photoemission from TiO2-capped Mo/Si Multilayer Mirrors for Extreme Ultraviolet Applications  

SciTech Connect

In the unbaked vacuum systems of extreme ultraviolet (EUV) lithography steppers, oxide formation and carbon growth on Mo/Si multilayer mirrors (MLMs) are competing processes leading to reflectivity loss. A major contribution to this mirror degradation is a series of surface reactions that are thought to be driven in large part by photoemitted electrons. In this paper, we focus on the resonance effects in photoemission from Mo/Si MLMs protected by thin TiO{sub 2} cap layers. In the vicinity of the resonant energy of the mirror, the energy flux of the EUV radiation forming standing wave oscillates throughout the multilayer stack. As a result, light absorption followed by the emission of photoelectrons becomes a complex process that varies rapidly with depth and photon energy. The electron emission is characterized as a function of the EUV photon energy, the angle of incidence, and the position of the standing wave with respect to the solid/vacuum interface. In our experiments, the position of the standing wave was controlled both by deliberately varying the thickness of the Si terminating layer (of the Mo/Si stack) and by depositing C films of various thicknesses on the TiO{sub 2}. The experimental data are compared with model simulations to examine the changes in photoemission yield due to the presence of carbon and to the changes in the position of the standing wave. We find that carbon deposition can have a dramatic impact on the yield and, therefore, on the rates of electron mediated reactions at the surface.

N Faradzhev; B Yakshinskiy; E Starodub; T Madey; S Hill; S Grantham; T Lucatorto; S Yulin; E Vescovo; J Keister

2011-12-31T23:59:59.000Z

151

Electronic structures of GeSe2 in crystalline, amorphous, and Ag-photodoped amorphous phases studied by photoemission and optical spectra  

Science Journals Connector (OSTI)

Both valence and conduction bands in crystalline, amorphous, and Ag-photodoped GeSe2 are studied by a combination of photoemission, core-exciton, and reflectance spectra by the use of synchrotron radiation. Two conduction-band levels are clarified through observation of Se and Ge 3d core-exciton spectra in both crystalline and amorphous phases. With use of the two conduction-band states and valence-band structures observed in the photoemission spectra, the fine structures in the energy second derivative of the dielectric-response spectra in the region of 1–20 eV are successfully interpreted. The fine structures in the amorphous spectra closely correspond to those in the crystalline spectra in energy. The binding energy of the lowest core excitons in amorphous GeSe2 is slightly smaller than that in the crystal. Core excitons are found to be smeared out in photodoped spectra.

Koichi Inoue; Toshiharu Katayama; Koji Kawamoto; Kazuo Murase

1987-05-15T23:59:59.000Z

152

Studies Bolster Promise of Topological Insulators  

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Studies Bolster Promise of Studies Bolster Promise of Topological Insulators Studies Bolster Promise of Topological Insulators Print Tuesday, 27 November 2012 00:00 A few years ago, a strange new material began to drive research in condensed-matter physics around the world. First theorized and then discovered by researchers at Berkeley Lab and their colleagues in other institutions, these "strong 3D topological insulators"-TIs for short-are seemingly mundane semiconductors with startling properties. Not only are they promising materials for energy-conserving electronic applications, they provide a fascinating medium for possibly observing still-theoretical particles that could play a major role in quantum computing. Two angle-resolved photoemission spectroscopy (ARPES) studies recently performed at ALS Beamline 12.0.1 improve the prospects for the practical application of TIs in advanced devices.

153

Influence of Topological Spin Fluctuations on Charge Transport  

NLE Websites -- All DOE Office Websites (Extended Search)

Influence of Topological Spin Fluctuations on Charge Transport Print Influence of Topological Spin Fluctuations on Charge Transport Print Layered transition metal oxides are the focus of intense research efforts because they might clarify the superconducting mechanism of cuprate high-temperature superconductors (HTSCs). A case in point is NaxCoO2 with x = 0.7, which is a parent compound for a family of cobaltites that exhibits superconductivity. This class of materials is also thought to be ideal for detecting the long-sought resonating valence bond (RVB) state of matter proposed by Philip Anderson of Princeton University in 1973. Researchers from Princeton University and ALS are the first to use angle-resolved photoemission spectroscopy (ARPES) to demonstrate the strongly electron correlated nature of this material and to provide evidence that charge transport is strongly influenced by topological spin frustration.

154

Studies Bolster Promise of Topological Insulators  

NLE Websites -- All DOE Office Websites (Extended Search)

Studies Bolster Promise of Topological Insulators Print Studies Bolster Promise of Topological Insulators Print A few years ago, a strange new material began to drive research in condensed-matter physics around the world. First theorized and then discovered by researchers at Berkeley Lab and their colleagues in other institutions, these "strong 3D topological insulators"-TIs for short-are seemingly mundane semiconductors with startling properties. Not only are they promising materials for energy-conserving electronic applications, they provide a fascinating medium for possibly observing still-theoretical particles that could play a major role in quantum computing. Two angle-resolved photoemission spectroscopy (ARPES) studies recently performed at ALS Beamline 12.0.1 improve the prospects for the practical application of TIs in advanced devices.

155

First Direct Observation of Spinons and Holons  

NLE Websites -- All DOE Office Websites (Extended Search)

First Direct Observation of Spinons and Holons Print First Direct Observation of Spinons and Holons Print Spin and charge are inseparable traits of an electron, but in one-dimensional solids, a 40-year-old theory predicts their separation into "collective" modes-as independent excitation quanta called spinons and holons. Angle-resolved photoemission spectroscopy (ARPES) should provide the most direct evidence of this spin-charge separation, as the single quasiparticle peak splits into a spinon-holon two-peak structure. However, despite extensive ARPES experiments, the unambiguous observation of the two-peak structure has remained elusive. Working at the ALS, a team of researchers from Korea, Japan, and the U.S. has now observed electron spin-charge separation in a one-dimensional solid. These results hold implications for future developments in several key areas of advanced technology, including high-temperature superconductors, nanowires, and spintronics.

156

Influence of Topological Spin Fluctuations on Charge Transport  

NLE Websites -- All DOE Office Websites (Extended Search)

Influence of Topological Spin Fluctuations on Charge Transport Print Influence of Topological Spin Fluctuations on Charge Transport Print Layered transition metal oxides are the focus of intense research efforts because they might clarify the superconducting mechanism of cuprate high-temperature superconductors (HTSCs). A case in point is NaxCoO2 with x = 0.7, which is a parent compound for a family of cobaltites that exhibits superconductivity. This class of materials is also thought to be ideal for detecting the long-sought resonating valence bond (RVB) state of matter proposed by Philip Anderson of Princeton University in 1973. Researchers from Princeton University and ALS are the first to use angle-resolved photoemission spectroscopy (ARPES) to demonstrate the strongly electron correlated nature of this material and to provide evidence that charge transport is strongly influenced by topological spin frustration.

157

Studies Bolster Promise of Topological Insulators  

NLE Websites -- All DOE Office Websites (Extended Search)

Studies Bolster Promise of Topological Insulators Print Studies Bolster Promise of Topological Insulators Print A few years ago, a strange new material began to drive research in condensed-matter physics around the world. First theorized and then discovered by researchers at Berkeley Lab and their colleagues in other institutions, these "strong 3D topological insulators"-TIs for short-are seemingly mundane semiconductors with startling properties. Not only are they promising materials for energy-conserving electronic applications, they provide a fascinating medium for possibly observing still-theoretical particles that could play a major role in quantum computing. Two angle-resolved photoemission spectroscopy (ARPES) studies recently performed at ALS Beamline 12.0.1 improve the prospects for the practical application of TIs in advanced devices.

158

First Direct Observation of Spinons and Holons  

NLE Websites -- All DOE Office Websites (Extended Search)

First Direct Observation of Spinons and Holons Print First Direct Observation of Spinons and Holons Print Spin and charge are inseparable traits of an electron, but in one-dimensional solids, a 40-year-old theory predicts their separation into "collective" modes-as independent excitation quanta called spinons and holons. Angle-resolved photoemission spectroscopy (ARPES) should provide the most direct evidence of this spin-charge separation, as the single quasiparticle peak splits into a spinon-holon two-peak structure. However, despite extensive ARPES experiments, the unambiguous observation of the two-peak structure has remained elusive. Working at the ALS, a team of researchers from Korea, Japan, and the U.S. has now observed electron spin-charge separation in a one-dimensional solid. These results hold implications for future developments in several key areas of advanced technology, including high-temperature superconductors, nanowires, and spintronics.

159

First Observation of Plasmarons in Graphene  

NLE Websites -- All DOE Office Websites (Extended Search)

First Observation of Plasmarons First Observation of Plasmarons in Graphene First Observation of Plasmarons in Graphene Print Wednesday, 30 June 2010 00:00 An international team of scientists performing angle-resolved photoemission spectroscopy (ARPES) experiments at ALS Beamline 7.0.1 have found that composite particles called plasmarons play a vital role in determining graphene's properties. A plasmaron consists of a charge carrier (electron or hole) coupled with a plasmon-an electron density wave. Although plasmarons were proposed theoretically in the late 1960s, and indirect evidence of them has been found, this work is the first observation of their distinct energy bands in graphene, or indeed in any material. The discovery may hasten the day when graphene can be used for "plasmonics" to build ultrafast computers-perhaps even room-temperature quantum computers-plus a wide range of other tools and applications.

160

First Observation of Plasmarons in Graphene  

NLE Websites -- All DOE Office Websites (Extended Search)

First Observation of Plasmarons in Graphene Print First Observation of Plasmarons in Graphene Print An international team of scientists performing angle-resolved photoemission spectroscopy (ARPES) experiments at ALS Beamline 7.0.1 have found that composite particles called plasmarons play a vital role in determining graphene's properties. A plasmaron consists of a charge carrier (electron or hole) coupled with a plasmon-an electron density wave. Although plasmarons were proposed theoretically in the late 1960s, and indirect evidence of them has been found, this work is the first observation of their distinct energy bands in graphene, or indeed in any material. The discovery may hasten the day when graphene can be used for "plasmonics" to build ultrafast computers-perhaps even room-temperature quantum computers-plus a wide range of other tools and applications.

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161

Studies Bolster Promise of Topological Insulators  

NLE Websites -- All DOE Office Websites (Extended Search)

Studies Bolster Promise of Topological Insulators Print Studies Bolster Promise of Topological Insulators Print A few years ago, a strange new material began to drive research in condensed-matter physics around the world. First theorized and then discovered by researchers at Berkeley Lab and their colleagues in other institutions, these "strong 3D topological insulators"-TIs for short-are seemingly mundane semiconductors with startling properties. Not only are they promising materials for energy-conserving electronic applications, they provide a fascinating medium for possibly observing still-theoretical particles that could play a major role in quantum computing. Two angle-resolved photoemission spectroscopy (ARPES) studies recently performed at ALS Beamline 12.0.1 improve the prospects for the practical application of TIs in advanced devices.

162

Tuning of the Metal-Insulator Transition via Alkali Adsorption  

NLE Websites -- All DOE Office Websites (Extended Search)

Tuning of the Metal-Insulator Transition via Alkali Adsorption Print Tuning of the Metal-Insulator Transition via Alkali Adsorption Print Turning a material from an insulator to a metal, or vice versa, by light irradiation, exposure to electric or magnetic fields, or applying small changes in temperature, pressure, or doping-such intriguing control of a material's electronic properties is possible by exploiting strongly interacting or "correlated" electrons. Now a team of researchers from the University of Kiel in Germany and the ALS has found a novel, surprising way to continuously transform a layered metallic transition-metal compound, TaS2, into an insulator. Using angle-resolved photoemission spectroscopy (ARPES), they have demonstrated that adsorption of alkali atoms onto this material's surface gradually makes it more insulating, although in general, alkali adsorption should lead to more metallic behavior, as alkali atoms easily give away their loosely bound outermost electron.

163

First Observation of Plasmarons in Graphene  

NLE Websites -- All DOE Office Websites (Extended Search)

First Observation of Plasmarons in Graphene Print First Observation of Plasmarons in Graphene Print An international team of scientists performing angle-resolved photoemission spectroscopy (ARPES) experiments at ALS Beamline 7.0.1 have found that composite particles called plasmarons play a vital role in determining graphene's properties. A plasmaron consists of a charge carrier (electron or hole) coupled with a plasmon-an electron density wave. Although plasmarons were proposed theoretically in the late 1960s, and indirect evidence of them has been found, this work is the first observation of their distinct energy bands in graphene, or indeed in any material. The discovery may hasten the day when graphene can be used for "plasmonics" to build ultrafast computers-perhaps even room-temperature quantum computers-plus a wide range of other tools and applications.

164

Observation of a Macroscopically Quantum-Entangled Insulator  

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Observation of a Macroscopically Observation of a Macroscopically Quantum-Entangled Insulator Observation of a Macroscopically Quantum-Entangled Insulator Print Wednesday, 27 May 2009 00:00 It has recently been proposed that insulators with large band gaps and strong spin-orbit coupling can host a new phase of quantum matter called a topological insulator that is characterized by entangled wavefunctions. The proposal has now been realized by an international collaboration led by researchers from Princeton University who studied the electronic structure of insulating alloys of bismuth and antimony by means of angle-resolved photoemission spectroscopy (ARPES) and spin-resolved ARPES. Their results constitute the first direct experimental evidence of a topological insulator in nature that is fully quantum entangled. In the future, a detailed study of topological order and quantum entanglement using their method can potentially pave the way for fault-tolerant (topological) quantum computing.

165

ARPES Provides Direct Evidence of Spin-Wave Coupling  

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ARPES Provides Direct Evidence of Spin-Wave Coupling Print ARPES Provides Direct Evidence of Spin-Wave Coupling Print The electronic properties of a metal are determined by the dynamical behavior of its conduction electrons. Conventional band theory accounts for the interaction of the electrons with the static ion lattice. However, coupling to further microscopic degrees of freedom can alter the electron dynamics considerably. For example, "conventional" superconductivity emerges as a result of the electrons' interaction with lattice vibrations (phonons). In magnetic materials, coupling with spin waves (magnons) is also expected. Such interactions may contribute to high-temperature superconductivity in novel materials. Unfortunately, lattice vibrations and spin waves have similar energy scales, hindering detailed study. Researchers have taken a new approach in analyzing the electron bands of ferromagnetic iron. Angle-resolved photoemission spectroscopy (ARPES) provides direct spectroscopic evidence of altered electron mass and energy (quasiparticle formation) in a magnetic solid due to coupling with spin waves.

166

Observation of a Macroscopically Quantum-Entangled Insulator  

NLE Websites -- All DOE Office Websites (Extended Search)

Observation of a Macroscopically Quantum-Entangled Insulator Print Observation of a Macroscopically Quantum-Entangled Insulator Print It has recently been proposed that insulators with large band gaps and strong spin-orbit coupling can host a new phase of quantum matter called a topological insulator that is characterized by entangled wavefunctions. The proposal has now been realized by an international collaboration led by researchers from Princeton University who studied the electronic structure of insulating alloys of bismuth and antimony by means of angle-resolved photoemission spectroscopy (ARPES) and spin-resolved ARPES. Their results constitute the first direct experimental evidence of a topological insulator in nature that is fully quantum entangled. In the future, a detailed study of topological order and quantum entanglement using their method can potentially pave the way for fault-tolerant (topological) quantum computing.

167

ARPES Provides Direct Evidence of Spin-Wave Coupling  

NLE Websites -- All DOE Office Websites (Extended Search)

ARPES Provides Direct Evidence of Spin-Wave Coupling Print ARPES Provides Direct Evidence of Spin-Wave Coupling Print The electronic properties of a metal are determined by the dynamical behavior of its conduction electrons. Conventional band theory accounts for the interaction of the electrons with the static ion lattice. However, coupling to further microscopic degrees of freedom can alter the electron dynamics considerably. For example, "conventional" superconductivity emerges as a result of the electrons' interaction with lattice vibrations (phonons). In magnetic materials, coupling with spin waves (magnons) is also expected. Such interactions may contribute to high-temperature superconductivity in novel materials. Unfortunately, lattice vibrations and spin waves have similar energy scales, hindering detailed study. Researchers have taken a new approach in analyzing the electron bands of ferromagnetic iron. Angle-resolved photoemission spectroscopy (ARPES) provides direct spectroscopic evidence of altered electron mass and energy (quasiparticle formation) in a magnetic solid due to coupling with spin waves.

168

Observation of a Macroscopically Quantum-Entangled Insulator  

NLE Websites -- All DOE Office Websites (Extended Search)

Observation of a Macroscopically Quantum-Entangled Insulator Print Observation of a Macroscopically Quantum-Entangled Insulator Print It has recently been proposed that insulators with large band gaps and strong spin-orbit coupling can host a new phase of quantum matter called a topological insulator that is characterized by entangled wavefunctions. The proposal has now been realized by an international collaboration led by researchers from Princeton University who studied the electronic structure of insulating alloys of bismuth and antimony by means of angle-resolved photoemission spectroscopy (ARPES) and spin-resolved ARPES. Their results constitute the first direct experimental evidence of a topological insulator in nature that is fully quantum entangled. In the future, a detailed study of topological order and quantum entanglement using their method can potentially pave the way for fault-tolerant (topological) quantum computing.

169

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

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

170

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

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

171

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

SciTech Connect

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

172

Are cobaltates conventional? An ARPES viewpoint  

SciTech Connect

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

173

Fabrication of Li-intercalated bilayer graphene  

Science Journals Connector (OSTI)

We have succeeded in fabricating Li-intercalated bilayer graphene on silicon carbide. The low-energy electron diffraction from Li-deposited bilayer graphene shows a sharp 3 × 3 R 30° pattern in contrast to Li-deposited monolayer graphene. This indicates that Li atoms are intercalated between two adjacent graphene layers and take the same well-ordered superstructure as in bulk C6Li. The angle-resolved photoemission spectroscopy has revealed that Li atoms are fully ionized and the ? bands of graphene are systematically folded by the superstructure of intercalated Li atoms producing a snowflake-like Fermi surface centered at the ? point. The present result suggests a high potential of Li-intercalated bilayer graphene for application to a nano-scale Li-ion battery.

K. Sugawara; K. Kanetani; T. Sato; T. Takahashi

2011-01-01T23:59:59.000Z

174

Topological insulator Bi 2 Se 3 thin films grown on double-layer graphene by molecular beam epitaxy  

Science Journals Connector (OSTI)

Atomically flat thin films of topological insulator Bi 2 Se 3 have been grown on double-layer graphene formed on 6H–SiC(0001) substrate by molecular beam epitaxy. By a combined study of reflection high energy electron diffraction and scanning tunneling microscopy we identified the Se-rich condition and temperature criterion for layer-by-layer growth of epitaxial Bi 2 Se 3 films. The as-grown films without doping exhibit a low defect density of 1.0 ± 0.2 × 10 11 / cm 2 and become a bulk insulator at a thickness of ten quintuple layers as revealed by in situ angle resolved photoemission spectroscopy measurement.

Can-Li Song; Yi-Lin Wang; Ye-Ping Jiang; Yi Zhang; Cui-Zu Chang; Lili Wang; Ke He; Xi Chen; Jin-Feng Jia; Yayu Wang; Zhong Fang; Xi Dai; Xin-Cheng Xie; Xiao-Liang Qi; Shou-Cheng Zhang; Qi-Kun Xue; Xucun Ma

2010-01-01T23:59:59.000Z

175

First Observation of Plasmarons in Graphene  

NLE Websites -- All DOE Office Websites (Extended Search)

First Observation of Plasmarons in Graphene Print First Observation of Plasmarons in Graphene Print An international team of scientists performing angle-resolved photoemission spectroscopy (ARPES) experiments at ALS Beamline 7.0.1 have found that composite particles called plasmarons play a vital role in determining graphene's properties. A plasmaron consists of a charge carrier (electron or hole) coupled with a plasmon-an electron density wave. Although plasmarons were proposed theoretically in the late 1960s, and indirect evidence of them has been found, this work is the first observation of their distinct energy bands in graphene, or indeed in any material. The discovery may hasten the day when graphene can be used for "plasmonics" to build ultrafast computers-perhaps even room-temperature quantum computers-plus a wide range of other tools and applications.

176

First Direct Observation of Spinons and Holons  

NLE Websites -- All DOE Office Websites (Extended Search)

First Direct Observation of Spinons and Holons Print First Direct Observation of Spinons and Holons Print Spin and charge are inseparable traits of an electron, but in one-dimensional solids, a 40-year-old theory predicts their separation into "collective" modes-as independent excitation quanta called spinons and holons. Angle-resolved photoemission spectroscopy (ARPES) should provide the most direct evidence of this spin-charge separation, as the single quasiparticle peak splits into a spinon-holon two-peak structure. However, despite extensive ARPES experiments, the unambiguous observation of the two-peak structure has remained elusive. Working at the ALS, a team of researchers from Korea, Japan, and the U.S. has now observed electron spin-charge separation in a one-dimensional solid. These results hold implications for future developments in several key areas of advanced technology, including high-temperature superconductors, nanowires, and spintronics.

