The first direct measurement of the fluorine-atom ground state fine structure transition, using diode laser absorption spectroscopy, is reported. The fine structure absorption line position (spin-orbit energy splitting), measured with high precision ...
National Technical Information Service (NTIS)
... Title : LASER-EXAFS: FAST EXTENDED X-RAY ABSORPTION FINE STRUCTURE SPECTROSCOPY WITH A SINGLE PULSE OF LASER ...
DTIC Science & Technology
near-edge x-ray absorption fine-structure (NEXAFS) spectroscopy, allows for quantitative determination of submicron polymer blend composition. At a lateral resolution of 50 nm,...
Science.gov Websites
... SPECTROSCOPY, SEMICONDUCTORS, PHOTONS, TELLURIUM ALLOYS, GERMANIUM ALLOYS, ANTIMONY ALLOYS, ELECTRONICS, X RAY ...
... The first result, direct detection of intrinsic static absorption fine structure on a ... the spectral density of absorbers which scale as the square root of the ...
... x-ray absorption fine structure (EXAFS), infra-red and Raman spectroscopy, low temperature specific heat, and electron spin resonance (ESR). ...
... Title : ON THE THEORY OF THE FINE STRUCTURE OF THE X RAY ABSORPTION SPECTRA OF IONS IN SOLUTIONS. ...
The oxygen binding site of hemocyanin has two copper atoms coordinated to the side chains from the polypeptide chain. Copper extended x-ray absorption fine structure (EXAFS) and absorption edges of the protein were studied. Comparison of EXAFS from three ...
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 mo...
The structures of initial and final products of bromoalkanes' photodisociation reaction in cyclohexane solution have been measured with a bond length accuracy of 0.02 ? by means of ultrafast time-resolved extended x-ray absorption fine structure spectroscopy. The photoredaction mechanism is also discussed.
PubMed Central
Near-Edge X-ray Absorption Fine Structure Spectroscopy of MDI and TDI Polyurethane Polymers Stephen) to differences in key chemical components of polyurethane polymers is presented. Carbon 1s NEXAFS spectra of polyurethane polymers made from 4,4-methylene di-p-phenylene isocyanate (MDI) and toluene diisocyanate ...
E-print Network
When two or more absorption edges in a material are sufficiently close in energy, Extended X-ray- Absorption Fine-Structure (EXAFS) spectroscopy is of limited utility as the usable data range above the lower energy edge is truncated by the higher energy e...
Near edge x-ray absorption fine structure (NEXAFS) and infrared reflection-absorption spectroscopy (IRRAS) have been used to study the orientational behavior of thin films of poly(3-methylthiophene) electrochemically polymerized on a platinum surface. Cle...
The experimental technics of Extended X-ray Absorption Fine Structure (EXAFS) is presented and several uses of it in atomic, molecular and bio physics are shown. The recent progresses of this technics, both theoretical and experimental, are discussed and ...
... X-ray absorption fine structure (XAFS) spectroscopy is an ... were examined initially by powder X-ray diffraction (XRD ... around the Ni K-edge (8333 eV ...
The main purpose of this Study Weekend was to review the contributions that the measurement and interpretation of X-ray absorption spectroscopy, particularly Extended X-ray Absorption Fine Structure (EXAPS), has made, and can make, to the improved underst...
X-ray absorption spectroscopy is now being applied to the study of a wide range of surface structures. The usefulness of surface EXAFS (SEXAFS) is illustrated by reviewing measurements on the oxidation of aluminum, the absorption of Te and I on silicon an...
Variable incidence angle X-ray absorption fine structure (VIAXAFS) spectroscopy offers a non-destructive ability to investigate film nano-structures. This technique was applied, spanning sample-beam angles from a grazing to normal incidence on a film obtained by zirconia sputtering on flat sample of stainless ...
PubMed
We study the temperature evolution of aluminum nanoparticles generated by femtosecond laser ablation with spatiotemporally resolved x-ray-absorption fine-structure spectroscopy. We successfully identify the nanoparticles based on the L-edge absorption fine structure of the ...