177

Influence of Topological Spin Fluctuations on Charge Transport  

NLE Websites -- All DOE Office Websites (Extended Search)

Influence of Topological Spin Fluctuations on Charge Transport Print Influence of Topological Spin Fluctuations on Charge Transport Print Layered transition metal oxides are the focus of intense research efforts because they might clarify the superconducting mechanism of cuprate high-temperature superconductors (HTSCs). A case in point is NaxCoO2 with x = 0.7, which is a parent compound for a family of cobaltites that exhibits superconductivity. This class of materials is also thought to be ideal for detecting the long-sought resonating valence bond (RVB) state of matter proposed by Philip Anderson of Princeton University in 1973. Researchers from Princeton University and ALS are the first to use angle-resolved photoemission spectroscopy (ARPES) to demonstrate the strongly electron correlated nature of this material and to provide evidence that charge transport is strongly influenced by topological spin frustration.

178

First Observation of Plasmarons in Graphene  

NLE Websites -- All DOE Office Websites (Extended Search)

First Observation of Plasmarons in Graphene Print First Observation of Plasmarons in Graphene Print An international team of scientists performing angle-resolved photoemission spectroscopy (ARPES) experiments at ALS Beamline 7.0.1 have found that composite particles called plasmarons play a vital role in determining graphene's properties. A plasmaron consists of a charge carrier (electron or hole) coupled with a plasmon-an electron density wave. Although plasmarons were proposed theoretically in the late 1960s, and indirect evidence of them has been found, this work is the first observation of their distinct energy bands in graphene, or indeed in any material. The discovery may hasten the day when graphene can be used for "plasmonics" to build ultrafast computers-perhaps even room-temperature quantum computers-plus a wide range of other tools and applications.

179

EMSL - Spectroscopy and Diffraction  

NLE Websites -- All DOE Office Websites (Extended Search)

loss spectroscopy and electron backscatter diffraction Local Electrode Atom Probe tomography system with 355 nm UV laser and reflectron flight path for high mass resolution...

180

High Tc Superconductivity  

NLE Websites -- All DOE Office Websites (Extended Search)

by C. Kim (SSRL), D. H. Lu (Stanford), K. M. Shen (Stanford) and Z.-X. Shen (Stanford/SSRL) by C. Kim (SSRL), D. H. Lu (Stanford), K. M. Shen (Stanford) and Z.-X. Shen (Stanford/SSRL) Extensive research efforts to study the novel electronic properties of high-Tc superconductors and their related materials by angle-resolved photoemission spectroscopy at a recently commissioned Beam Line 5-4 (led by Z.-X. Shen) continue to be successful, producing many important results. These results, which are highlighted by five articles recently published in Physical Review Letters and one in Science, brought our understanding steps closer to solving the mystery of the high-Tc superconductivity. With the development of the latest generation of ultra-high resolution electron spectrometers in the past few years, the technique of angle resolved photoemission spectroscopy (ARPES) has recently experienced a renaissance. Nowhere is this revolution more evident than in the study of the high-temperature superconductors, which more than a decade after their discovery, continue to defy theoretical explanation. Recent ARPES experiments performed at Beam Line 5-4 have led to critical new discoveries about the fundamental nature of these mysterious superconductors and are now changing the way that the physics community views these materials. An excellent benchmark for the huge leap in detector resolution and technology is the recent work on Sr2RuO4. Although it belongs to a slightly different family than the high- temperature superconductors, its exotic superconducting mechanism (Tc = 1K) and complex electronic structure make it itself a fascinating material. In the past, due to poor resolutions, ARPES studies on this material were in disagreement with theory and other experimental techniques.

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

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

SciTech Connect

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

182

Nuclear Raman spectroscopy  

Science Journals Connector (OSTI)

An experiment is described in which the nuclear analog to Raman spectroscopy has been applied to 57Fe. The results of the experiment are given, and future applications of...

DePaola, B D; Wagal, S S; Collins, C B

1985-01-01T23:59:59.000Z

183

Electronic Spectroscopy & Dynamics  

SciTech Connect

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

184

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

SciTech Connect

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

185

EMSL: Capabilities: Spectroscopy and Diffraction  

NLE Websites -- All DOE Office Websites (Extended Search)

Spectroscopy and Diffraction Spectroscopy and Diffraction Additional Information Meet the Spectroscopy and Diffraction Experts Related EMSL User Projects Spectroscopy and Diffraction Tools are Applied to all Science Themes Tutorial: XPS Tools for Surface Analysis Spectroscopy and Diffraction brochure EMSL's suite of spectroscopy and diffraction instruments allows users to study solid-, liquid-, and gas-phase sample structure and composition with remarkable resolution. Ideal for integrated studies, spectrometers and diffractometers are easily coupled with EMSL's computational and modeling capabilities, allowing users to apply a multifaceted research approach for experimental data interpretation and gain fundamental understanding of scientific problems. At EMSL, spectroscopy and diffraction instruments are

186

SMB, X-ray Absorption Spectroscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Absorption Spectroscopy X-ray Absorption Spectroscopy X-ray absorption spectroscopy (XAS) is a well-established technique for simultaneous local geometric and electronic structure...

187

Resonant Raman spectroscopy of nanotubes  

Science Journals Connector (OSTI)

...Raman spectroscopy in carbons: from nanotubes to diamond compiled by Andrea C. Ferrari...Robertson Resonant Raman spectroscopy of nanotubes Christian Thomsen 1 Stephanie Reich 2...The experimental situation in carbon nanotubes is reviewed in view of these criteria...

2004-01-01T23:59:59.000Z

188

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

189

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

190

Ultrahigh vacuum sample mount for x-ray photoelectron spectroscopy up to very high temperature (150-1400 K)  

SciTech Connect

Spectroscopic studies are rarely performed at very high temperature, especially when combined with light from a synchrotron source. Demanding conditions of maintaining ultrahigh vacuum (UHV) during heating, together with the typically brief access to beam time at multiuser synchrotron end stations, may contribute to some of the reasons for the difficulty of such experiments. Consequently, a large number of materials with interesting properties and industrial applications at high temperature remain unexplored. The authors describe here a simple portable sample mount assembly that can be easily utilized at a beamline, with potential utility for a variety of spectroscopic measurements requiring elevated temperatures and an UHV environment. In the specific application described here, the authors use a resistive cartridge heater interfaced with a standard manipulator previously designed for cooling by liquid nitrogen with an UHV chamber and a cylindrical mirror analyzer for x-ray photoemission spectroscopy (XPS) [also known as electron spectroscopy for chemical analysis (ESCA)] at the Synchrotron Radiation Center in Stoughton, WI. The heater cartridge required only modest power to reach target temperatures using an open-loop temperature control. Finally, the authors describe the measurements of XPS (ESCA) and total-electron yield x-ray absorption spectroscopy on nanopowders and on single crystals grown by them. They emphasize the simplicity of the setup, which they believe would be of interest to groups performing measurements at large facilities, where access and time are both limited.

Williamsen, Mark S.; Ray, Shishir K.; Zou Ying; Dudek, John A.; Sen, Somaditya; Bissen, Mark; Kretsch, Laura; Palkar, Vaijayanti R.; Onellion, Marshall F.; Guptasarma, Prasenjit [Department of Physics, University of Wisconsin-Milwaukee, 1900 E. Kenwood Blvd., Milwaukee, Wisconsin 53211 (United States); Synchrotron Radiation Center, 3731 Schneider Dr., Stoughton, Wisconsin 53589 (United States); Department of Electrical Engineering, Indian Institute of Technology Bombay, Mumbai 400076 (India); Department of Physics, University of Wisconsin--Madison, 1150 University Ave., Madison, Wisconsin 53706 (United States); Department of Physics, University of Wisconsin-Milwaukee, 1900 E. Kenwood Blvd., Milwaukee, Wisconsin 53211 (United States)

2011-05-15T23:59:59.000Z

191

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

192

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

193

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

194

Single molecule laser spectroscopy  

Science Journals Connector (OSTI)

Abstract In this article, we discussed some single molecule spectroscopy techniques and methods. We have chosen the simplicity in this survey based on our laboratory experience in this field. We concentrated on the imaging by both techniques the wide field and the scanning microscopes. Other imaging enhancements on the technique like extended resolution wide field, the total internal reflection imaging, and its derivatives are also reviewed. In addition to the imaging techniques, some diffusion techniques also are discussed like fluorescence correlation spectroscopy. The related methods like Forester resonance transfer, photo-induced electron transfer and anisotropy (steady state and time decay) are also discussed. In addition, we elucidated some simple details about the theory behind the FCS and its resulting curve fitting. This review is preceded by general introduction and ended with the conclusion.

Diaa Atta; Ali Okasha

2015-01-01T23:59:59.000Z

195

2008 Vibrational Spectroscopy  

SciTech Connect

The conference focuses on using vibrational spectroscopy to probe structure and dynamics of molecules in gases, liquids, and interfaces. 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 systems.

Philip J. Reid

2009-09-21T23:59:59.000Z

196

Point-contact spectroscopy  

Science Journals Connector (OSTI)

Micro-contacts between metals at low temperatures reveal non-linear structures in the current-voltage characteristics. These deviations from Ohm's law allow an energy-resolved spectroscopy of the interaction of the conduction electrons with elementary excitations (e.g. phonons) in a metal. To explain the method, the important parameters (electron mean free path versus contact dimension) in point-contact spectroscopy will be discussed together with examples of spectroscopic information obtained in various systems. Local temperature gradients in the contact region offer the possibility to study thermo-electric phenomena in small constrictions, such as thermal voltages in non-homogeneous contacts and quenching of the phonon-drag term in the thermo-power in homogeneous contacts. Besides these aspects of the point-contact technique, recent experiments will be shown with applications of point contacts other than just spectroscopy: magneto-resistance of a point contact, high-frequency rectification with a point contact as the non-linear element, electron focusing using a double point-contact set-up, electrical noise in constrictions and generation of phonons by means of point contacts.

A M Duif; A G M Jansen; P Wyder

1989-01-01T23:59:59.000Z

197

(Resonance ionization spectroscopy)  

SciTech Connect

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

198

Inner-shell electron spectroscopy and chemical properties of atoms and small molecules  

SciTech Connect

The program has been concerned with gas-phase carbon 1s photoelectron spectroscopy of a number of molecules of potential chemical interest. The primary goals have been to determine carbon 1s ionization energies with a view of relating these to other chemical properties such as electronegativity, acidity, basicity, and reactivity, in order to provide a better understanding of these fundamental properties. The role of electron-donating (methyl) and electron-withdrawing (fluoro) substituents on the carbon 1s ionization energies of substituted benzenes has been studied., and these results have been related to measurements of the reactivities of the same molecule as well as to their affinities for protons (basicity). Opportunities for investigation in unplanned areas have arisen, and the program has been modified to take advantage of these. One has been the realization that, under certain circumstances, inner-shell ionization energies may depend on the molecular conformation. Several examples of this phenomenon have been investigated and it has been shown that this technique provides a tool for the measurement of the energy differences between different conformers of the same substance. The other has been the demonstration that photoelectron recoil can lead to the excitation of vibrational modes that are forbidden in the normal view of photoemission and to rotational heating of the molecule that increases with the energy of the exciting radiation.

T. Darrah Thomas

2009-01-21T23:59:59.000Z

199

The light meson spectroscopy program  

SciTech Connect

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

200

SMB, X-ray Emission Spectroscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Emission Spectroscopy Beam Line 6-2b X-ray Emission Spectroscopy Beam Line 6-2b is an advanced spectroscopy experimental station on the multidisciplinary general user wiggler Beam...

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

SMB, X-Ray Spectroscopy & Imaging  

NLE Websites -- All DOE Office Websites (Extended Search)

Home X-Ray Spectroscopy & Imaging X-Ray Spectroscopy & Imaging SSRL has five hard X-ray Spectroscopy beamlines and three Microfocus Imaging beamlines dedicated to Biological and...

202

X-ray Photoelectron Spectroscopy (XPS) | EMSL  

NLE Websites -- All DOE Office Websites (Extended Search)

photoelectron spectroscopy (UPS), ion scattering spectroscopy (ISS), a clusterAr+ ion gun, and a five-axis automated stage with variable temperature sample environment at the...

203

Sum Frequency Generation for Surface Vibrational Spectroscopy...  

NLE Websites -- All DOE Office Websites (Extended Search)

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

204

Spectroscopy of Rf257  

Science Journals Connector (OSTI)

The isotope Rf257 was produced in the fusion-evaporation reaction Pb208(Ti50,n)Rf257. Reaction products were separated and identified by mass. Delayed spectroscopy of Rf257 and its decay products was performed. A partial decay scheme with configuration assignments is proposed based on ? hindrance factors. The excitation energy of the 1/2+[620] configuration in No253 is proposed. The energy of this 1/2+ state in a series of N=151 isotones increases with nuclear charge, reflecting an increase in the N=152 gap. This gap is deduced to grow substantially from 850 to 1400 keV between Z=94 and 102. An isomeric state in Rf257, with a half-life of 160-31+42??s, was discovered by detecting internal conversion electrons followed by ? decay. It is interpreted as a three-quasiparticle high-K isomer. A second group of internal conversion electrons, with a half-life of 4.1-1.3+2.4 s, followed by ? decay, was also observed. These events might originate from the decay of excited states in Lr257, populated by electron-capture decay of Rf257. Fission of Rf257 was unambiguously detected, with a branching ratio of bRfSF=0.02±0.01.

J. Qian; A. Heinz; T. L. Khoo; R. V. F. Janssens; D. Peterson; D. Seweryniak; I. Ahmad; M. Asai; B. B. Back; M. P. Carpenter; A. B. Garnsworthy; J. P. Greene; A. A. Hecht; C. L. Jiang; F. G. Kondev; T. Lauritsen; C. J. Lister; A. Robinson; G. Savard; R. Scott; R. Vondrasek; X. Wang; R. Winkler; S. Zhu

2009-06-22T23:59:59.000Z

205

Raman Spectroscopy of Microbial Pigments  

Science Journals Connector (OSTI)

...minireview, Raman spectroscopy has several advantages for pigment and carotenoid work. The...BF01923559 . 71. Garcia-Pichel, F . 1998. Solar ultraviolet and the evolutionary history...signal strength, adaptive strategies, solar radiation, and humidity. Astrobiology...

Jan Jehli?ka; Howell G. M. Edwards; Aharon Oren

2014-03-28T23:59:59.000Z

206

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

207

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

208

A mobile UHV-system designed for femtosecond time, energy and spin resolved photoelectron spectroscopy  

Science Journals Connector (OSTI)

We report on the design and tests of a completely mobile photoemission end station for femtosecond time, energy and spin resolved magnetodynamics experiments. The setup is designed for the use at free-electron la...

Thomas Michlmayr; Andreas Fognini; Thomas Bähler…

2013-06-01T23:59:59.000Z

209

Spectroscopy (XSD) | Advanced Photon Source  

NLE Websites -- All DOE Office Websites (Extended Search)

Useful Links Useful Links Spectroscopy Group (X-ray Science Division) The Spectroscopy Group operates the Sector-20 bending magnet (BM) and insertion device (ID) beamlines, and the bending magnet beamline at Sector-9. Beamlines 20-ID (Undulator A) Supported Techniques ·X-ray absorption fine structure (XAFS) ·Surface Diffraction ·X-ray Raman Scattering ·Resonant X-ray Emission Spectroscopy ·Micro-XAFS ·Confocal X-ray microscopy ·Micro-fluorescence ·Micro-XRD Discipline ·Material Science ·Environmental Science ·Chemistry Click [20-ID] under "Beamlines" above for technical information 20-BM Supported Techniques X-ray absorption fine structure (XAFS) Micro-fluorescence Micro-XAFS Micro-diffraction Discipline ·Material Science ·Environmental Science ·Chemistry Click [20-BM] under "Beamlines" above for technical information

210

Environmental Spectroscopy and Biogeochemistry Facility  

NLE Websites -- All DOE Office Websites (Extended Search)

ES&B Overview ES&B Overview Section 2-2-1 Environmental Spectroscopy and Biogeochemistry Facility The Environmental Spectroscopy and Biogeochemistry (ES&B) Facility focuses on environ- mental molecular science and application of the fundamental concepts of physical chemistry to the study of chemical reactions in heterogeneous natural materials, with an emphasis on soil and subsurface systems. The ES&B Facility staff, along with other Pacific Northwest National Laboratory (PNNL) staff, form a multidisciplinary research team with expertise in chemistry, mineral physics, geochemistry, soil chemistry, microbiology, hydrology, and environmental engineering. Capabilities Capabilities are available for materials characterization, aqueous- and solid-phase speciation

211

X-ray Absorption Spectroscopy  

SciTech Connect

This review gives a brief description of the theory and application of X-ray absorption spectroscopy, both X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS), especially, pertaining to photosynthesis. The advantages and limitations of the methods are discussed. Recent advances in extended EXAFS and polarized EXAFS using oriented membranes and single crystals are explained. Developments in theory in understanding the XANES spectra are described. The application of X-ray absorption spectroscopy to the study of the Mn4Ca cluster in Photosystem II is presented.

Yano, Junko; Yachandra, Vittal K.

2009-07-09T23:59:59.000Z

212

The scanning soft X-ray microscope at Hasylab: imaging and spectroscopy of photoelectrons, photoluminescence, desorbed ions, reflected, scattered and transmitted light  

Science Journals Connector (OSTI)

The scanning soft X-ray microscope operating at Hasylab/Desy has been developed to combine lateral and temporal resolution, tunability and various conventional spectroscopy techniques. Different mirror optics are used to form a microprobe in the energy range 15–1500 eV. A grazing incidence ellipsoidal mirror provides a resolution of 1 ?m over the entire energy range, and in the vacuum ultraviolet region below 30 eV, 0.15 ?m can be achieved with a Pt-coated Schwarzschild objective. Due to the large working distance of the optics used, the detection and analysis of several surface signals are comparatively simple. Detectors and spectrometers for photoelectrons, luminescence, fluorescence, desorbed ions, reflected, scattered and transmitted light are built in permanently into the microscope. Furthermore, some combinations of the different methods can be used for simultaneous measurements. In this paper the technical developments of recent years are described. A short representation of some exemplary applications will give an insight into the work of our group and illustrate the characteristics of the microscope. The following topics are discussed: cross-luminescence of barium fluoride, visible luminescence and degradation of porous silicon, photoluminescence of ceramics, chemical contrast in photoemission spectroscopy, and Bragg reflection as a contrast mechanism in X-ray microscopy.

J Voss

1997-01-01T23:59:59.000Z

213

Adiabatic Tip-Plasmon Focusing for Nano-Raman Spectroscopy. ...  

NLE Websites -- All DOE Office Websites (Extended Search)

Adiabatic Tip-Plasmon Focusing for Nano-Raman Spectroscopy. Adiabatic Tip-Plasmon Focusing for Nano-Raman Spectroscopy. Abstract: True nanoscale optical spectroscopy requires the...

214

7 - Raman spectroscopy of graphene  

Science Journals Connector (OSTI)

Abstract: The principles of Raman scattering and the properties of phonons and electrons in graphene are reviewed. The focus is on Raman spectroscopy of mono- and bilayer graphene, particularly perturbations that have a significant influence on the Raman spectra. The distinct behaviour of Raman modes of different orders is discussed.

M. Hulman

2014-01-01T23:59:59.000Z

215

Cryogenic Ion Chemistry and Spectroscopy  

Science Journals Connector (OSTI)

Cryogenic Ion Chemistry and Spectroscopy ... His research focuses on developing and applying cryogenic ion processing for the characterization of hydrogen bonding motifs in macromolecules and activated organometallic catalysts. ... In this Account, we discuss how cryogenic cooling, mass selection, and reactive processing together provide a powerful way to characterize ion structures as well as rationally synthesize labile reaction intermediates. ...

Arron B. Wolk; Christopher M. Leavitt; Etienne Garand; Mark A. Johnson

2013-08-23T23:59:59.000Z

216

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

217

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.

218

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.

219

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

SciTech Connect

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

220

The BEAR Beamline at Elettra  

SciTech Connect

The BEAR (Bending Magnet for Emission Absorption and Reflectivity) beamline is installed at the right exit of the 8.1 bending magnet at ELETTRA. The beamline - in operation since January 2003 - delivers linear and circularly polarized radiation in the 5 - 1600 eV energy range. The experimental station is composed of a UHV chamber for reflectivity, absorption, fluorescence and angle resolved photoemission measurements and a UHV chamber for in-situ sample preparation.

Nannarone, S.; Pasquali, L.; Selvaggi, G. [UdR-INFM Modena, Universita di Modena and Reggio Emilia, Via Vignolese 905, 41100 Modena (Italy); Borgatti, F.; DeLuisa, A.; Doyle, B.P.; Gazzadi, G.C.; Giglia, A.; Finetti, P.; Pedio, M. [TASC-INFM, MM building in Area Science Park, s.s.14 km 163.5, 34012 Basovizza, Trieste (Italy); Mahne, N. [TASC-INFM, Universita di Trieste, Trieste (Italy); Naletto, G.; Pelizzo, M.G.; Tondello, G. [LUXOR-INFM, Universita di Padova, Padua (Italy)

2004-05-12T23:59:59.000Z

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.


221

High-Speed Optical Spectroscopy  

E-Print Network (OSTI)

The large surveys and sensitive instruments of modern astronomy are turning ever more examples of variable objects, many of which are extending the parameter space to testing theories of stellar evolution and accretion. Future projects such as the Laser Interferometer Space Antenna (LISA) and the Large Synoptic Survey Telescope (LSST) will only add more challenging candidates to this list. Understanding such objects often requires fast spectroscopy, but the trend for ever larger detectors makes this difficult. In this contribution I outline the science made possible by high-speed spectroscopy, and consider how a combination of the well-known progress in computer technology combined with recent advances in CCD detectors may finally enable it to become a standard tool of astrophysics.

T. R. Marsh

2007-06-28T23:59:59.000Z

222

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

223

Quantitative tunneling spectroscopy of nanocrystals  

SciTech Connect

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

224

Superconducting Topological Insulators  

NLE Websites -- All DOE Office Websites (Extended Search)

Superconducting Topological Insulators Print Superconducting Topological Insulators Print Three-dimensional topological insulators (TIs), discovered experimentally in 2007-2009 by a Princeton-ALS collaboration, are a promising platform for developing the next generation of electronics. Electrons within one nanometer of a TI's surface move at high speeds in a "light-like" fashion. The quantum interactions that generate these electronic states cause individual electrons to be spin polarized even at room temperature and to strongly resist scattering from defects, naturally achieving some of the most desirable traits for computing components and next-generation "spintronics" technologies. More recent angle-resolved photoemission spectroscopy (ARPES) studies performed at ALS Beamlines 10.0.1 and 12.0.1 by the same collaboration have paved a way for these novel material properties to be taken even further. Their studies showed that by doping the TI, bismuth selenide, with copper, it's possible to make the topologically ordered electrons superconducting, dropping electrical resistance in the surface states all the way to zero.

225

Surprising Quasiparticle Interactions in Graphene  

NLE Websites -- All DOE Office Websites (Extended Search)

Surprising Quasiparticle Interactions in Graphene Print Surprising Quasiparticle Interactions in Graphene Print Until now, the world's electronics have been dominated by silicon, whose properties, while excellent, significantly limit the size and power consumption of today's computer chips. In order to develop ever smaller and more efficient devices, scientists have turned their attention to carbon, which can be formed into nanostructures like nanotubes, whose properties can be tuned from metallic to semiconducting. However, using carbon nanotubes for complex circuits is nearly impossible because their location and functionality in devices cannot be controlled at will, making them a poor substitute for silicon. Graphene, however, does not have these limitations. This single sheet of carbon atoms that is the building block of carbon nanotubes, C60 molecules, and graphite turns out to have similar functionality but with the added benefit that it can be grown with conventional methods and patterned into devices. Now, a group of scientists from Germany and the ALS, using angle-resolved photoemission spectroscopy (ARPES) at ALS Beamine 7.0.1, have succeeded in making the first measurement of the carrier lifetime in graphene over a wide energy scale and have found surprising new interactions that suggest new kinds of devices.

226

First Direct Evidence of Dirac Fermions in Graphite  

NLE Websites -- All DOE Office Websites (Extended Search)

Direct Evidence of Dirac Fermions in Graphite Print Direct Evidence of Dirac Fermions in Graphite Print The recent surge of interest in the electronic properties of graphene-that is, isolated layers of graphite just one atomic layer thick-has largely been driven by the discovery that electron mobility in graphene is ten times higher than in commercial-grade silicon, raising the possibility of high-efficiency, low-power, carbon-based electronics. Scientists attribute graphene's surprising current capacity (as well as a number of even stranger phenomena) to the presence of charge carriers that behave as if they are massless, "relativistic" quasiparticles called Dirac fermions. Harnessing these quasiparticles in real-world carbon-based devices, however, requires a deeper knowledge of their behavior under less-than-ideal circumstances, such as around defects, at edges, or in three dimensions-in other words, in graphite. At the ALS, a team of researchers using angle-resolved photoemission spectroscopy (ARPES) have now produced the first direct evidence of massless Dirac fermions in graphite coexisting with quasiparticles of finite effective mass and defect-induced localized states.

227

First Direct Evidence of Dirac Fermions in Graphite  

NLE Websites -- All DOE Office Websites (Extended Search)

Direct Evidence of Dirac Fermions in Graphite Print Direct Evidence of Dirac Fermions in Graphite Print The recent surge of interest in the electronic properties of graphene-that is, isolated layers of graphite just one atomic layer thick-has largely been driven by the discovery that electron mobility in graphene is ten times higher than in commercial-grade silicon, raising the possibility of high-efficiency, low-power, carbon-based electronics. Scientists attribute graphene's surprising current capacity (as well as a number of even stranger phenomena) to the presence of charge carriers that behave as if they are massless, "relativistic" quasiparticles called Dirac fermions. Harnessing these quasiparticles in real-world carbon-based devices, however, requires a deeper knowledge of their behavior under less-than-ideal circumstances, such as around defects, at edges, or in three dimensions-in other words, in graphite. At the ALS, a team of researchers using angle-resolved photoemission spectroscopy (ARPES) have now produced the first direct evidence of massless Dirac fermions in graphite coexisting with quasiparticles of finite effective mass and defect-induced localized states.

228

Nature and Origin of the Cuprate Pseudogap  

NLE Websites -- All DOE Office Websites (Extended Search)

Nature and Origin of the Cuprate Pseudogap Print Nature and Origin of the Cuprate Pseudogap Print The workings of high-temperature superconductive (HTSC) materials are a mystery wrapped in an enigma. However, a team of researchers from the ALS, Brookhaven National Laboratory, and Cornell University has taken a major step in understanding part of this mystery-the nature and origin of the pseudogap. Using angle-resolved photoemission spectroscopy (ARPES) and scanning tunneling microscopy (STM), they have determined the electronic structure of La2-xBaxCuO4 (LBCO), a unique system in which superconductivity is strongly suppressed and static spin and charge orders develop near a doping level of x = 1/8. Getting Wired with HTSCs Ever since the discovery of high-temperature superconductors (HTSCs), researchers have wrestled with not only theory, but application. One of the main problems is critical temperature, the temperature below which electrons can move within a material without resistance. The first HTSCs conducted electricity at 35 kelvin (K). Researchers keep pushing this limit, and today HTSCs can superconduct at 138 K. However, until a material is found that superconducts above 300 K, a cooling system is required.

229

Superconducting Topological Insulators  

NLE Websites -- All DOE Office Websites (Extended Search)

Superconducting Topological Insulators Print Superconducting Topological Insulators Print Three-dimensional topological insulators (TIs), discovered experimentally in 2007-2009 by a Princeton-ALS collaboration, are a promising platform for developing the next generation of electronics. Electrons within one nanometer of a TI's surface move at high speeds in a "light-like" fashion. The quantum interactions that generate these electronic states cause individual electrons to be spin polarized even at room temperature and to strongly resist scattering from defects, naturally achieving some of the most desirable traits for computing components and next-generation "spintronics" technologies. More recent angle-resolved photoemission spectroscopy (ARPES) studies performed at ALS Beamlines 10.0.1 and 12.0.1 by the same collaboration have paved a way for these novel material properties to be taken even further. Their studies showed that by doping the TI, bismuth selenide, with copper, it's possible to make the topologically ordered electrons superconducting, dropping electrical resistance in the surface states all the way to zero.

230

Surprising Quasiparticle Interactions in Graphene  

NLE Websites -- All DOE Office Websites (Extended Search)

Surprising Quasiparticle Surprising Quasiparticle Interactions in Graphene Surprising Quasiparticle Interactions in Graphene Print Wednesday, 31 October 2007 00:00 Until now, the world's electronics have been dominated by silicon, whose properties, while excellent, significantly limit the size and power consumption of today's computer chips. In order to develop ever smaller and more efficient devices, scientists have turned their attention to carbon, which can be formed into nanostructures like nanotubes, whose properties can be tuned from metallic to semiconducting. However, using carbon nanotubes for complex circuits is nearly impossible because their location and functionality in devices cannot be controlled at will, making them a poor substitute for silicon. Graphene, however, does not have these limitations. This single sheet of carbon atoms that is the building block of carbon nanotubes, C60 molecules, and graphite turns out to have similar functionality but with the added benefit that it can be grown with conventional methods and patterned into devices. Now, a group of scientists from Germany and the ALS, using angle-resolved photoemission spectroscopy (ARPES) at ALS Beamine 7.0.1, have succeeded in making the first measurement of the carrier lifetime in graphene over a wide energy scale and have found surprising new interactions that suggest new kinds of devices.

231

Controlling Graphene's Electronic Structure  

NLE Websites -- All DOE Office Websites (Extended Search)

Controlling Graphene's Electronic Structure Print Controlling Graphene's Electronic Structure Print Graphene, because of its unusual electron properties, reduced dimensionality, and scale, has enormous potential for use in ultrafast electronic transistors. It exhibits high conductivity and an anomalous quantum Hall effect (a phenomenon exhibited by certain semiconductor devices at low temperatures and high magnetic fields). Among its novel properties, graphene's electrical charge carriers (electrons and holes) move through a solid with effectively zero mass and constant velocity, like photons. Graphene's intrinsically low scattering rate from defects implies the possibility of a new kind of electronics based on the manipulation of electrons as waves rather than particles. The primary technical difficulty has been controlling the transport of electrical charge carriers through the sheet. This area of research is known as bandgap engineering. While bandgap engineering is the basis of semiconductor technology, it is only now being applied to graphene. Using angle-resolved photoemission spectroscopy (ARPES) at ALS Beamline 7.0.1, a team of scientists from the ALS and Germany characterized the electronic band structure and successfully controlled the gap between valence and conduction bands in a bilayer of graphene thin films deposited on a substrate of silicon carbide. This was done by doping one sheet with adsorbed potassium atoms, creating an asymmetry between the two layers.

232

Nature and Origin of the Cuprate Pseudogap  

NLE Websites -- All DOE Office Websites (Extended Search)

Nature and Origin of the Cuprate Pseudogap Print Nature and Origin of the Cuprate Pseudogap Print The workings of high-temperature superconductive (HTSC) materials are a mystery wrapped in an enigma. However, a team of researchers from the ALS, Brookhaven National Laboratory, and Cornell University has taken a major step in understanding part of this mystery-the nature and origin of the pseudogap. Using angle-resolved photoemission spectroscopy (ARPES) and scanning tunneling microscopy (STM), they have determined the electronic structure of La2-xBaxCuO4 (LBCO), a unique system in which superconductivity is strongly suppressed and static spin and charge orders develop near a doping level of x = 1/8. Getting Wired with HTSCs Ever since the discovery of high-temperature superconductors (HTSCs), researchers have wrestled with not only theory, but application. One of the main problems is critical temperature, the temperature below which electrons can move within a material without resistance. The first HTSCs conducted electricity at 35 kelvin (K). Researchers keep pushing this limit, and today HTSCs can superconduct at 138 K. However, until a material is found that superconducts above 300 K, a cooling system is required.

233

Nature and Origin of the Cuprate Pseudogap  

NLE Websites -- All DOE Office Websites (Extended Search)

Nature and Origin of the Cuprate Pseudogap Print Nature and Origin of the Cuprate Pseudogap Print The workings of high-temperature superconductive (HTSC) materials are a mystery wrapped in an enigma. However, a team of researchers from the ALS, Brookhaven National Laboratory, and Cornell University has taken a major step in understanding part of this mystery-the nature and origin of the pseudogap. Using angle-resolved photoemission spectroscopy (ARPES) and scanning tunneling microscopy (STM), they have determined the electronic structure of La2-xBaxCuO4 (LBCO), a unique system in which superconductivity is strongly suppressed and static spin and charge orders develop near a doping level of x = 1/8. Getting Wired with HTSCs Ever since the discovery of high-temperature superconductors (HTSCs), researchers have wrestled with not only theory, but application. One of the main problems is critical temperature, the temperature below which electrons can move within a material without resistance. The first HTSCs conducted electricity at 35 kelvin (K). Researchers keep pushing this limit, and today HTSCs can superconduct at 138 K. However, until a material is found that superconducts above 300 K, a cooling system is required.

234

BEAMLINE 5-4  

NLE Websites -- All DOE Office Websites (Extended Search)

5-4 5-4 CURRENT STATUS: Open SUPPORTED TECHNIQUES: Very High Energy Resolution; Photoemission Angle-Resolved Photoelectron Spectroscopy MAIN SCIENTIFIC DISCIPLINES: Materials % TIME GENERAL USE: 100% SCHEDULING: Proposal Submittal and Scheduling Procedures Current SPEAR and Beam Line Schedules SOURCE: 10-period undulator, maximum field 0.61 T BEAM LINE SPECIFICATIONS: energy range grating type resolution DE/E spot size flux angular acceptance focused 7-40 eV 1700 l/mm: 7-18 eV, E/DE > 10000 2800 l/mm: 16-32 eV, E/DE> 10000 3600 l/mm: 20-40 eV, E/DE> 10000 ≥1 x 10-4 0.5 x 0.6 mm2 ~1011 >1.5 mrad OPTICS: M0: horizontal deflecting, flat, water-cooled M1: vertical focusing 10:1, elliptically cylinder M3: horizontal refocusing 1:1, cylinder M4: vertical refocusing 1:1, cylinder

235

Superconducting Topological Insulators  

NLE Websites -- All DOE Office Websites (Extended Search)

Superconducting Topological Insulators Print Superconducting Topological Insulators Print Three-dimensional topological insulators (TIs), discovered experimentally in 2007-2009 by a Princeton-ALS collaboration, are a promising platform for developing the next generation of electronics. Electrons within one nanometer of a TI's surface move at high speeds in a "light-like" fashion. The quantum interactions that generate these electronic states cause individual electrons to be spin polarized even at room temperature and to strongly resist scattering from defects, naturally achieving some of the most desirable traits for computing components and next-generation "spintronics" technologies. More recent angle-resolved photoemission spectroscopy (ARPES) studies performed at ALS Beamlines 10.0.1 and 12.0.1 by the same collaboration have paved a way for these novel material properties to be taken even further. Their studies showed that by doping the TI, bismuth selenide, with copper, it's possible to make the topologically ordered electrons superconducting, dropping electrical resistance in the surface states all the way to zero.

236

Electron-State Hybridization in Heavy-Fermion Systems  

NLE Websites -- All DOE Office Websites (Extended Search)

Electron-State Hybridization in Heavy-Fermion Systems Print Electron-State Hybridization in Heavy-Fermion Systems Print Heavy-fermion systems are characterized by electrons with extremely large effective masses. The corresponding heavy-electron "quasiparticle" states are close to the Fermi energy and govern the thermodynamic, transport, and, in part, magnetic properties of these materials. In the case of rare-earth compounds, the quasiparticle states arise from the interactions (hybridization) of valence states with strongly localized 4f states. The question as to whether it is sufficient to treat the f states as localized impurities (single-impurity Anderson model) or whether the periodic crystal symmetry must be considered (periodic Anderson model) has been the subject of extensive debate. An international team of researchers from Germany, Ukraine, India, and the U.S. has performed angle-resolved photoemission spectroscopy (ARPES) studies of the heavy-fermion system YbIr2Si2. The results show a strong momentum (directional) dependence of the hybridization that clearly rules out the single-impurity model in favor of the lattice model.

237

ARPES Provides Direct Evidence of Spin-Wave Coupling  

NLE Websites -- All DOE Office Websites (Extended Search)

ARPES Provides Direct Evidence ARPES Provides Direct Evidence of Spin-Wave Coupling ARPES Provides Direct Evidence of Spin-Wave Coupling Print Wednesday, 30 March 2005 00:00 The electronic properties of a metal are determined by the dynamical behavior of its conduction electrons. Conventional band theory accounts for the interaction of the electrons with the static ion lattice. However, coupling to further microscopic degrees of freedom can alter the electron dynamics considerably. For example, "conventional" superconductivity emerges as a result of the electrons' interaction with lattice vibrations (phonons). In magnetic materials, coupling with spin waves (magnons) is also expected. Such interactions may contribute to high-temperature superconductivity in novel materials. Unfortunately, lattice vibrations and spin waves have similar energy scales, hindering detailed study. Researchers have taken a new approach in analyzing the electron bands of ferromagnetic iron. Angle-resolved photoemission spectroscopy (ARPES) provides direct spectroscopic evidence of altered electron mass and energy (quasiparticle formation) in a magnetic solid due to coupling with spin waves.

238

Electron-State Hybridization in Heavy-Fermion Systems  

NLE Websites -- All DOE Office Websites (Extended Search)

Electron-State Hybridization in Heavy-Fermion Systems Print Electron-State Hybridization in Heavy-Fermion Systems Print Heavy-fermion systems are characterized by electrons with extremely large effective masses. The corresponding heavy-electron "quasiparticle" states are close to the Fermi energy and govern the thermodynamic, transport, and, in part, magnetic properties of these materials. In the case of rare-earth compounds, the quasiparticle states arise from the interactions (hybridization) of valence states with strongly localized 4f states. The question as to whether it is sufficient to treat the f states as localized impurities (single-impurity Anderson model) or whether the periodic crystal symmetry must be considered (periodic Anderson model) has been the subject of extensive debate. An international team of researchers from Germany, Ukraine, India, and the U.S. has performed angle-resolved photoemission spectroscopy (ARPES) studies of the heavy-fermion system YbIr2Si2. The results show a strong momentum (directional) dependence of the hybridization that clearly rules out the single-impurity model in favor of the lattice model.

239

First Direct Evidence of Dirac Fermions in Graphite  

NLE Websites -- All DOE Office Websites (Extended Search)

Direct Evidence of Dirac Direct Evidence of Dirac Fermions in Graphite First Direct Evidence of Dirac Fermions in Graphite Print Wednesday, 27 June 2007 00:00 The recent surge of interest in the electronic properties of graphene-that is, isolated layers of graphite just one atomic layer thick-has largely been driven by the discovery that electron mobility in graphene is ten times higher than in commercial-grade silicon, raising the possibility of high-efficiency, low-power, carbon-based electronics. Scientists attribute graphene's surprising current capacity (as well as a number of even stranger phenomena) to the presence of charge carriers that behave as if they are massless, "relativistic" quasiparticles called Dirac fermions. Harnessing these quasiparticles in real-world carbon-based devices, however, requires a deeper knowledge of their behavior under less-than-ideal circumstances, such as around defects, at edges, or in three dimensions-in other words, in graphite. At the ALS, a team of researchers using angle-resolved photoemission spectroscopy (ARPES) have now produced the first direct evidence of massless Dirac fermions in graphite coexisting with quasiparticles of finite effective mass and defect-induced localized states.

240

Electron-State Hybridization in Heavy-Fermion Systems  

NLE Websites -- All DOE Office Websites (Extended Search)

Electron-State Hybridization in Electron-State Hybridization in Heavy-Fermion Systems Electron-State Hybridization in Heavy-Fermion Systems Print Wednesday, 27 September 2006 00:00 Heavy-fermion systems are characterized by electrons with extremely large effective masses. The corresponding heavy-electron "quasiparticle" states are close to the Fermi energy and govern the thermodynamic, transport, and, in part, magnetic properties of these materials. In the case of rare-earth compounds, the quasiparticle states arise from the interactions (hybridization) of valence states with strongly localized 4f states. The question as to whether it is sufficient to treat the f states as localized impurities (single-impurity Anderson model) or whether the periodic crystal symmetry must be considered (periodic Anderson model) has been the subject of extensive debate. An international team of researchers from Germany, Ukraine, India, and the U.S. has performed angle-resolved photoemission spectroscopy (ARPES) studies of the heavy-fermion system YbIr2Si2. The results show a strong momentum (directional) dependence of the hybridization that clearly rules out the single-impurity model in favor of the lattice model.

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241

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

SciTech Connect

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

242

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

243

Ethylene adsorbed on Ni(110): An experimental and theoretical determination of the two-dimensional band structure  

Science Journals Connector (OSTI)

We have investigated the saturated ethylene layer on Ni(110) by low-energy electron diffraction (LEED), angle-resolved ultraviolet photoemission spectroscopy (ARUPS), and near-edge x-ray-absorption fine structure (NEXAFS). This layer exhibits a c(2×4) LEED pattern that corresponds to a structure containing two adsorbates per primitive unit cell. The ethylene molecules are adsorbed with the molecular plane parallel to the surface and the C-C axis preferentially aligned along the [11¯0] direction of the substrate, as is independently determined from the ARUPS and NEXAFS experiments. The two-dimensional (2D) adsorbate band structure is determined from the ARUPS spectra at various photon energies. Except for the ? orbital, all ethylene-derived bands show significant dispersion (up to 2 eV), but no splitting as would be expected for a structure with two molecules per unit cell. The experimentally determined band structure is reproduced in all details by extended-Hückel-theory calculations for an unsupported ethylene layer. The structural model derived from LEED, ARUPS, and NEXAFS is confirmed both by force field and by the 2D band-structure calculations. This indicates that the adsorbate-adsorbate interactions are essentially decoupled from the adsorbate-substrate interaction, that is responsible for the chemisorption bond.

M. Weinelt; W. Huber; P. Zebisch; H.-P. Steinrück; B. Reichert; U. Birkenheuer; N. Rösch

1992-07-15T23:59:59.000Z

244

Electronic Reconstruction through the Structural and Magnetic Transitions in Detwinned NaFeAs  

SciTech Connect

We use angle-resolved photoemission spectroscopy to study twinned and detwinned iron pnictide compound NaFeAs. Distinct signatures of electronic reconstruction are observed to occur at the structural (T{sub S}) and magnetic (T{sub SDW}) transitions. At T{sub S}, C{sub 4} rotational symmetry is broken in the form of an anisotropic shift of the orthogonal d{sub xz} and d{sub yz} bands. The magnitude of this orbital anisotropy rapidly develops to near completion upon approaching T{sub SDW}, at which temperature band folding occurs via the antiferromagnetic ordering wave vector. Interestingly, the anisotropic band shift onsetting at T{sub S} develops in such a way to enhance the nesting conditions in the C{sub 2} symmetric state, hence is intimately correlated with the long range collinear AFM order. Furthermore, the similar behaviors of the electronic reconstruction in NaFeAs and Ba(Fe{sub 1-x}Co{sub x}){sub 2}As{sub 2} suggests that this rapid development of large orbital anisotropy between T{sub S} and T{sub SDW} is likely a general feature of the electronic nematic phase in the iron pnictides, and the associated orbital fluctuations may play an important role in determining the ground state properties.

Yi, M.; Lu, D.H.; Moore, R.G.; Kihou, K; Lee, C-H; Iyo, A.; Eisaki, H.; Yoshida, T; Fujimori, A; Shen, Z-X

2012-05-25T23:59:59.000Z

245

Tuning of the Metal-Insulator Transition via Alkali Adsorption  

NLE Websites -- All DOE Office Websites (Extended Search)

Tuning of the Metal-Insulator Tuning of the Metal-Insulator Transition via Alkali Adsorption Tuning of the Metal-Insulator Transition via Alkali Adsorption Print Wednesday, 29 March 2006 00:00 Turning a material from an insulator to a metal, or vice versa, by light irradiation, exposure to electric or magnetic fields, or applying small changes in temperature, pressure, or doping-such intriguing control of a material's electronic properties is possible by exploiting strongly interacting or "correlated" electrons. Now a team of researchers from the University of Kiel in Germany and the ALS has found a novel, surprising way to continuously transform a layered metallic transition-metal compound, TaS2, into an insulator. Using angle-resolved photoemission spectroscopy (ARPES), they have demonstrated that adsorption of alkali atoms onto this material's surface gradually makes it more insulating, although in general, alkali adsorption should lead to more metallic behavior, as alkali atoms easily give away their loosely bound outermost electron.

246

Electron-State Hybridization in Heavy-Fermion Systems  

NLE Websites -- All DOE Office Websites (Extended Search)

Electron-State Hybridization in Heavy-Fermion Systems Print Electron-State Hybridization in Heavy-Fermion Systems Print Heavy-fermion systems are characterized by electrons with extremely large effective masses. The corresponding heavy-electron "quasiparticle" states are close to the Fermi energy and govern the thermodynamic, transport, and, in part, magnetic properties of these materials. In the case of rare-earth compounds, the quasiparticle states arise from the interactions (hybridization) of valence states with strongly localized 4f states. The question as to whether it is sufficient to treat the f states as localized impurities (single-impurity Anderson model) or whether the periodic crystal symmetry must be considered (periodic Anderson model) has been the subject of extensive debate. An international team of researchers from Germany, Ukraine, India, and the U.S. has performed angle-resolved photoemission spectroscopy (ARPES) studies of the heavy-fermion system YbIr2Si2. The results show a strong momentum (directional) dependence of the hybridization that clearly rules out the single-impurity model in favor of the lattice model.

247

Stability of graphene band structures against an external periodic perturbation: Na on graphene  

Science Journals Connector (OSTI)

The electronic structure of Na-adsorbed graphenes formed on the 6H-SiC(0001) substrate was studied using angle-resolved photoemission spectroscopy with synchrotron photons and ab initio pseudopotential calculations. It was found that the band of the graphenes sensitively changes upon Na adsorption especially at low temperature. With increasing Na dose, the ? band appears to be quickly diffused into the background at 85 K whereas it becomes significantly enhanced with its spectral intensity at room temperature (RT). A new parabolic band centered at k?1.15?Å?1 also forms near Fermi energy with Na at 85 K while no such band was observed at RT. Such changes in the band structure are found to be reversible with temperature. The changes in the ? band of graphene are mainly driven by the Na-induced potential especially at low temperature where the potential becomes periodic due to the crystallized Na overlayer. The new parabolic band turns out to be the ? band of the underlying buffer layer partially filled by the charge transfer from Na adatoms. The increase in the hopping rate of Na adatoms at RT by 5 orders of magnitude prevents such a charge transfer, explaining the absence of the new band at RT.

C. G. Hwang; S. Y. Shin; Seon-Myeong Choi; N. D. Kim; S. H. Uhm; H. S. Kim; C. C. Hwang; D. Y. Noh; Seung-Hoon Jhi; J. W. Chung

2009-03-27T23:59:59.000Z

248

Atomic Spectroscopy and Separated Isotopes  

Science Journals Connector (OSTI)

The advantages in the use of separated isotopes in atomic spectroscopy for the determination of nuclear momentsI ? Q and for studies of the isotope-shift phenomena are discussed. Illustrations of spectra are given for mercury uranium and samarium. In addition a summary is given of twenty-two so-called problem nuclei i.e. those naturally occurring isotopes for which the nuclear moments are completely uncertain. Concluding remarks are made on such problems as the evaluation of the absolute magnitude of isotope shifts the role of “forbidden transitions” in isotope spectra and the potential future value of spectro-isotopic assay techniques.

J. R. McNally Jr.

1952-01-01T23:59:59.000Z

249

1 - Fundamentals of optical spectroscopy  

Science Journals Connector (OSTI)

Abstract: This chapter discusses the electronic, vibrational, and rotational spectroscopy of atoms and molecules, and the relationship between the concentration of a species and its spectral intensities. The different types of radiative transitions and spectral broadening mechanisms are discussed. A brief review of energy levels and selection rules for radiative transitions and hence allowed spectroscopic transitions for both atoms and molecules are presented. The determination of the plasma temperature and the temperatures of molecular degrees of freedom from spectroscopic observations is addressed. The effect of spectral congestion is illustrated through the display of simulated spectra at different resolutions.

P.J. Dagdigian

2014-01-01T23:59:59.000Z

250

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

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

251

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...

252

Terahertz spectroscopy for quantifying refined oil mixtures  

Science Journals Connector (OSTI)

In this paper, the absorption coefficient spectra of samples prepared as mixtures of gasoline and diesel in different proportions are obtained by terahertz time-domain spectroscopy. To...

Li, Yi-nan; Li, Jian; Zeng, Zhou-mo; Li, Jie; Tian, Zhen; Wang, Wei-kui

2012-01-01T23:59:59.000Z

253

RIJKSUNIVERSITEIT GRONINGEN Mid-Infrared Spectroscopy of  

E-Print Network (OSTI)

RIJKSUNIVERSITEIT GRONINGEN Mid-Infrared Spectroscopy of Dusty Galactic Nuclei PROEFSCHRIFT ter verkrijging van het doctoraat in de Wiskunde en Natuurwetenschappen aan de Rijksuniversiteit Groningen op

Spoon, Henrik

254

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

255

Nonlinear Spectroscopy of Trapped Ions  

E-Print Network (OSTI)

Nonlinear spectroscopy employs a series of laser pulses to interrogate dynamics in large interacting many-body systems, and has become a highly successful method for experiments in chemical physics. Current quantum optical experiments approach system sizes and levels of complexity which require the development of efficient techniques to assess spectral and dynamical features with scalable experimental overhead. However, established methods from optical spectroscopy of macroscopic ensembles cannot be applied straightforwardly to few-atom systems. Based on the ideas proposed in [M. Gessner et al. New J. Phys. 16 092001 (2014)], we develop a diagrammatic approach to construct nonlinear measurement protocols for controlled quantum systems and discuss experimental implementations with trapped ion technology in detail. These methods in combination with distinct features of ultra-cold matter systems allow us to monitor and analyze excitation dynamics in both the electronic and vibrational degrees of freedom. They are independent of system size, and can therefore reliably probe systems where, e.g., quantum state tomography becomes prohibitively expensive. We propose signals that can probe steady state currents, detect the influence of anharmonicities on phonon transport, and identify signatures of chaotic dynamics near a quantum phase transition in an Ising-type spin chain.

Frank Schlawin; Manuel Gessner; Shaul Mukamel; Andreas Buchleitner

2014-10-07T23:59:59.000Z

256

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

NLE Websites -- All DOE Office Websites (Extended Search)

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

257

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

NLE Websites -- All DOE Office Websites (Extended Search)

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

258

VUV spectroscopy of water under cellular conditions  

Science Journals Connector (OSTI)

......Beer-Lambert calculation. RESULTS AND...is left in its electronic ground state...42 eV) and does not appear to...shift in the electronic state spectroscopy...films. In: Handbook of Surfaces and...study of the electronic state spectroscopy...gaseous water and does not show the......

R. Mota; R. Parafita; M. J. P. Maneira; N. J. Mason; G. Garcia; P. A. Ribeiro; M. Raposo; P. Limão-Vieira

2006-12-01T23:59:59.000Z

259

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.

260

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

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

Spectroscopy of 215Rn86  

SciTech Connect

The yrast level structure of 215,216Rn has been studied using in beam spectroscopy {alpha} - {gamma} - {gamma} coincidence techniques mainly through the 207Pb(18O, 2{alpha}2n) and 208Pb(18O, 2{alpha}2n) reactions in the 91-93 MeV energy range, using the 8{pi} GASP-ISIS spectrometer at Legnaro. The obtained low lying level scheme of 215Rn does not exhibit the alternating parity structure observed in their heavier known isotones 216Fr, 217Ra and 218Ac. The level scheme of 216Rn resulting from this study shows >From this result, the lightest nucleus showing evidence for reflection asymmetry is 216Fr defining one lowest-mass corner for this kind of phenomenon as N{>=}129 and Z{>=}87.

Debray, M. E. [Departamento de Fisica, Comision Nacional de Energia Atomica, 1429 Buenos Aires (Argentina); Escuela de Ciencia y Tecnologia, Universidad de San Martin, 1650 San Martin, Buenos Aires (Argentina); Davidson, M.; Davidson, J.; Hojman, D. [Departamento de Fisica, Comision Nacional de Energia Atomica, 1429 Buenos Aires (Argentina); CONICET, 1033 Buenos Aires (Argentina); Kreiner, A. J.; Cardona, M. A. [Departamento de Fisica, Comision Nacional de Energia Atomica, 1429 Buenos Aires (Argentina); Escuela de Ciencia y Tecnologia, Universidad de San Martin, 1650 San Martin, Buenos Aires (Argentina); CONICET, 1033 Buenos Aires (Argentina); Lenzi, S. [INFN, Laboratori Nazionali di Legnaro, 35020 Legnaro (Italy); Napoli, D. [Dipartimento di Fisica, Sezione di Padova, Padova (Italy)

2007-02-12T23:59:59.000Z

262

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

263

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

264

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

265

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

NLE Websites -- All DOE Office Websites (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...

266

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

NLE Websites -- All DOE Office Websites (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...

267

Polarization-enhanced absorption spectroscopy for laser stabilization  

Science Journals Connector (OSTI)

We demonstrate a variation of pump-probe spectroscopy that is particularly useful for laser frequency stabilization. The polarization-enhanced absorption spectroscopy (POLEAS) signal...

Kunz, Paul D; Heavner, Thomas P; Jefferts, Steven R

2013-01-01T23:59:59.000Z

268

Operando Raman and Theoretical Vibration Spectroscopy of Non...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Operando Raman and Theoretical Vibration Spectroscopy of Non-PGM Catalysts Operando Raman and Theoretical Vibration Spectroscopy of Non-PGM Catalysts Presentation about...

269

High Resolution and Low-Temperature Photoelectron Spectroscopy...  

NLE Websites -- All DOE Office Websites (Extended Search)

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

270

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

NLE Websites -- All DOE Office Websites (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...

271

Infrared Spectroscopy and Optical Constants of Porous Amorphous...  

NLE Websites -- All DOE Office Websites (Extended Search)

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

272

Laser photoelectron spectroscopy of ions  

SciTech Connect

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

273

PAC spectroscopy of electronic ceramics  

SciTech Connect

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

274

PAC spectroscopy of electronic ceramics  

SciTech Connect

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

275

INSTRUMENTATION FOR FAR INFRARED SPECTROSCOPY.  

SciTech Connect

Fourier transform spectrometers developed in three distinct spectral regions in the early 1960s. Pierre Connes and his coworkers in France developed remarkably sophisticated step-scan interferometers that permitted near-infrared spectra to be measured with a resolution of better than 0.0 1 cm{sup {minus}1}. These instruments may be considered the forerunners of the step-scan interferometers made by Bruker, Bio-Rad (Cambridge, MA, USA) and Nicolet although their principal application was in the field of astronomy. Low-resolution rapid-scanning interferometers were developed by Larry Mertz and his colleagues at Block Engineering (Cambridge, MA, USA) for remote sensing. Nonetheless, the FT-IR spectrometers that are so prevalent in chemical laboratories today are direct descendants of these instruments. The interferometers that were developed for far-infrared spectrometry in Gebbie's laboratory ,have had no commercial counterparts for at least 15 years. However, it could be argued that these instruments did as much to demonstrate the power of Fourier transform spectroscopy to the chemical community as any of the instruments developed for mid- and near-infrared spectrometry. Their performance was every bit as good as today's rapid-scanning interferometers. However, the market for these instruments is so small today that it has proved more lucrative to modify rapid-scanning interferometers that were originally designed for mid-infrared spectrometry than to compete with these instruments with slow continuous scan or step-scan interferometers.

GRIFFITHS, P.R.; HOMES, C.

2001-05-04T23:59:59.000Z

276

Soft X-Ray and Vacuum Ultraviolet Based Spectroscopy of the Actinides  

SciTech Connect

The subjects of discussion included: VUV photoelectron spectroscopy, X-ray photoelectron spectroscopy, Synchrotron-radiation-based photoelectron spectroscopy, Soft x-ray absorption spectroscopy, Soft x-ray emission spectroscopy, Inverse photoelectron spectroscopy, Bremstrahlung Isochromat Spectroscopy, Low energy IPES, Resonant inverse photoelectron spectroscopy.

Tobin, J G

2011-03-17T23:59:59.000Z

277

Instrument Series: Spectroscopy and Diffraction XPS Imaging  

NLE Websites -- All DOE Office Websites (Extended Search)

XPS Imaging XPS Imaging The X-ray photoelectron spectroscopy (XPS) imaging system provides fast, quantitative, real-time parallel imaging with highest resolution spectroscopy at all analysis areas. In addition, the system is equipped with temperature programmed desorption (TPD), ultraviolet photoelectron spectroscopy (UPS), ion scattering spectroscopy (ISS), a cluster/Ar + ion gun, and a five-axis automated stage with variable temperature sample environment at the analysis chamber. The system is also integrated with a radial distribution chamber (RDC), a full-size glove box, and a cold-stage at the sample introduction for air-sensitive, liquid-semisolid, biological and environmental sample transfers. In addition, the RDC has a simple sample transfer mechanism to the

278

Quantitative Elemental Analyses by Plasma Emission Spectroscopy  

Science Journals Connector (OSTI)

...Elemental Analyses by Plasma Emission Spectroscopy...Argon-supported inductively coupled plasmas operated at atmospheric pressures are excellent...HIGH-FREQUENCY ARGON PLASMA FOR OPTICAL EMISSION...EXPERIMENTAL-STUDY OF A 1-KW, 50-MHZ RF INDUCTIVELY COUPLED...

Velmer A. Fassel

1978-10-13T23:59:59.000Z

279

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

280

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

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

Quantitative Elemental Analyses by Plasma Emission Spectroscopy  

Science Journals Connector (OSTI)

...Elemental Analyses by Plasma Emission Spectroscopy...inductively coupled plasmas operated at atmospheric...INDUCTIVELY-COUPLED HIGH-FREQUENCY ARGON PLASMA FOR OPTICAL EMISSION...1-KW, 50-MHZ RF INDUCTIVELY COUPLED...STUDIES OF A RADIO-FREQUENCY INDUCTIVELY COUPLED...

Velmer A. Fassel

1978-10-13T23:59:59.000Z

282

Microfluidic devices for terahertz spectroscopy of biomolecules  

E-Print Network (OSTI)

, J. Hesler, and A.C. Samuels, "THz-spectroscopy of biological molecules," J. Bio. Phys. 29, 89/water systems by compact sensor chips," Appl. Phys. Lett. 89, 041114 (2006). 10. T. Baras, T. Kleine

Afshari, Ehsan

283

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

284

Theory and Applications of NMR Spectroscopy Arthur S. Edison  

E-Print Network (OSTI)

constructed from combinations of: "Protein NMR spectroscopy: Principles and Practice" Cavanagh, Fairbrother

Collins, Gary S.

285

Ultrafast Spectroscopy of Warm Dense Matter  

NLE Websites -- All DOE Office Websites (Extended Search)

Ultrafast Spectroscopy of Warm Dense Matter Print Ultrafast Spectroscopy of Warm Dense Matter Print Being neither solid, liquid, gas, nor plasma, warm dense matter (WDM) occupies a no man's land in the map of material phases. Its temperature can range between that of planetary cores (tens of thousands K) to that of stellar cores (hundreds of thousands K). Not only is it prevalent throughout the universe, it is relevant to inertial confinement fusion (ICF) and material performance under extreme conditions. However, because of its extreme temperatures and pressures, WDM tends to be drastically transient and thus difficult to study in the laboratory. Now, researchers have set up ultrafast x-ray absorption spectroscopy at the ALS to measure the electronic structure of WDMs, demonstrating that fast-changing electron temperatures of matter under extreme conditions can be determined with picosecond resolution.

286

Spectroscopy and atomic force microscopy of biomass  

NLE Websites -- All DOE Office Websites (Extended Search)

Spectroscopy Spectroscopy and atomic force microscopy of biomass L. Tetard a,b , A. Passian a,b,n , R.H. Farahi a , U.C. Kalluri c , B.H. Davison c , T. Thundat a,b a Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA b Department of Physics, University of Tennessee, Knoxville, TN 37996, USA c Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA a r t i c l e i n f o Keywords: Atomic force microscopy Spectroscopy Plant cells Biomass Nanomechanics a b s t r a c t Scanning probe microscopy has emerged as a powerful approach to a broader understanding of the molecular architecture of cell walls, which may shed light on the challenge of efficient cellulosic ethanol production. We have obtained preliminary images of both Populus and switchgrass samples using atomic force microscopy (AFM). The results show distinctive features that are shared by switchgrass

287

Spectroscopy of element 115 decay chains  

SciTech Connect

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

288

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

289

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

290

Laser spectroscopy and dynamics of transient species  

SciTech Connect

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

291

Nanoscale Spectroscopy and Nanotechnology 8 Scientific Program  

E-Print Network (OSTI)

1 Nanoscale Spectroscopy and Nanotechnology 8 Scientific Program Gleacher Center Chicago, USA #12 Materials, Argonne National Laboratory, Department of Medicine, The University of Chicago USA. (Invited, and Dept. of Medicine, University of Illinois, Chicago, USA. Fabrication and characterization of smart CNT

Kemner, Ken

292

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

293

Beam-Foil Spectroscopy - Quo Vadis?  

SciTech Connect

Beam-foil spectroscopy after 45 years: what has been realized of the promises, what is the state of the art, what is the status of the field, what present atomic physics problems should the technique be applied to, where can it be done? Will it be done? Beam-foil spectroscopy and its sibling techniques have been outstandingly productive tools of atomic physics, providing both important data and insight. For some forty years, the developments have led to improvements in working range and reliability, and catalogues of desirable further measurements can be formulated. However, most of the key persons who have carried out and directed much of the development effort are nearing retirement, and with them the leading facilities. it is thus not likely that many of the desirable BFS projects discussed will presently be pursued. High-Z element, high-charge state spectroscopy and some specific long-lived level lifetime measurements will, however, be taken over by electron beam ion traps, and heavy-ion storage rings will contribute some important benchmark measurements on electric-dipole forbidden or hyperfine-induced transitions. Beam-foil spectroscopy can still be expected to solve a number of interesting atomic physics questions, but as a technique, at present, it has dropped from fashion and support.

Trabert, E

2008-05-26T23:59:59.000Z

294

Spectroscopy and decays of charm and bottom  

SciTech Connect

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

295

Single molecule spectroscopy of tetrahedral oligophenylenevinylene molecules  

E-Print Network (OSTI)

Single molecule spectroscopy of tetrahedral oligophenylenevinylene molecules Melissa A. Summers form 17 July 2002 Abstract We probe the fluorescence from single molecules of a new class molecules and compare these signals with the fluorescence from single arm molecules. Our results show

Buratto, Steve

296

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

297

Dirac Charge Dynamcs in Graphene by Infrared Spectroscopy  

NLE Websites -- All DOE Office Websites (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...

298

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

299

Single-molecule reactions and spectroscopy via vibrational excitation  

Science Journals Connector (OSTI)

...J. Kelly and R. E. Palmer Single-molecule reactions and spectroscopy via...Inelastic Tunnelling|Vibration|Single Molecule|Scanning Tunnelling Microscopy (Stm)| Single-molecule reactions and spectroscopy via...

2004-01-01T23:59:59.000Z

300

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...

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

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

302

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

NLE Websites -- All DOE Office Websites (Extended Search)

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

303

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

NLE Websites -- All DOE Office Websites (Extended Search)

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

304

Charge exchange recombination spectroscopy on fusion devices  

SciTech Connect

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

305

Raman spectroscopy study of selected uranophanes  

Science Journals Connector (OSTI)

Raman spectra at 298 and 77 K of three uranophane samples from different localities are described and interpreted. The spectra are sample dependent. U–O bond lengths in uranyls are calculated from the spectra and compared with the published data of single crystal structure and EXAFS spectroscopy. Hydrogen-bonding of water molecules and silanols is discussed and the ‘proton mobility’ in uranophane sheet crystal structure is assumed.

Ray L. Frost; Ji?í ?ejka; Matt L. Weier; Wayde N. Martens

2006-01-01T23:59:59.000Z

306

Observation of an intrinsic 5×5 reconstruction on the clean Si(111) surface  

Science Journals Connector (OSTI)

Low-temperature annealing of the cleaved Si(111)2×1 surface revealed the existence of an intrinsic 5×5 reconstruction on the clean Si(111) surface. The electronic structure of the Si(111)5×5 surface, obtained with angle-resolved photoemission, is almost identical to that of the 7×7 reconstruction. This is strong evidence that the 5×5 reconstruction is also of the dimer–adatom–stacking-fault (DAS)-type. The experimental observation of a 5×5 reconstruction supports recent theoretical results that the 7×7 and 5×5 DAS models are very close in total surface energy.

R. I. G. Uhrberg; E. Landemark; L. S. O. Johansson

1989-06-15T23:59:59.000Z

307

Surface localized states and the Fermi contour of Pd(001)  

Science Journals Connector (OSTI)

Angle-resolved photoemission measurements of the surface localized electronic states of the clean Pd(001) surface are presented. Several surface localized levels were observed, in qualitative agreement with an existing surface band-structure calculation. In particular, a state was observed which crosses the Fermi level (EF) near the X¯ point of the surface Brillouin zone. The segment of the Fermi contour derived from this crossing lies largely within a gap in the projected bulk Fermi surface and is parallel to the Brillouin-zone edge. The nesting properties of this segment of the Fermi contour suggest the possibility of a fairly strong electronic coupling to phonon excitations.

G. S. Elliott, K. E. Smith, and S. D. Kevan

1991-02-15T23:59:59.000Z

308

Geometry and Electronic Structure of Cl on the Cu {001} Surface  

Science Journals Connector (OSTI)

The atomic geometry of Cu{001}c(2×2)-Cl has been determined by surface extended x-ray-absorption fine structure to consist of a simple Cl overlayer in fourfold Cu hollows with a (2.37 ± 0.02)-Å bond length. With use of this geometry, self-consistent electronic structure calculations were performed and compared with angle-resolved photoemission data, giving excellent agreement for the position and dispersion of several Cl-induced surface states and resonances. These results have resolved previously reported discrepancies for the Ag{001}c(2×2)-Cl system.

P. H. Citrin, D. R. Hamann, L. F. Mattheiss, and J. E. Rowe

1982-12-06T23:59:59.000Z

309

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

SciTech Connect

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

310

Chemical Tuning of Metal-Semiconductor Interfaces  

Science Journals Connector (OSTI)

We report a study of the Schottky barrier for Pb films grown on Si surfaces terminated by various metals (Ag, In, Au, and Pb) to explore the atomic-scale physics of the interface barrier and a means to control the barrier height. Electronic confinement by the Schottky barrier results in quantum well states in the Pb films, which are measured by angle-resolved photoemission. The barrier height is determined from the atomic-layer-resolved energy levels and the line widths. A calculation based on the known interface chemistry and the electronegativity yields predicted barrier heights in good agreement with the experiment.

D. A. Ricci; T. Miller; T.-C. Chiang

2004-09-20T23:59:59.000Z

311

Hall effect in the marginal Fermi liquid regime of high-Tc superconductors  

Science Journals Connector (OSTI)

The detailed derivation of a theory for transport in quasi-two-dimensional metals, with small-angle elastic scattering and angle-independent inelastic scattering is presented. The transport equation is solved for a model Fermi surface representing a typical cuprate superconductor. Using the small-angle elastic and the inelastic scattering rates deduced from angle-resolved photoemission experiments, good quantitative agreement with the observed anomalous temperature dependence of the Hall angle in optimally doped cuprates is obtained, while the resistivity remains linear in temperature. The theory is also extended to the frequency-dependent complex Hall angle.

Elihu Abrahams and C. M. Varma

2003-09-04T23:59:59.000Z

312

Strongly three-dimensional electronic structure and Fermi surfaces of SrFe2(As0.65P0.35)2: Comparison with BaFe2(As1?xPx)2  

Science Journals Connector (OSTI)

The isovalent-substituted iron-pnictide superconductor SrFe2(As1?xPx)2 (x=0.35) has a slightly higher optimum critical temperature than the similar system BaFe2(As1?xPx)2, and its parent compound SrFe2As2 has a much higher Néel temperature than BaFe2As2. We have studied the band structure and the Fermi surfaces of optimally doped SrFe2(As1?xPx)2 by angle-resolved photoemission spectroscopy (ARPES). Three holelike Fermi surfaces (FSs) around (0,0) and two electronlike FSs around (?,?) have been observed as in the case of BaFe2(As1?xPx)2. Measurements with different photon energies have revealed that the outermost hole FS is more strongly warped along the kz direction than the corresponding one in BaFe(As1?xPx)2, and that the innermost one is an ellipsoidal pocket. The electron FSs are almost cylindrical, unlike the corrugated ones in BaFe(As1?xPx)2. A comparison of the ARPES data with a first-principles band-structure calculation revealed that the quasiparticle mass renormalization factors are different not only between bands of different orbital character, but also between the hole and electron FSs of the same orbital character. By examining the nesting conditions between the hole and electron FSs, we conclude that magnetic interactions between FeAs layers rather than FS nesting play an important role in stabilizing the antiferromagnetic order. The insensitivity of superconductivity to the FS nesting can be explained if only the dxy and/or dxz/yz orbitals are active in inducing superconductivity or if FS nesting is not important for superconductivity.

H. Suzuki; T. Kobayashi; S. Miyasaka; T. Yoshida; K. Okazaki; L. C. C. Ambolode; II; S. Ideta; M. Yi; M. Hashimoto; D. H. Lu; Z.-X. Shen; K. Ono; H. Kumigashira; S. Tajima; A. Fujimori

2014-05-30T23:59:59.000Z

313

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

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

314

Symmetry-Breaking Orbital Anisotropy Observed for Detwinned Ba(Fe1-xCox)2As2 above the Spin Density Wave Transition  

SciTech Connect

Nematicity, defined as broken rotational symmetry, has recently been observed in competing phases proximate to the superconducting phase in the cuprate high temperature superconductors. Similarly, the new iron-based high temperature superconductors exhibit a tetragonal to orthorhombic structural transition (i.e. a broken C{sub 4} symmetry) that either precedes or is coincident with a collinear spin density wave (SDW) transition in undoped parent compounds, and superconductivity arises when both transitions are suppressed via doping. Evidence for strong in-plane anisotropy in the SDW state in this family of compounds has been reported by neutron scattering, scanning tunneling microscopy, and transport measurements. Here we present an angle resolved photoemission spectroscopy study of detwinned single crystals of a representative family of electron-doped iron-arsenide superconductors, Ba(Fe{sub 1-x}Co{sub x}){sub 2}As{sub 2} in the underdoped region. The crystals were detwinned via application of in-plane uniaxial stress, enabling measurements of single domain electronic structure in the orthorhombic state. At low temperatures, our results clearly demonstrate an in-plane electronic anisotropy characterized by a large energy splitting of two orthogonal bands with dominant d{sub xz} and d{sub yz} character, which is consistent with anisotropy observed by other probes. For compositions x > 0, for which the structural transition (T{sub S}) precedes the magnetic transition (T{sub SDW}), an anisotropic splitting is observed to develop above T{sub SDW}, indicating that it is specifically associated with T{sub S}. For unstressed crystals, the band splitting is observed close to T{sub S}, whereas for stressed crystals the splitting is observed to considerably higher temperatures, revealing the presence of a surprisingly large in-plane nematic susceptibility in the electronic structure.

Yi, Ming

2011-08-19T23:59:59.000Z

315

Estimating radiological background using imaging spectroscopy  

SciTech Connect

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

316

Synchrotron-Radiation-Based Moessbauer Spectroscopy  

SciTech Connect

We have developed a new method that yields Moessbauer absorption spectra using synchrotron radiation (SR); this method is applicable for almost all Moessbauer nuclides including those that cannot be measured by previous methods using radioisotope (RI) sources. The Moessbauer spectrum of the 68.752 keV excited state of {sup 73}Ge, which cannot be measured using a RI source, was measured using SR. Our results show that this method can be used to perform advanced Moessbauer spectroscopy measurements owing to the excellent features of SR.

Seto, Makoto [Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan-gun, Osaka 590-04 (Japan); Japan Atomic Energy Agency, 1-1-1 Kouto, Mikazuki-cho, Sayo-gun, Hyogo 679-5148 (Japan); CREST, Japan Science and Technology Agency, Saitama 332-0012 (Japan); Masuda, Ryo; Mitsui, Takaya [Japan Atomic Energy Agency, 1-1-1 Kouto, Mikazuki-cho, Sayo-gun, Hyogo 679-5148 (Japan); CREST, Japan Science and Technology Agency, Saitama 332-0012 (Japan); Higashitaniguchi, Satoshi; Kitao, Shinji; Kobayashi, Yasuhiro [Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan-gun, Osaka 590-04 (Japan); CREST, Japan Science and Technology Agency, Saitama 332-0012 (Japan); Inaba, Chika [Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan-gun, Osaka 590-04 (Japan); Yoda, Yoshitaka [Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Mikazuki-cho, Sayo-gun, Hyogo 679-5198 (Japan); CREST, Japan Science and Technology Agency, Saitama 332-0012 (Japan)

2009-05-29T23:59:59.000Z

317

(Resonance ionization spectroscopy and its applications)  

SciTech Connect

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

318

In Situ NMR Spectroscopy of Combustion  

Science Journals Connector (OSTI)

In situ nuclear magnetic resonance spectroscopy (NMR) of high-temperature reactions is of potential value for the investigation of catalytic combustion and other high-temperature applications of catalysts such as partial oxidation of hydrocarbons and steam reforming. ... Two-dimensional (2D) studies of gas exchange within different heat zones of the combustion process provide valuable insights into the gas-phase dynamics. ... This may be the case at the high combustion temperatures, but neither experimental nor theoretical xenon chemical shift data is available in current literature for temperatures above 1000 K. ...

Satyanarayana Anala; Galina E. Pavlovskaya; Prakash Pichumani; Todd J. Dieken; Michael D. Olsen; Thomas Meersmann

2003-10-07T23:59:59.000Z

319

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

320

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

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

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

322

Controlling light at the nanoscale: imaging and spectroscopy...  

NLE Websites -- All DOE Office Websites (Extended Search)

materials with spatial resolution down to nanometer length scales for, e.g., advanced solar energy and fuel cell applications. The extension of conventional optical spectroscopy...

323

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

324

Source Apportionment of Wastewater Using Bayesian Analysis of Fluorescence Spectroscopy.  

E-Print Network (OSTI)

??This research uses Bayesian analysis of fluorescence spectroscopy results to determine if wastewater from the Heber Valley Special Service District (HVSSD) lagoons in Midway, UT… (more)

Blake, Daniel B.

2014-01-01T23:59:59.000Z

325

Chirped Laser Dispersion Spectroscopy with Directly Modulated Quantum Cascade Laser  

Science Journals Connector (OSTI)

A feasibility study of chirped laser dispersion spectroscopy (CLaDS) with utilizing direct modulation of a quantum cascade laser instead of external modulators is presented....

Hangauer, Andreas; Spinner, Georg; Nikodem, Michal; Wysocki, Gerard

326

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

327

XRMS: X-Ray Spectroscopy of Magnetic Solids  

NLE Websites -- All DOE Office Websites (Extended Search)

XRMS: X-Ray Spectroscopy of Magnetic Solids October 22-23, 2011 SLAC National Accelerator Laboratory, Menlo Park, CA More information...

328

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

329

Vibrational Raman Spectroscopy of High-temperature Superconductors  

E-Print Network (OSTI)

Vibrational Raman Spectroscopy of High-temperature Superconductors C. Thomsen and G. Kaczmarczyk after the discovery of high- critical-temperature Tc superconductors:2 while reports on Raman scattering Wiley & Sons Ltd, Chichester, 2002 #12;Vibrational Raman Spectroscopy of High-temperature

Nabben, Reinhard

330

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

331

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

332

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

333

New Results on Baryon Spectroscopy from MAMI  

SciTech Connect

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

334

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

335

Diamond based single molecule magnetic resonance spectroscopy  

E-Print Network (OSTI)

The detection of a nuclear spin in an individual molecule represents a key challenge in physics and biology whose solution has been pursued for many years. The small magnetic moment of a single nucleus and the unavoidable environmental noise present the key obstacles for its realization. Here, we demonstrate theoretically that a single nitrogen-vacancy (NV) center in diamond can be used to construct a nano-scale single molecule spectrometer that is capable of detecting the position and spin state of a single nucleus and can determine the distance and alignment of a nuclear or electron spin pair. The proposed device will find applications in single molecule spectroscopy in chemistry and biology, such as in determining protein structure or monitoring macromolecular motions and can thus provide a tool to help unravelling the microscopic mechanisms underlying bio-molecular function.

Jianming Cai; Fedor Jelezko; Martin B. Plenio; Alex Retzker

2011-12-23T23:59:59.000Z

336

Core Level Spectroscopies Surface Science and X-Ray Spectroscopy Group  

NLE Websites -- All DOE Office Websites (Extended Search)

Core Level Spectroscopy Creation and Decay of Core Holes Spectroscopic Techniques X-ray Photoelectron (XPS) X-ray Absorption (XAS) X-ray Emission (XES) Auger Electron (AES) Core holes are created by the ionization of a core electron in XPS and by excitation in XAS . The XPS and XAS final states are highly unstable and the core hole decays by non-radiant Auger relaxation (AES) or by radiant x-ray emission processes (XES). XPS and AES probe the unoccupied electronic stru cture, while XAS projects the unoccupied valence states of the system onto a particular atom. A brief description of the each of the different spectroscopies illustrated by schematic pictures of the creation and decay with data measured for N2 adsorbed on Ni(100) can be found by scrolling

337

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

SciTech Connect

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

338

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

339

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.

340

Cl chemisorption on the Ag(001) surface: Geometry and electronic structure  

Science Journals Connector (OSTI)

Simple overlayer and mixed-layer geometries are studied for the observed c(2×2) structure of atomic Cl adsorbed on the Ag(001) surface. A self-consistent, Gaussian, linear-combination-of-atomic-orbitals technique with a local exchange-correlation potential is used. Reference calculations are performed for bulk Ag, the clean Ag(001) surface, and an isolated c(2×2)Cl layer. The calculated total and partial density of states for the two geometries are compared with angle-integrated and angle-resolved photoemission experiments. The mixed-layer model gives close agreement with experiment while the overlayer model predicts a single Cl feature above the Ag d band, contrary to the photoemission data. Discrepancies between these calculations and a low-energy electron diffraction study of this system are discussed.

H. S. Greenside and D. R. Hamann

1981-05-15T23:59:59.000Z

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.


341

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

NLE Websites -- All DOE Office Websites (Extended Search)

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

342

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

343

A new high luminosity UHV orange type magnetic spectrometer used for depth selective Mössbauer spectroscopy  

Science Journals Connector (OSTI)

For Auger Electron Spectroscopy (AES) a combination with an electrostatic retardation field around the sample will provide an even higher resolution. For depth selective conversion electron Mössbauer spectroscopy...

B. Stahl; R. Gellert; G. Klingelhöfer…

1997-05-01T23:59:59.000Z

344

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

NLE Websites -- All DOE Office Websites (Extended Search)

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

345

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

346

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

NLE Websites -- All DOE Office Websites (Extended Search)

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

347

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

NLE Websites -- All DOE Office Websites (Extended Search)

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

348

E-Print Network 3.0 - astrophotonic spectroscopy defining Sample...  

NLE Websites -- All DOE Office Websites (Extended Search)

Summary: impedance spectroscopy technique to characterize supercapacitors. We define its metrology 7 and we present... to use two complementary methods: impedance spectroscopy...

349

E-Print Network 3.0 - annihilation lifetime spectroscopy Sample...  

NLE Websites -- All DOE Office Websites (Extended Search)

spectroscopy... us the information on the exciton lifetime and exciton coherence time. It is therefore needed... to perform micro-photoluminescence (PL) spectroscopy...

350

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

351

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

NLE Websites -- All DOE Office Websites (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...

352

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

NLE Websites -- All DOE Office Websites (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...

353

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

NLE Websites -- All DOE Office Websites (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...

354

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

SciTech Connect

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

355

Early optical spectroscopy of supernova 1987A  

SciTech Connect

CCD spectroscopy of SN 1987A from February 24-28, 1987 is presented. Spectra with 10 A resolution and signal-to-noise ratio is excess of 200, over a range 3900 A to 9000 A, are reduced to flux relative to the continuum at 8000 A. Spectra as a function of time and nightly difference spectra are obtained. Strong and broad hydrogen Balmer P-Cygni profiles, increasing in intensity with time, and H-alpha absorption velocity decreasing from 19,000 km/s are seen. H-alpha velocity componnents up to 31,000 km/s are found on February 25 UT. The He I feature at 5400 A disappears after February 26 and Ca II at 8200 A appears strongly after February 27. Spectra as a function of angular distance from SN 1987A are also obtained, showing the adjacent nebular emission of the LMC. There is no evidence for a circumstellar shell. These data are most consistent with an unusually low envelope mass progenitor. 30 references.

Tyson, J.A.; Boeshaar, P.C.

1987-09-01T23:59:59.000Z

356

Validating the Melusine Gamma Spectroscopy Tool  

SciTech Connect

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

357

Ionization photophysics and spectroscopy of dicyanoacetylene  

SciTech Connect

Photoionization of dicyanoacetylene was studied using synchrotron radiation over the excitation range 8–25 eV, with photoelectron-photoion coincidence techniques. The absolute ionization cross-section and detailed spectroscopic aspects of the parent ion were recorded. The adiabatic ionization energy of dicyanoacetylene was measured as 11.80 ± 0.01 eV. A detailed analysis of the cation spectroscopy involves new aspects and new assignments of the vibrational components to excitation of the quasi-degenerate A{sup 2}?{sub g}, B{sup 2}?{sub g}{sup +} states as well as the C{sup 2}?{sub u}{sup +} and D{sup 2}?{sub u} states of the cation. Some of the structured autoionization features observed in the 12.4–15 eV region of the total ion yield spectrum were assigned to vibrational components of valence shell transitions and to two previously unknown Rydberg series converging to the D{sup 2}?{sub u} state of C{sub 4}N{sub 2}{sup +}. The appearance energies of the fragment ions C{sub 4}N{sup +}, C{sub 3}N{sup +}, C{sub 4}{sup +}, C{sub 2}N{sup +}, and C{sub 2}{sup +} were measured and their heats of formation were determined and compared with existing literature values. Thermochemical calculations of the appearance potentials of these and other weaker ions were used to infer aspects of dissociative ionization pathways.

Leach, Sydney, E-mail: Sydney.Leach@obspm.fr, E-mail: Martin.Schwell@lisa.u-pec.fr; Champion, Norbert [LERMA UMR CNRS 8112, Observatoire de Paris-Meudon, 5 place Jules-Jansen, 92195 Meudon (France)] [LERMA UMR CNRS 8112, Observatoire de Paris-Meudon, 5 place Jules-Jansen, 92195 Meudon (France); Schwell, Martin, E-mail: Sydney.Leach@obspm.fr, E-mail: Martin.Schwell@lisa.u-pec.fr; Bénilan, Yves; Fray, Nicolas; Gazeau, Marie-Claire [LISA UMR CNRS 7583, Université Paris-Est Créteil and Université Paris Diderot, Institut Pierre Simon Laplace, 61 Avenue du Général de Gaulle, 94010 Créteil (France)] [LISA UMR CNRS 7583, Université Paris-Est Créteil and Université Paris Diderot, Institut Pierre Simon Laplace, 61 Avenue du Général de Gaulle, 94010 Créteil (France); Garcia, Gustavo A.; Gaie-Levrel, François [Synchrotron SOLEIL, L’Orme des Merisiers, St. Aubin, B.P. 48, 91192 Gif-sur-Yvette Cedex (France)] [Synchrotron SOLEIL, L’Orme des Merisiers, St. Aubin, B.P. 48, 91192 Gif-sur-Yvette Cedex (France); Guillemin, Jean-Claude [Institut des Sciences Chimiques de Rennes, Ecole Nationale Supérieure de Chimie de Rennes, CNRS UMR 6226, 11 Allée de Beaulieu, CS 50837, 35708 Rennes Cedex 7 (France)] [Institut des Sciences Chimiques de Rennes, Ecole Nationale Supérieure de Chimie de Rennes, CNRS UMR 6226, 11 Allée de Beaulieu, CS 50837, 35708 Rennes Cedex 7 (France)

2013-11-14T23:59:59.000Z

358

Introduction of coherence in astrophysical spectroscopy  

E-Print Network (OSTI)

By confusing the radiance of a single mode light beam, constant in a transparent medium, with the irradiance which decreases away from the source, Menzel purports to show that coherent interactions of light with the diluted media of astrophysics, are negligible. Therefore, to study the interaction of light with gases, astrophysicists use Monte Carlo computations which work to study nuclear systems, but not optics: optical modes which may be defined in inhomogeneous media or for the emissions of single atoms interact coherently with these systems: a unique formula represents, according to the sign of a parameter, absorption and coherent emission. The optical and spectroscopic properties of a very simple model, an extremely hot source in an isotropic cloud of pure, low pressure, initially cold, huge hydrogen cloud are studied using Planck's and Einstein's theories. The similarities of the images and the spectra of this simple model with astronomical observations, for instance of SNR1987A, Einstein cross, lyman break galaxies, quasars,... is so large that this model may be an elementary first step in the study of many astrophysical objects. Adaptations of the model to complex astrophysical systems could represent them using only the old, standard theories of physics commonly used in laser spectroscopy.

Jacques Moret-Bailly

2010-02-08T23:59:59.000Z

359

Spectroscopy of Hyades L dwarf candidates  

E-Print Network (OSTI)

We present the results of photometric, astrometric, and spectroscopic follow-up of L dwarf candidates identified in the Hyades cluster by Hogan et al. (2008). We obtained low-resolution optical spectroscopy with the OSIRIS spectrograph on the Gran Telescopio de Canarias for all 12 L dwarf candidates as well as new J-band imaging for a subsample of eight to confirm their proper motion. We also present mid-infrared photometry from the Wise Field Infrared Survey Explorer (WISE) for the Hyades L and T dwarf candidates and estimate their spectroscopic distances, effective temperatures, and masses. We confirm the cool nature of several L dwarf candidates and confirm astrometrically their membership, bridging the gap between the coolest M dwarfs and the two T dwarfs previously reported in the Hyades cluster. These members represent valuable spectral templates at an age of 625 Myr and slightly super solar metallicity (Fe/H=+0.13). We update the Hyades mass function across the hydrogen-burning limit and in the substel...

Lodieu, N; Bejar, V J S

2014-01-01T23:59:59.000Z

360

FRONTIER SYNCHROTRON INFRARED SPECTROSCOPY BEAMLINE UNDER EXTREME CONDITIONS (FIS)  

NLE Websites -- All DOE Office Websites (Extended Search)

FRONTIER SYNCHROTRON INFRARED SPECTROSCOPY FRONTIER SYNCHROTRON INFRARED SPECTROSCOPY BEAMLINE UNDER EXTREME CONDITIONS (FIS) Proposal Team: L. Carr 1 , D. Dolan 2 , R. Hemley 3 , S. Jacobson 4 , S. Karato 5 , Z. Liu 3 , W. Panero 6 , M. Pravica 7 , and T. Zhou 8 1 Brookhaven National Laboratory, 2 Sandia National Laboratories, 3 Carnegie Institution of Washington, 4 Northwestern University, 5 Yale University, 6 Ohio State University, 7 University of Nevada, 8 New Jersey Institute of Technology TECHNIQUES AND CAPABILITIES APPLICATIONS SPECIFIC PROJECTS / ADDITIONAL INFORMATION * TECHNIQUE(S): Fourier transform infrared spectroscopy; Raman and visible spectroscopy; Diamond anvil cell techniques for static high pressure; Gas-gun launchers for dynamic compression; Cryogenic techniques combined with DACs;

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

A Different Laboratory Tale: Fifty Years of Mössbauer Spectroscopy  

Science Journals Connector (OSTI)

I explore the fifty-year development of Mössbauer spectroscopy by focusing on three episodes in its development at Argonne National Laboratory: work by nuclear physicists using radioactive sources in the early...

Catherine Westfall

2006-05-01T23:59:59.000Z

362

Magneto-optical spectroscopy of metallic carbon nanotubes.  

E-Print Network (OSTI)

??Through polarization-dependent magneto-optical absorption spectroscopy, the magnetic susceptibility anisotropy for metallic single-walled carbon nanotubes has been extracted and found to be up to 4x greater… (more)

Searles, Thomas A., Jr

2010-01-01T23:59:59.000Z

363

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

364

The Application of IR Spectroscopy to the Investigation of Minerals  

Science Journals Connector (OSTI)

Traditionally, the application of IR spectroscopy in mineralogy is reduced to the determination of wavelengths or frequencies of discrete absorption maxima. These values are brought in correspondence with normal ...

Nikita V. Chukanov

2014-01-01T23:59:59.000Z

365

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

366

Dirac Charge Dynamcs in Graphene by Infrared Spectroscopy  

NLE Websites -- All DOE Office Websites (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...

367

Photoelectron Spectroscopy of Free Multiply Charged Keggin Anions...  

NLE Websites -- All DOE Office Websites (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,...

368

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.

369

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

370

Photoelectron Spectroscopy under Ambient Pressure and Temperature Conditions  

E-Print Network (OSTI)

than ~ 100 l/s in a typical UHV system, so this produces aof spectroscopy chamber p 0 = UHV…~ torr preparation chamberpumping system was capable of UHV performance and maintained

Ogletree, D. Frank

2009-01-01T23:59:59.000Z

371

Laser Spectroscopy and Optical Diagnostics of Combustion Processes  

Science Journals Connector (OSTI)

Tunable diode laser absorption spectroscopy of temperature and species (NO,H2O,CO,CO2,UHC) with applications in coal fired powerplants, gasifiers and IC engines. Wavelength modulation...

Hanson, Ronald K

372

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

373

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

374

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

375

Microsoft PowerPoint - SpectroscopyTechniques_XANES  

NLE Websites -- All DOE Office Websites (Extended Search)

Near Edge Spectroscopy (XANES) Near Edge Spectroscopy (XANES) XANES: XANES: * Element specific * Highly sensitive to bond angles, bond lengths, and the presence of adsorbates NEXAFS (Near Edge X-ray Absorption Fine Structure): * Synonymous with XANES but soft x-ray spectroscopy (< 1keV) * Fine structure within about 30 eV of the absorption edge EXAFS XANES / XRD C bi i S EXAFS-XANES / XRD Combination Spectroscopy * XAFS-XANES and XRD techniques give complementary information about the structure of materials. * XRD is effective in materials with medium- to long-range A typical XANES Spectrum XRD is effective in materials with medium to long range order while XAFS provides short-range information. *The simultaneous collection of the XRD and XAFS- XANES data in situ will allow

376

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

377

Book Review of Handbook of Molecular Force Spectroscopy  

Science Journals Connector (OSTI)

The measurement of forces at the molecular level is an active and exciting area of research that has found application in a diverse range of disciplines, including chemistry, biology, and physics. ... In conclusion, Noy’s Handbook of Molecular Force Spectroscopy is both a timely and useful summary of fundamental aspects of molecular force spectroscopy, and I believe it would make a worthwhile addition to any good scientific library. ...

Matthew F. Paige

2008-06-04T23:59:59.000Z

378

Vibrational Spectroscopy: Recent Developments to Revolutionize Forensic Science  

Science Journals Connector (OSTI)

Vibrational Spectroscopy: Recent Developments to Revolutionize Forensic Science ... The National Academy of Sciences published a report outlining the current state of forensic science in the US, including issues being faced and necessary changes (National Research Council: Washington, D.C., 2009). ... These qualities, along with their automated capabilities, make Raman and IR spectroscopy model techniques according to the requirements outlined by the National Academy of Sciences. ...

Claire K. Luber; Kyle C Doty; Justin Bueno; Lenka Halamkova; Igor K. Lednev

2014-11-10T23:59:59.000Z

379

Photoelectron spectroscopy as a tool of lignin chemistry  

SciTech Connect

Many efforts in systematic elucidation of lignin properties start from the properties of the lignin subunits. In this paper, the authors provide the vertical ionization potentials (IP) of a representative set of lignin model compound. Gas phase photoelectron spectroscopy enables them to determine ionization potentials and makes it possible to deduce the electron structure of molecules within the limitations of Koopman's theorem. They discuss reasons why photoelectron spectroscopy might be a valuable method for the study of lignin properties.

Shevchenko, S.M.; Zarubin, M.Y. (Leningrad Forest Technical Academy, 194018 Leningrad (SU))

1989-05-01T23:59:59.000Z

380

Nonlinear optical spectroscopy of diamond surfaces  

SciTech Connect

Second harmonic generation (SHG) and infrared-visible sum frequency generation (SFG) spectroscopies have been shown to be powerful and versatile for studying surfaces with submonolayer sensitivity. They have been used in this work to study bare diamond surfaces and molecular adsorption on them. In particular, infrared-visible SFG as a surface vibrational spectroscopic technique has been employed to identify and monitor in-situ surface bonds and species on the diamond (111) surface. The CH stretch spectra allow us to investigate hydrogen adsorption, desorption, abstraction, and the nature of the hydrogen termination. The C(111) surface dosed with atomic hydrogen was found to be in a monohydride configuration with the hydrogen atoms situated at top-sites. The ratio of the abstraction rate to the adsorption rate was appreciable during atomic hydrogen dosing. Kinetic parameters for thermal desorption of H on C(111) were determined showing a near first-order kinetics. For the fully H-terminated (111) surface, a large (110 cm{sup {minus}1}) anharmonicity and {approximately}19 psec lifetime were measured for the first-excited CH stretch mode. The bare reconstructed C(111)-(2 {times} l) surface showed the presence of CC stretch modes which were consistent with the Pandey {pi}-bonded chain structure. When exposed to the methyl radical, the SFG spectra of the C(111) surface showed features suggesting the presence of adsorbed methyl species. After heating to sufficiently high temperatures, they were converted into the monohydride species. Preliminary results on the hydrogen-terminated diamond (100) surface are also presented.

Chin, R.P.

1995-04-01T23:59:59.000Z

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.


381

Neutrino Spectroscopy with Atoms and Molecules  

E-Print Network (OSTI)

We give a comprehensive account of our proposed experimental method of using atoms or molecules in order to measure parameters of neutrinos still undetermined; the absolute mass scale, the mass hierarchy pattern (normal or inverted), the neutrino mass type (Majorana or Dirac), and the CP violating phases including Majorana phases. There are advantages of atomic targets, due to the closeness of available atomic energies to anticipated neutrino masses, over nuclear target experiments. Disadvantage of using atomic targets, the smallness of rates, is overcome by the macro-coherent amplification mechanism. The atomic or molecular process we use is a cooperative deexcitation of a collective body of atoms in a metastable level |e> emitting a neutrino pair and a photon; |e> -> |g> + gamma + nu_i nu_j where nu_i's are neutrino mass eigenstates. The macro-coherence is developed by trigger laser irradiation. We discuss aspects of the macro-coherence development by setting up the master equation for the target quantum state and propagating electric field. With a choice of heavy target atom or molecule such as Xe or I_2 that has a large M1 x E1 matrix element between |e> and |g>, we show that one can determine three neutrino masses along with the mass hierarchy pattern by measuring the photon spectral shape. If one uses a target of available energy of a fraction of 1 eV, Majorana CP phases may be determined. Our master equation, when applied to E1 x E1 transition such as pH_2 vibrational transition Xv=1 -> 0, can describe explosive PSR events in which most of the energy stored in |e> is released within a few nanoseconds. The present paper is intended to be self-contained explaining some details related theoretical works in the past, and further reports new simulations and our ongoing experimental efforts of the project to realize the neutrino mass spectroscopy using atoms/molecules.

Atsushi Fukumi; Susumu Kuma; Yuki Miyamoto; Kyo Nakajima; Itsuo Nakano; Hajime Nanjo; Chiaki Ohae; Noboru Sasao; Minoru Tanaka; Takashi Taniguchi; Satoshi Uetake; Tomonari Wakabayashi; Takuya Yamaguchi; Akihiro Yoshimi; Motohiko Yoshimura

2012-11-21T23:59:59.000Z

382

THE DEEP SWIRE FIELD. III. WIYN SPECTROSCOPY  

SciTech Connect

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

383

Fundamentals of Quantum Chemistry: Molecular Spectroscopy and Modern Electronic Structure Computations (Mueller, Michael R.)  

Science Journals Connector (OSTI)

Fundamentals of Quantum Chemistry: Molecular Spectroscopy and Modern Electronic Structure Computations (Mueller, Michael R.) ...

Robert G. Mortimer

2003-01-01T23:59:59.000Z

384

Study of asymmetries of Cd(Zn)Te devices investigated using photo-induced current transient spectroscopy, Rutherford backscattering, surface photo-voltage spectroscopy, and gamma ray spectroscopies  

SciTech Connect

Despite these recent advancements in preparing the surface of Cd(Zn)Te devices for detector applications, large asymmetries in the electronic properties of planar Cd(Zn)Te detectors are common. Furthermore, for the development of patterned electrode geometries, selection of each electrode surface is crucial for minimizing dark current in the device. This investigation presented here has been carried out with three objectives. Each objective is oriented towards establishing reliable methods for the selection of the anode and cathode surfaces independent of the crystallographic orientation. The objectives of this study are (i) investigate how the asymmetry in I-V characteristics of Cd(Zn)Te devices may be associated with the TeO2 interfacial layer using Rutherford backscattering to study the structure at the Au-Cd(Zn)Te interface, (ii) develop an understanding of how the concentration of the active traps in Cd(Zn)Te varies with the external bias, and (iii) propose non-destructive methods for selection of the anode and cathode which are independent of crystallographic orientation. The spectroscopic methods employed in this investigation include Rutherford backscattering spectroscopy, photo-induced current transient spectroscopy, and surface photo-voltage spectroscopy, as well as gamma ray spectroscopy to demonstrate the influence on detector properties.

Crocco, J.; Bensalah, H.; Zheng, Q.; Dieguez, E. [Crystal Growth Laboratory, Universidad Autonoma de Madrid, Madrid Spain (Spain); Corregidor, V.; Avles, E. [Instituto Tecnologico e Nuclear UFA, Sacavem (Portugal); Castaldini, A.; Fraboni, B.; Cavalcoli, D.; Cavallini, A. [PHoS Laboratory, Department of Physics, University of Bologna, Bologna (Italy); Vela, O. [Centro de Investigacion Energeticas Medioambientales y Tecnologicas (CIEMAT), Madrid (Spain)

2012-10-01T23:59:59.000Z

385

Double pulse laser induced breakdown spectroscopy; experimental study of  

NLE Websites -- All DOE Office Websites (Extended Search)

Double pulse laser induced breakdown spectroscopy; experimental study of Double pulse laser induced breakdown spectroscopy; experimental study of lead emission intensity dependence on the wavelengths and sample matrix Title Double pulse laser induced breakdown spectroscopy; experimental study of lead emission intensity dependence on the wavelengths and sample matrix Publication Type Journal Article Year of Publication 2009 Authors Piscitelli, Vincent, Mauro A. Martinez, Alberto J. Fernandez, Jhanis J. Gonzalez, Xianglei Mao, and Richard E. Russo Journal Spectrochimica Acta Part B Volume 64 Issue 2 Pagination 147-154 Date Published 02/2009 Keywords Double pulse LIBS, laser induced breakdown spectroscopy, lead Abstract Lead (Pb) emission intensity (atomic line 405.78 nm) dependence on the sample matrix (metal alloy) was studied by means of collinear double pulse (DP)-laser induced breakdown spectroscopy (LIBS). The measurement of the emission intensity produced by three different wavelength combinations (i.e. I:532 nm-II:1064 nm, I:532 nm-II:532 nm, and I:532 nm-II:355 nm) from three series of standard reference materials showed that the lead atomic line 405.78 nm emission intensity was dependent on the sample matrix for all the combination of wavelengths, however reduced dependency was found for the wavelength combination I:532 nm-II:355 nm.

386

Ultrafast laser induced breakdown spectroscopy of electrode/electrolyte  

NLE Websites -- All DOE Office Websites (Extended Search)

Ultrafast laser induced breakdown spectroscopy of electrode/electrolyte Ultrafast laser induced breakdown spectroscopy of electrode/electrolyte interfaces Title Ultrafast laser induced breakdown spectroscopy of electrode/electrolyte interfaces Publication Type Journal Article Year of Publication 2012 Authors Zormpa, Vasileia, Jaroslaw Syzdek, Xianglei Mao, Richard E. Russo, and Robert Kostecki Journal Applied Physics Letters Volume 100 Issue 23 Date Published 05-2012 ISSN 0003-6951 Keywords electrochemical electrodes, graphite, high-speed optical techniques, laser beam effects, organic compounds, pyrolysis, solid electrolytes Abstract Direct chemical analysis of electrode/electrolyte interfaces can provide critical information on surface phenomena that define and control the performance of Li-based battery systems. In this work, we introduce the use of ex situ femtosecond laser induced breakdown spectroscopy to probe compositional variations within the solid electrolyte interphase (SEI) layer. Nanometer-scale depth resolution was achieved for elemental and molecular depth profiling of SEI layers formed on highly oriented pyrolytic graphite electrodes in an organic carbonate-based electrolyte. This work demonstrates the unique ability of ultrafast laser spectroscopy as a highly versatile, light element-sensitive technique for direct chemical analysis of interfacial layers in electrochemical energy storage systems.

387

Ion dip spectroscopy of cold molecules and ions. Progress report  

SciTech Connect

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

388

Analysis Tools for Next-Generation Hadron Spectroscopy Experiments  

E-Print Network (OSTI)

The series of workshops on New Partial-Wave Analysis Tools for Next-Generation Hadron Spectroscopy Experiments was initiated with the ATHOS 2012 meeting, which took place in Camogli, Italy, June 20-22, 2012. It was followed by ATHOS 2013 in Kloster Seeon near Munich, Germany, May 21-24, 2013. The third, ATHOS3, meeting is planned for April 13-17, 2015 at The George Washington University Virginia Science and Technology Campus, USA. The workshops focus on the development of amplitude analysis tools for meson and baryon spectroscopy, and complement other programs in hadron spectroscopy organized in the recent past including the INT-JLab Workshop on Hadron Spectroscopy in Seattle in 2009, the International Workshop on Amplitude Analysis in Hadron Spectroscopy at the ECT*-Trento in 2011, the School on Amplitude Analysis in Modern Physics in Bad Honnef in 2011, the Jefferson Lab Advanced Study Institute Summer School in 2012, and the School on Concepts of Modern Amplitude Analysis Techniques in Flecken-Zechlin near...

Battaglieri, M; Celentano, A; Chung, S -U; D'Angelo, A; De Vita, R; Döring, M; Dudek, J; Eidelman, S; Fegan, S; Ferretti, J; Fox, G; Galata, G; Garcia-Tecocoatzi, H; Glazier, D I; Grube, B; Hanhart, C; Hoferichter, M; Hughes, S M; Ireland, D G; Ketzer, B; Klein, F J; Kubis, B; Liu, B; Masjuan, P; Mathieu, V; McKinnon, B; Mitchell, R; Nerling, F; Paul, S; Pelaez, J R; Rademacker, J; Rizzo, A; Salgado, C; Santopinto, E; Sarantsev, A V; Sato, T; Schlüter, T; da Silva, M L L; Stankovic, I; Strakovsky, I; Szczepaniak, A; Vassallo, A; Walford, N K; Watts, D P; Zana, L

2014-01-01T23:59:59.000Z

389

INFRARED ABSORPTION SPECTROSCOPY AND CHEMICAL KINETICS OF FREE RADICALS  

NLE Websites -- All DOE Office Websites (Extended Search)

mNAL PERFORMANCE REPORT mNAL PERFORMANCE REPORT for INFRARED ABSORPTION SPECTROSCOPY AND CHEMICAL KINETICS OF FREE RADICALS DE-FG05-85ER13439 1-AUG-1985 to 31-JUL-1994 Robert F. Curl and Graham P. Glass Principal Investigators Introduction This research was directed at the detection, monitoring, and study (by infrared absorption spectroscopy) of the chemical kinetic behavior of small free radical species thought to be important intermediates in combustion. The work typically progressed from the detection and analysis of the infrared spectrum of combustion radical to the utilization of the infrared spectrum thus obtained in the investigation of chemical kinetics of the radical species. The methodology employed was infrared kinetic spectroscopy. In this technique the radical is produced by UV flash photolysis using an excimer laser and then

390

Optical and plasmonic spectroscopy with cantilever shaped materials  

NLE Websites -- All DOE Office Websites (Extended Search)

plasmonic spectroscopy with cantilever shaped materials plasmonic spectroscopy with cantilever shaped materials This article has been downloaded from IOPscience. Please scroll down to see the full text article. 2011 J. Phys. D: Appl. Phys. 44 445102 (http://iopscience.iop.org/0022-3727/44/44/445102) Download details: IP Address: 128.219.49.13 The article was downloaded on 28/12/2012 at 18:01 Please note that terms and conditions apply. View the table of contents for this issue, or go to the journal homepage for more Home Search Collections Journals About Contact us My IOPscience IOP PUBLISHING JOURNAL OF PHYSICS D: APPLIED PHYSICS J. Phys. D: Appl. Phys. 44 (2011) 445102 (9pp) doi:10.1088/0022-3727/44/44/445102 Optical and plasmonic spectroscopy with cantilever shaped materials L Tetard 1 , A Passian 1,2 , R H Farahi 1 , B H Davison 1 , A L Lereu 3 and T Thundat

391

Spectroscopy and reactions of vibrationally excited transient molecules  

SciTech Connect

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

392

2010 GRC VIBRATIONAL SPECTROSCOPY AUGUST 1 - AUGUST 6, 2010  

SciTech Connect

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

393

Single electron detection and spectroscopy via relativistic cyclotron radiation  

E-Print Network (OSTI)

It has been understood since 1897 that accelerating charges must emit electromagnetic radiation. Cyclotron radiation, the particular form of radiation emitted by an electron orbiting in a magnetic field, was first derived in 1904. Despite the simplicity of this concept, and the enormous utility of electron spectroscopy in nuclear and particle physics, single-electron cyclotron radiation has never been observed directly. Here we demonstrate single-electron detection in a novel radiofrequency spec- trometer. We observe the cyclotron radiation emitted by individual magnetically-trapped electrons that are produced with mildly-relativistic energies by a gaseous radioactive source. The relativistic shift in the cyclotron frequency permits a precise electron energy measurement. Precise beta elec- tron spectroscopy from gaseous radiation sources is a key technique in modern efforts to measure the neutrino mass via the tritium decay endpoint, and this work demonstrates a fundamentally new approach to precision beta spectroscopy for future neutrino mass experiments.

D. M. Asner; R. F. Bradley; L. de Viveiros; P. J. Doe; J. L. Fernandes; M. Fertl; E. C. Finn; J. A. Formaggio; D. Furse; A. M. Jones; J. N. Kofron; B. H. LaRoque; M. Leber; E. L. McBride; M. L. Miller; P. Mohanmurthy; B. Monreal; N. S. Oblath; R. G. H. Robertson; L. J Rosenberg; G. Rybka; D. Rysewyk; M. G. Sternberg; J. R. Tedeschi; T. Thummler; B. A. VanDevender; N. L. Woods

2014-08-22T23:59:59.000Z

394

Photon Sciences | Beamlines | SRX: Submicron Resolution X-ray Spectroscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

SRX: Submicron Resolution X-ray Spectroscopy SRX: Submicron Resolution X-ray Spectroscopy Poster | Fact Sheet | Preliminary Design Report Scientific Scope Scientific communities such as environmental sciences, life sciences, and material sciences have identified the need to develop analytical resources to advance the understanding of complex natural and engineered systems that are heterogeneous on the micron to nanometer scale. These needs for high intensity x-ray nanoprobes resulted in the commitment of the NSLS-II Project to build the Submicron Resolution X-ray (SRX) Spectroscopy beamline showing a unique combination of high spectral resolution over a very broad energy range and very high beam intensity in a sub-micrometer spot. NSLS-II will provide one of the best sources in the world for such an instrument.

395

2-2 Environmental Spectroscopy & Biogeochemistry Facility  

NLE Websites -- All DOE Office Websites (Extended Search)

ES&B Overview ES&B Overview Environmental Spectroscopy & Biogeochemistry Facility The Environmental Spectroscopy & Biogeochemistry (ES&B) Facility focuses on environ- mental molecular science and application of the fundamental concepts of physical chemistry to the study of chemical reactions in heterogeneous natural materials, with an emphasis on soil and subsurface systems. The ES&B Facility staff, along with other Pacific Northwest National Laboratory (PNNL) staff, form a multidisciplinary organization with expertise in chemistry, mineral physics, geochemistry, soil chemistry, microbiology, hydrology, and environmental engineering. Capabilities are available for materials characterization, aqueous-phase and solid-phase speciation and reaction/kinetic measurements, analytical environmental chemistry, molecular

396

Core-level spectroscopy of thin oxides and oxynitrides  

SciTech Connect

Several spectroscopic methods are discussed that use core levels, such as photoelectron spectroscopy and absorption spectroscopy with photoelectron or fluorescence detection. Measurements are presented on the desorption of a chemical oxide and the growth of oxynitrides with N{sub 2}0 on Si(100). The stoichiometry is found to change strongly with thickness, from a nitrogen-terminated Si surface to a nearly-pure oxide in the outer region of 40--60 {Angstrom} films. Using a third generation synchrotron beam line a sensitivity of better than a tenth of a monolayer is achieved by a simple photocurrent measurement.

Himpsel, F.J.; Akatsu, H. [International Business Machines Corp., Yorktown Heights, NY (United States). Thomas J. Watson Research Center; Carlisle, J.A. [Lawrence Livermore National Lab., CA (United States)] [and others

1994-07-19T23:59:59.000Z

397

Infrared absorption spectroscopy and chemical kinetics of free radicals  

SciTech Connect

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

398

Multiplexed absorption tomography with calibration-free wavelength modulation spectroscopy  

SciTech Connect

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

399

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

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

400

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

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.


401

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

402

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.

403

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

404

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

405

Volcano remote sensing with ground-based spectroscopy  

Science Journals Connector (OSTI)

...background. At Popocatepetl volcano, Mexico, they observed a steady increase in SiF4...measurements of volcanic gas compositions by solar FTIR spectroscopy. Nature, 396, 567-570...eruption plume at Popocatepetl volcano, Mexico. Nature, 396, 563-567. doi:10...

2005-01-01T23:59:59.000Z

406

Single atom identification by energy dispersive x-ray spectroscopy  

SciTech Connect

Using aberration-corrected scanning transmission electron microscope and energy dispersive x-ray spectroscopy, single, isolated impurity atoms of silicon and platinum in monolayer and multilayer graphene are identified. Simultaneously acquired electron energy loss spectra confirm the elemental identification. Contamination difficulties are overcome by employing near-UHV sample conditions. Signal intensities agree within a factor of two with standardless estimates.

Lovejoy, T. C.; Dellby, N.; Krivanek, O. L. [Nion, 1102 8th St., Kirkland, Washington 98033 (United States); Ramasse, Q. M. [SuperSTEM Laboratory, STFC Daresbury, Keckwick Lane, Daresbury WA4 4AD (United Kingdom); Falke, M.; Kaeppel, A.; Terborg, R. [Bruker Nano GmbH, Schwarzschildstr. 12, 12489 Berlin (Germany); Zan, R. [School of Physics and Astronomy, University of Manchester, Manchester M13 9PL (United Kingdom)

2012-04-09T23:59:59.000Z

407

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

408

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

409

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

410

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

411

Photoelectron spectroscopy of phosphorus hydride anions Kent M. Ervina  

E-Print Network (OSTI)

is a highly toxic gas that requires special handling procedures. The PH3 lec- ture bottle, regulator, and gas, University of Colorado and National Institute of Standards and Technology, and Department of Chemistry February 2005; published online 13 May 2005 Negative-ion photoelectron spectroscopy is applied to the PH

Lineberger, W. Carl

412

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

413

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

414

Shell-isolated nanoparticle-enhanced Raman spectroscopy  

E-Print Network (OSTI)

LETTERS Shell-isolated nanoparticle-enhanced Raman spectroscopy Jian Feng Li1 , Yi Fan Huang1 or in the form of nanoparticles, are required to realise a substantial SERS effect, and this has severely limited, we report an approach, which we name shell-isolated nanoparticle-enhanced Raman spectro- scopy

La Rosa, Andres H.

415

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

416

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

417

Laser photothermal spectroscopy of light-induced absorption  

SciTech Connect

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

418

Doppler optical mixing spectroscopy in multiparticle scattering fluids  

SciTech Connect

We discuss the basic scheme of laser Doppler optical mixing spectroscopy for the analysis of media with multiparticle scattering. It is shown that the Rayleigh scheme, in contrast to the heterodyne and differential schemes, is insensitive to the effects of multiparticle scattering. (laser applications and other aspects of quantum electronics)

Dubnishchev, Yu N [S S Kutateladze Institute of Thermophysics, Siberian Branch, Russian Academy of Sciences, Novosibirsk (Russian Federation)

2011-03-31T23:59:59.000Z

419

Single-Molecule Spectroscopy DOI: 10.1002/anie.201105388  

E-Print Network (OSTI)

Single-Molecule Spectroscopy DOI: 10.1002/anie.201105388 Single-Particle and Ensemble Diffusivities different approaches. The data obtained through the direct observation of dye molecule diffusion by single) with single-molecule sensitivity has recently provided us with a totally new view of diffusion

Ulm, Universität

420

Single Molecule Tip Enhanced Raman Spectroscopy NSF Grant # 1121262  

E-Print Network (OSTI)

MRSEC Single Molecule Tip Enhanced Raman Spectroscopy NSF Grant # 1121262 Matthew D. Sonntag1, it can "see" one single molecule at a time, this was carried out by studying the vibrational signature fingerprint that allows molecule identification. J. Phys. Chem. C, 2012, 116 (1), pp 478­483 · R6G-d4 · R6G-d0

Shahriar, Selim

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

Single-Molecule Spectroscopy DOI: 10.1002/ange.201105388  

E-Print Network (OSTI)

Single-Molecule Spectroscopy DOI: 10.1002/ange.201105388 Single-Particle and Ensemble Diffusivities different approaches. The data obtained through the direct observation of dye molecule diffusion by single) with single-molecule sensitivity has recently provided us with a totally new view of diffusion

Ulm, Universität

422

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

423

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

424

Structure and Reactivity of Semiconducting Mineral Surfaces: Convergence of Molecular Modeling and Experiment  

Science Journals Connector (OSTI)

...higher energy plane waves are important to describe the rapid oscillation of states in the vicinity of the core but, as will be discussed...Strongin DR, Schoonen MAA (1998) Photoemission of adsorbed xenon, x-ray photoemission spectroscopy, and temperature-programmed...

Kevin M. Rosso

425

Geophysical applications of nuclear resonant spectroscopy Wolfgang Sturhahn and Jennifer M. Jackson*  

E-Print Network (OSTI)

Geophysical applications of nuclear resonant spectroscopy Wolfgang Sturhahn and Jennifer M. Jackson* 17th August 2007 Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Ave, Argonne summarize recent developments of nuclear resonant spectroscopy methods like nuclear resonant inelastic x

Jackson, Jennifer M.

426

E-Print Network 3.0 - absorption spectroscopy Sample Search Results  

NLE Websites -- All DOE Office Websites (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...

427

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

NLE Websites -- All DOE Office Websites (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...

428

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

NLE Websites -- All DOE Office Websites (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...

429

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

430

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.

431

From electron energy-loss spectroscopy to multi-dimensional and multi-signal electron microscopy  

Science Journals Connector (OSTI)

......4 Colliex C . Electron Energy Loss Spectroscopy in the...eds. (1984) Vol. 9. New York: Academic Press. 65-177. 5 Egerton R . Electron Energy Loss Spectroscopy in the Electron Microscope (1986) New York: Plenum Press. 6 Isaacson......

Christian Colliex

2011-08-01T23:59:59.000Z

432

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

433

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

434

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

435

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.

436

Protein Characterisation by Synchrotron Radiation Circular Dichroism (SRCD) Spectroscopy  

SciTech Connect

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

437

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

NLE Websites -- All DOE Office Websites (Extended Search)

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

438

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

NLE Websites -- All DOE Office Websites (Extended Search)

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

439

Chapter 14 Treatise on Geochemistry Raman and Nuclear Resonant Spectroscopy in Geosciences  

E-Print Network (OSTI)

Chapter 14 Treatise on Geochemistry 1 Raman and Nuclear Resonant Spectroscopy in Geosciences Jung Advanced Photon Source, Argonne National Laboratory, Argonne, IL, USA Alexander F. Goncharov Geophysical technical advances in Raman and nuclear resonance spectroscopy (both Mössbauer spectroscopy and nuclear

Lin, Jung-Fu "Afu"

440

Self-normalizing phase measurement in multimode terahertz spectroscopy based on photomixing of three lasers  

E-Print Network (OSTI)

Photomixing of two near-infrared lasers is well established for continuous-wave terahertz spectroscopy. Photomixing of three lasers allows us to measure at three terahertz frequencies simultaneously. Similar to Fourier spectroscopy, the spectral information is contained in an nterferogram, which is equivalent to the waveform in time-domain spectroscopy. We use one fixed terahertz frequency \

Thirunavukkuarasu, K; Roggenbuck, A; Vidal, E; Schmitz, H; Hemberger, J; Grüninger, M

2014-01-01T23:59:59.000Z

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.


441

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

442

FRONTIER, MAGNETIC, ELLIPSOMETRIC AND TIME-RESOLVED INFRARED SPECTROSCOPY (FIS + MET)  

E-Print Network (OSTI)

FRONTIER, MAGNETIC, ELLIPSOMETRIC AND TIME-RESOLVED INFRARED SPECTROSCOPY (FIS + MET) SCIENTIFIC-resolved Frontier Infrared Spectroscopy (FIS) and Magnetic, Ellipsometric and Time-Resolved Infrared Spectroscopy Beamline Team STAFF Larry Carr: MET lead beamline scientist Zhenxian Liu (CIW): FIS lead beamline scientist

Ohta, Shigemi

443

Photon Statistics for Single-Molecule Nonlinear Spectroscopy F. Shikerman and E. Barkai  

E-Print Network (OSTI)

Photon Statistics for Single-Molecule Nonlinear Spectroscopy F. Shikerman and E. Barkai Department develop the theory of nonlinear spectroscopy for a single molecule undergoing stochastic dynamics-probe single-molecule system. Unlike the previous approaches to nonlinear spectroscopy where only the ensemble

Barkai, Eli

444

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.

445

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

446

Spin-Polarized Tunneling Spectroscopy in Tunnel Junctions with Half-Metallic Electrodes  

Science Journals Connector (OSTI)

We have studied the magnetoresistance (TMR) of tunnel junctions with electrodes of La2/3Sr1/3MnO3 and we show how the variation of the conductance and TMR with the bias voltage can be exploited to obtain precise information on the spin and energy dependence of the density of states. Our analysis leads to a quantitative description of the band structure of La2/3Sr1/3MnO3 including the energy gap ? between the Fermi level and the bottom of the t2g minority-spin band, in good agreement with data from spin-polarized inverse photoemission experiments. This shows the potential of magnetic tunnel junctions with half-metallic electrodes for spin-resolved spectroscopic studies.

M. Bowen, A. Barthélémy, M. Bibes, E. Jacquet, J.-P. Contour, A. Fert, F. Ciccacci, L. Duò, and R. Bertacco

2005-09-21T23:59:59.000Z

447

Dirac Charge Dynamcs in Graphene by Infrared Spectroscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Dirac Charge Dynamcs in Graphene by Infrared Spectroscopy Print 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 by applying a gate voltage. The charge carriers in graphene can travel ballistically over great distances (~1 micron) without scattering. These unusual electronic properties make graphene a promising candidate for future nanoelectronics. Using infrared spectromicroscopy at ALS Beamline 1.4, a group of researchers from the University of California at San Diego, Columbia University, and the ALS has succeeded in probing the dynamical properties of the charge carriers in graphene with an accuracy never before achieved. Their results have uncovered signatures of many-body interactions in graphene and have demonstrated the potential of graphene for novel applications in optoelectronics.

448

Microsoft PowerPoint - SpectroscopyTechniques_EXAFS  

NLE Websites -- All DOE Office Websites (Extended Search)

X-ray Absorption Fine Structure Spectroscopy (EXAFS) X-ray Absorption Fine Structure Spectroscopy (EXAFS) * Provides details on how x rays are absorbed by an atom at energies near X18A,B,X19A * Provides details on how x-rays are absorbed by an atom at energies near and above the core-level binding energies of that atom * Gives the modulation of an atom's x-ray absorption probability due to the chemical and physical state of the atom * Especially sensitive to the formal oxidation state, coordination chemistry, and the distances, coordination numbers, and species of the atoms immediately surrounding the selected element * Provides a practical, and relatively simple, way to determine the chemical state and local atomic structure for a selected atomic species

449

Dirac Charge Dynamcs in Graphene by Infrared Spectroscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Dirac Charge Dynamcs in Graphene by Infrared Spectroscopy Print 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 by applying a gate voltage. The charge carriers in graphene can travel ballistically over great distances (~1 micron) without scattering. These unusual electronic properties make graphene a promising candidate for future nanoelectronics. Using infrared spectromicroscopy at ALS Beamline 1.4, a group of researchers from the University of California at San Diego, Columbia University, and the ALS has succeeded in probing the dynamical properties of the charge carriers in graphene with an accuracy never before achieved. Their results have uncovered signatures of many-body interactions in graphene and have demonstrated the potential of graphene for novel applications in optoelectronics.

450

Applications of laser-induced gratings to spectroscopy and dynamics  

SciTech Connect

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

451

Theoretical description of spin-resolved appearance potential spectroscopy  

Science Journals Connector (OSTI)

A theoretical description of spin-resolved appearance potential spectroscopy is presented on the basis of a single-particle description of the underlying electronic structure. The final expression for the signal intensity turns out to be essentially a cross-section-weighted self-convolution of the density of states above the Fermi energy, in close analogy to the result for core-valence-valence Auger electron spectroscopy. Application of the formalism presented to bcc Fe and fcc Ni leads to results in very satisfying agreement with corresponding experimental data. Because this is achieved only by treating the involved transition matrix elements in a proper way, their properties are discussed in some detail.

H. Ebert and V. Popescu

1997-11-15T23:59:59.000Z

452

Single electron detection and spectroscopy via relativistic cyclotron radiation  

E-Print Network (OSTI)

It has been understood since 1897 that accelerating charges must emit electromagnetic radiation. Cyclotron radiation, the particular form of radiation emitted by an electron orbiting in a magnetic field, was first derived in 1904. Despite the simplicity of this concept, and the enormous utility of electron spectroscopy in nuclear and particle physics, single-electron cyclotron radiation has never been observed directly. Here we demonstrate single-electron detection in a novel radiofrequency spec- trometer. We observe the cyclotron radiation emitted by individual magnetically-trapped electrons that are produced with mildly-relativistic energies by a gaseous radioactive source. The relativistic shift in the cyclotron frequency permits a precise electron energy measurement. Precise beta elec- tron spectroscopy from gaseous radiation sources is a key technique in modern efforts to measure the neutrino mass via the tritium decay endpoint, and this work demonstrates a fundamentally new approach to precision beta sp...

Asner, D M; de Viveiros, L; Doe, P J; Fernandes, J L; Fertl, M; Finn, E C; Formaggio, J A; Furse, D; Jones, A M; Kofron, J N; LaRoque, B H; Leber, M; McBride, E L; Miller, M L; Mohanmurthy, P; Monreal, B; Oblath, N S; Robertson, R G H; Rosenberg, L J; Rybka, G; Rysewyk, D; Sternberg, M G; Tedeschi, J R; Thummler, T; VanDevender, B A; Woods, N L

2014-01-01T23:59:59.000Z

453

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

454

Chemometrics applied to vibrational spectroscopy: overview, challenges and pitfalls  

SciTech Connect

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

455

Dirac Charge Dynamcs in Graphene by Infrared Spectroscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Dirac Charge Dynamcs in Graphene 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 of carbon atoms arranged in a honeycomb lattice-has very high conductivity that can be tuned by applying a gate voltage. The charge carriers in graphene can travel ballistically over great distances (~1 micron) without scattering. These unusual electronic properties make graphene a promising candidate for future nanoelectronics. Using infrared spectromicroscopy at ALS Beamline 1.4, a group of researchers from the University of California at San Diego, Columbia University, and the ALS has succeeded in probing the dynamical properties of the charge carriers in graphene with an accuracy never before achieved. Their results have uncovered signatures of many-body interactions in graphene and have demonstrated the potential of graphene for novel applications in optoelectronics.

456

Raman/FTIR spectroscopy of oil shale retort gases  

SciTech Connect

A Raman facility was assembled in order to aid in the evaluation of the feasibility of using Raman or FTIR spectroscopy for analyzing gas mixtures of interest in oil shale. Applications considered in oil shale research included both retort monitoring and laboratory kinetic studies. Both techniques gave limits of detection between 10 and 1000 ppM for ten representative pertinent gases. Both techniques are inferior as a general analytical technique for oil shale gas analysis in comparison with mass spectroscopy, which had detection limits between 1 and 50 ppM for the same gases. The conclusion of the feasibility study was to recommend that mass spectroscopic techniques be used for analyzing gases of interest to oil shale.

Richardson, J H; Monaco, S B; Sanborn, R H; Hirschfeld, T B; Taylor, J R

1982-08-01T23:59:59.000Z

457

Integral Field Spectroscopy with the Gemini 8-m Telescopes  

E-Print Network (OSTI)

We give an overview of the current and future IFU capabilities on the Gemini 8-m telescopes. The telescopes are well-suited to integral field spectroscopy and both telescopes will have optical and near-infrared IFUs within the next few years. Commissioning for the GMOS IFU on Gemini North has begun recently and it is now available to the community. Future integral field instruments will take advantage of wide-field adaptive optics systems.

B. W. Miller; J. Turner; M. Takamiya; D. Simons; I. Hook

2002-03-20T23:59:59.000Z

458

Laser produced plasma diagnostics by cavity ringdown spectroscopy and applications  

SciTech Connect

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

459

Pressure dependent diffraction and spectroscopy of a dimerized antiferromagnet  

SciTech Connect

We present pressure dependent neutron diffraction and inelastic neutron scattering measurements of the dimerized antiferromagnet Ba$_3$Mn$_2$O$_8$. The room temperature diffraction measurements reveal a linear decrease in lattice constant as a function of applied pressure. No structural transitions are observed. The low-temperature neutron spectroscopy measurements indicate a small change in magnetic scattering intensity in the vicinity of the spin gap for pressures up to $P=0.6$~kbar.

Stone, Matthew B [ORNL; Tulk, Christopher A [ORNL; dos Santos, Antonio M. [Oak Ridge National Laboratory (ORNL); Molaison, Jamie J [ORNL; Chang, S. [Ames Laboratory; Leo, J B [National Institute of Standards and Technology (NIST), Gaithersburg, MD; Samulon, Eric C [Stanford University; Shapiro, Max C [Stanford University; Fisher, Ian R [Stanford University

2011-01-01T23:59:59.000Z

460

Sapphire analyzers for high-resolution x-ray spectroscopy.  

SciTech Connect

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

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

Determination of lead in gasoline by atomic absorption spectroscopy  

Science Journals Connector (OSTI)

A procedure has been developed for the direct determination of lead in gasoline by atomic absorption spectroscopy. This procedure is rapid, does not require expensive equipment, is remarkably free from interference by other trace elements present, and allows considerable variation in the sulfur and nitrogen content of the gasoline. It compares favorably with other existing procedures for this determination, such as X-ray fluorescence, wet chemical methods, and flame photometry.

J.W. Robinson

1961-01-01T23:59:59.000Z

462

Alternative Sample Preparation of Soils for Gamma Spectroscopy  

SciTech Connect

Standard laboratory procedures for preparation of soil samples for analysis by gamma spectroscopy typically utilize drying and grinding. Drying of soil samples can be accomplished using an oven for 8 to 16 hours or by air for several days or weeks. Dried samples are then sieved and / or ground to facilitate homogenization. The sample preparation process for soils adds significant time for analysis by gamma spectroscopy as the actual analysis is normally on the order of 1 hour or less. An alternative approach has been developed that significantly reduces sample preparation time for soil samples and that provides comparable results to those obtained by the standard method. The alternative approach utilizes a moisture analyzer to determine the percent moisture in each individual sample, which takes 15 to 45 minutes for each sample. The actual weight of the sample is then corrected by the percent moisture in order to report the results on the equivalent dry weight. This is especially important for samples that are for decision making associated with field activities where time is of the essence. This alternative sample preparation approach provides fast and efficient sample preparation of soils for gamma spectroscopy without reducing data quality or imparting bias. (authors)

Downey, H.T. [MACTEC, Portland, ME (United States); Jung, P.; Scarborough, R. [Sevenson Environmental Services, Niagara Falls, NY (United States)

2008-07-01T23:59:59.000Z

463

Raman spectroscopy on simple molecular systems at very high density  

SciTech Connect

We present an overview of how Raman spectroscopy is done on simple molecular substances at high pressures. Raman spectroscopy is one of the most powerful tools for studying these substances. It is often the quickest means to explore changes in crystal and molecular structures, changes in bond strength, and the formation of new chemical species. Raman measurements have been made at pressures up to 200 GPa (2 Mbar). Even more astonishing is the range of temperatures (4-5200/degree/K) achieved in various static and dynamic (shock-wave) pressure experiments. One point we particularly wish to emphasize is the need for a good theoretical understanding to properly interpret and use experimental results. This is particularly true at ultra-high pressures, where strong crystal field effects can be misinterpreted as incipient insulator-metal transitions. We have tried to point out apparatus, techniques, and results that we feel are particularly noteworthy. We have also included some of the /open quotes/oral tradition/close quotes/ of high pressure Raman spectroscopy -- useful little things that rarely or never appear in print. Because this field is rapidly expanding, we discuss a number of exciting new techniques that have been informally communicated to us, especially those that seem to open new possibilities. 58 refs., 18 figs.

Schiferl, D.; LeSar, R.S.; Moore, D.S.

1988-01-01T23:59:59.000Z

464

Satellites in x-ray photoelectron spectroscopy of insulators. II. Multielectron excitations in LiF, NaF, and KF  

Science Journals Connector (OSTI)

The satellites appearing in the core regions of the x-ray photoelectron spectra of alkali fluorides have been investigated in order to obtain information about the distribution of interband transitions. The photoemission results are compared with some recent theoretical band-structure calculations. The differences in the relative intensities observed in the different core regions are ascribed to the presence of excitons in the spectra.

Marisa Scrocco

1985-07-15T23:59:59.000Z

465

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

SciTech Connect

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

466

Untitled Document  

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to the related x-ray photoemission spectroscopy (XPS or ESCA) technique, where the photon energy is fixed and the electron intensity is measured as a function of electron kinetic...

467

BulletinVol. 65 -No. 2 January 14, 2011 Whaddya know? It was one  

E-Print Network (OSTI)

through it with very little, if any, resistance. Fast forward one hundred years: now we are looking, Neville Smith. In photoemission spectroscopy, physicists shoot a photon, the elementary particle of light

468

Results from Point Contact Tunnelling Spectroscopy and Atomic Layer Deposition  

SciTech Connect

We have shown previously that magnetic niobium oxides can influence the superconducting density of states at the surface of cavity-grade niobium coupons. We will present recent results obtained by Point Contact Tunneling spectroscopy (PCT) on coupons removed from hot and cold spots in a niobium cavity, as well as a comparative study of magnetic oxides on mild baked/unbaked electropolished coupons. We will also describe recent results obtained from coated cavities, ALD films properties and new materials using Atomic Layer Deposition (ALD).

Proslier, Th. [Illinois Institute of Technology; Zasadzinski, J. [Illinois Institute of Technology; Ciovati, Gianluigi [JLAB; Kneisel, Peter K. [JLAB; Elam, J. W. [ANL; Norem, J. [ANL; Pellin, M. J. [ANL

2009-11-01T23:59:59.000Z

469

Elastic properties of gamma-Pu by resonant ultrasound spectroscopy  

SciTech Connect

Despite intense experimental and theoretical work on Pu, there is still little understanding of the strange properties of this metal. We used resonant ultrasound spectroscopy method to investigate the elastic properties of pure polycrystalline Pu at high temperatures. Shear and longitudinal elastic moduli of the {gamma}-phase of Pu were determined simultaneously and the bulk modulus was computed from them. A smooth linear and large decrease of all elastic moduli with increasing temperature was observed. We calculated the Poisson ratio and found that it increases from 0.242 at 519K to 0.252 at 571K.

Migliori, Albert [Los Alamos National Laboratory; Betts, J [Los Alamos National Laboratory; Trugman, A [Los Alamos National Laboratory; Mielke, C H [Los Alamos National Laboratory; Mitchell, J N [Los Alamos National Laboratory; Ramos, M [Los Alamos National Laboratory; Stroe, I [WORXESTER, MA

2009-01-01T23:59:59.000Z

470

Molecular shock response of explosives: electronic absorption spectroscopy  

SciTech Connect

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

471

PHOTOMETRICALLY TRIGGERED KECK SPECTROSCOPY OF FERMI BL LACERTAE OBJECTS  

SciTech Connect

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

472

High performance computing activities in hadron spectroscopy at BESIII  

Science Journals Connector (OSTI)

BESIII experiment is operated in the ?-charm threshold energy region. It has collected the world's largest data samples of J/?, ?(3686), ?(3770) and ?(4040) decays. These data are being used to make a variety of interesting and unique studies of light hadron spectroscopy, precision charmonium physics and high-statistics measurements of D meson decays. As one of the experiments at the high luminosity frontier, data processing at BESIII is computationally very expensive for large data sets. In this presentation, we report two recent progresses in using high performance computing: a Tag-based preselection for data reduction and GPUPWA, a PWA framework harnessing the GPU parallel computing.

Beijiang Liu; Besiii collaboration

2014-01-01T23:59:59.000Z

473

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

474

Resolving The ISM Surrounding GRBs with Afterglow Spectroscopy  

SciTech Connect

We review current research related to spectroscopy of gamma-ray burst (GRB) after-glows with particular emphasis on the interstellar medium (ISM) of the galaxies hosting these high redshift events. These studies reveal the physical conditions of star-forming galaxies and yield clues to the nature of the GRB progenitor. We offer a pedagogical review of the experimental design and review current results. The majority of sightlines are characterized by large HI column densities, negligible molecular fraction, the ubiquitous detection of UV pumped fine-structure transitions, and metallicities ranging from 1/100 to nearly solar abundance.

Prochaska, J. X. [Lick Observatory, University of California, Santa Cruz (United States); Chen, H.-W. [Dept. of Astronomy and Astrophysics and Kavli Institute for Cosmological Physics, University of Chicago (United States); Dessauges-Zavadsky, M. [Observatoire de Geneve, Sauverny Switzerland (Switzerland); Bloom, J. S. [Department of Astronomy, University of California, Berkeley (United States)

2008-05-22T23:59:59.000Z

475

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.

Leach, K G; Grossheim, A; Andreoiu, C; Dilling, J; Frekers, D; Good, M; Seeraji, S

2014-01-01T23:59:59.000Z

476

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

477

Photoelectron spectroscopy of boron aluminum hydride cluster anions  

SciTech Connect

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

478

Raman spectroscopy of selected arsenates—implications for soil remediation  

Science Journals Connector (OSTI)

The contamination of soils with heavy metals such as As, Cr and Cu is of great importance; the remediation of such soils even more so. Arsenic compounds are prevalent in soils either through leaching of mine tailings, the use of Cu/Cr/As as a wood preservative or through the use of arsenic in cattle dips. The arsenic compounds in soils and leachates can be highly reactive and mobile, resulting in the formation of metal arsenate compounds. Of these compounds, one such set of minerals that can be formed is the vivianite arsenate minerals. Raman spectroscopy has been used to characterise the vivianite arsenates and to identify arsenic contaminants in a soil.

Ray L. Frost; Theo Kloprogge; Matthew L. Weier; Wayde N. Martens; Z. Ding; Howell G.H. Edwards

2003-01-01T23:59:59.000Z

479

10 Questions for a Spectroscopy Expert: Nancy Hess | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Spectroscopy Expert: Nancy Hess Spectroscopy Expert: Nancy Hess 10 Questions for a Spectroscopy Expert: Nancy Hess April 14, 2011 - 4:34pm Addthis Nancy Hess | Photo Courtesy of Pacific Northwest National Lab (PNNL) Nancy Hess | Photo Courtesy of Pacific Northwest National Lab (PNNL) Niketa Kumar Niketa Kumar Public Affairs Specialist, Office of Public Affairs "I have always enjoyed the beauty and the complexity of processes in the natural world -- Spectroscopy gives you that insight." Nancy Hess, Spectroscopy Expert Meet Nancy Hess -- an expert in spectroscopy (i.e. the change in light intensity and/or frequency resulting from its interaction with matter that gives information about electronic structure, geometry and chemical bonds). At Pacific Northwest National Lab (PNNL), she leads the

480

A spectrally programmable light engine for in vitro or in vivo molecular imaging and spectroscopy  

Science Journals Connector (OSTI)

Spectrally and temporally programmable light source can be used in a wide range of medical photonics instruments in spectroscopy, microscopy and endoscopy and can create any desired...

MacKinnon, Nicholas B; Quatrevalet, Matthieu; Lane, Pierre; Stange, Ulrich; MacAulay, Calum

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.


481

E-Print Network 3.0 - absorption gamma-ray spectroscopy Sample...  

NLE Websites -- All DOE Office Websites (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,...

482

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

483

Laser Induced Breakdown Spectroscopy to Detect Copper Contamination in Transformer Insulation  

Science Journals Connector (OSTI)

Laser Induced Breakdown Spectroscopy combined with a laser-ablation based depth profiling technique is demonstrated for the detection of copper contamination in transformer insulation....

Aparna, N; Wazeem, M A; Vasa, Nilesh J; Sarathi, R; Sundara Rajan, J

484

E-Print Network 3.0 - atr-ftir spectroscopy study Sample Search...  

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Technologies and Information Sciences 2 Using Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy to Investigate the Surface Chemistry of a Drying Summary:...

485

E-Print Network 3.0 - atr ftir spectroscopy Sample Search Results  

NLE Websites -- All DOE Office Websites (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:...

486

E-Print Network 3.0 - atr-ftir spectroscopy detects Sample Search...  

NLE Websites -- All DOE Office Websites (Extended Search)

microscopy and lateral... by polarized attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. The bilayers... and lipid- protein interactions in...

487

Calibration-free wavelength modulation spectroscopy applications from combustion to medical science  

Science Journals Connector (OSTI)

Calibration-free wavelength modulation spectroscopy was employed for measuring temperature and H2O concentration in combustion environments with a near-infrared DFB-laser,...

Qu, Zhechao; Schmidt, Florian

488

Characterization of Woody and Herbaceous Biomasses Lignin Composition with 1064 nm Dispersive Multichannel Raman Spectroscopy  

Science Journals Connector (OSTI)

Biomass representing different classes of bioenergy feedstocks, including woody and herbaceous species, was measured with 1064 nm Raman spectroscopy. Pine, oak, poplar, kenaf,...

Lupoi, Jason S; Smith, Emily A

2012-01-01T23:59:59.000Z

489

Looking Inside Catalyst Extrudates with Time-Resolved Surface-Enhanced Raman Spectroscopy (TR-SERS)  

Science Journals Connector (OSTI)

Raman spectroscopy is one of the major characterization methods employed over the last few decades as a nondestructive technique for the study of heterogeneous catalysts and related...

Harvey, Clare E; Petterson, Ingeborg E Iping; Weckhuysen, Bert M; Gooijer, Cees; Ariese, Freek; Mank, Arjan J G

2012-01-01T23:59:59.000Z

490

Investigation of the Role of Trap States in Solar Cell Reliability using Photothermal Deflection Spectroscopy.  

E-Print Network (OSTI)

??Stability and reliability of solar cells are crucial for utilizing them for solar energy technology. In this dissertation work photothermal deflection spectroscopy (PDS) technique was… (more)

Bezryadina, Anna Sergeyevna

2012-01-01T23:59:59.000Z

491

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

492

Spectroscopy, photo-physics, and time resolved exciton dynamics of GaSe quantum dots  

E-Print Network (OSTI)

MERCED Spectroscopy, Photo-physics, and Time Resolvedresolve this issue is to photo-select the heterostructuresof particles is first photo-selected by polarized excitation

Mirafzal, Hoda

2011-01-01T23:59:59.000Z

493

E-Print Network 3.0 - absorption spectroscopies progress Sample...  

NLE Websites -- All DOE Office Websites (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...

494

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

495

Testing and Evaluation Protocol for Spectroscopy-Based Portal Monitors Used for Homeland Security  

E-Print Network (OSTI)

Testing and Evaluation Protocol for Spectroscopy- Based Portal Monitors Used for Homeland Security................................................................................1 4. Test and evaluation steps .........................................................................................1 5. Recording test results

496

The Use of UV–Vis Absorption Spectroscopy for Studies of Natively Disordered Proteins  

Science Journals Connector (OSTI)

Absorption spectroscopy can be used to monitor structural changes upon transitions from ordered to disordered state in proteins. Changes in environment of tryptophan, tyrosine,...

Eugene A. Permyakov

2012-01-01T23:59:59.000Z

497

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

NLE Websites -- All DOE Office Websites (Extended Search)

gas analysis Alexander Fateev, Snnik Clausen Summary: applications and in particular in atomicmolecular absorption spectroscopy, the transition moment is replaced... +CO+CO2)....

498

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

NLE Websites -- All DOE Office Websites (Extended Search)

gas analysis Alexander Fateev, Snnik Clausen Summary: applications and in particular in atomicmolecular absorption spectroscopy, the transition moment is replaced... +CO+CO2)....

499

Probing Vibrational Energy Transfer in DNA Nucleobases with Mid-UV Four-Wave Mixing Spectroscopies  

Science Journals Connector (OSTI)

Heterodyne-detected four-wave mixing spectroscopies are used to investigate vibrational energy transfer in various DNA nucleobases. Unique insights into the solute-solvent couplings...

West, Brantley A; Womick, Jordan M; Moran, Andrew M

500

Solar Energy Conversion Processes in Nanostructured Materials Studied via Time-Resolved THz Spectroscopy  

Science Journals Connector (OSTI)

We discuss time-resolved THz spectroscopy measurements for three important solar energy conversion approaches; (1) electronically coupled semiconductor nanocrystals, (2) a bulk...

Beard, Matt; Blackburn, Jeffery; Heben, Michael; Ai, Xin; Rumbles, Garry; Ellingson, Randy J; Nozik, Arthur J