Energy Citations Database
... statistical fine structure (SFS) in the inhomogeneously broadened optical absorption of pentacene in ... size of the SFS varies as the square root of the ...
The research presented elucidates the oxidation chemistry occurring in hydrogen peroxide bleached kraft pulp fibers by employing carbon near edge x-ray ... ...
NBII National Biological Information Infrastructure
Diamondoids, hydrocarbon molecules with cubic-diamond-cage structures, have unique properties with potential value for nanotechnology. The availability and ability to selectively functionalize this special class of nanodiamond materials opens new possibil...
and poly(9,9'-dioctylfluorene-co-benzothiadiazole) (F8BT). STXM, in conjunction with the chemical sensitivity of near-edge x-ray absorption fine-structure (NEXAFS) spectroscopy,...
... Near edge X-ray absorption fine structure (NEXAFS) spectroscopy ... The X-ray beam was elliptically polarized ... which in- cludes the carbon K edge. ...
... analysis of the kX spectrum up to 800 eV above the K edge. ... We have applied extended x-ray absorption fine structure (EXAFS) spectroscopy [1] to ...
-hyper- accumulating plants. Keywords: X-ray absorption fine structure spectroscopy (XAFS), metal- hyperaccumulator metal accumulating plants (hyperaccumulators) proposed as an alternative remediation strategy for this site. �-XAFS AND �-SXRF ANALYSIS OF METALS IN HYPERACCUMULATOR PLANTS Alternative remediation
The following were studied: confinement of block copolymers, free surface confinement, effects of substrate interactions, random copolymers at homopolymer interfaces, phase separation in thin film polymer mixtures, buffing of polymer surfaces, and near edge x-ray absorption fine structure spectroscopy.
This report discusses work on the characterization by extended x-ray absorption fine structure spectroscopy, structures formed on the surface of partially dehydroxylated magnesium oxides by adsorption of (HRe(CO){sub 5}).
DOE Information Bridge
. Nucleic Acids Res. 23:3627�32 7. Peterlinz KA, Georgiadis RM, Herne TM, Tarlov MJ. 1997. J. Am. Chem. Soc
more competitive for widespread implementation was obtained using near-edge x-ray absorption fine structure (NEXAFS) spectroscopy performed at ALS Beamline 8.0.1. The relevant...
pp. 293-296. 293. Lunar and Planetary. Institute,. Houston,. 1992 .... absorption fine structure spectroscopy. (NEXAFS). In the targets exposed to vacuum ...
NASA Website
One of the long term research goals has been to attain a quantitative theory of deep core X-ray spectroscopies. These spectroscopies include X-ray absorption fine structure (XAFS), X-ray absorption near edge structure (XANES), X-ray magnetic circular dich...
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 ...
Ti K and Ti L{sub 2,3} x-ray absorption fine-structure near-edge spectra of SrTiO3 thin films grown coherently on Si(001) reveal the presence of a ferroelectric (FE) distortion at room temperature. This unique phase is a direct consequence of the compressive biaxial strain achieved by coherent epitaxial growth.
The local structure of monoclinic, monohydrate, hexagonal, and pyrochlore WO3 phases was investigated by the extended x-ray absorption fine structure spectroscopy as preliminary studies of model compounds of amorphous and thin film WO3 based electrochromic species. In the four cases, we found a large W-O ...
X-ray absorption spectroscopy was used to characterize the metal-support interface in catalysts consisting of very small Ir clusters of nearly uniform nuclearity on the surface of MgO powder. [Ir[sub 4](CO)[sub 12
of the DCM was calibrated relative hal-00261713,version1-8Mar2008 #12;15 to the Au K-edge of metallic gold-ray absorption near-edge spectroscopy) and EXAFS (extended x-ray absorption fine- structure) spectroscopy. Iterative transformation factor analysis of XANES and EXAFS ...
... Abstract : First application of extended x-ray absorption fine structure (EXAFS) technique to measurements of interatomic distance, local order, and ...
... of EXAFS (Extended xray absorption fine structure ... have recorded the extended x-ray-absorption fine structure ... above the carbon K edge for diamond ...
... Title : EXTENDED X-RAY ABSORPTION FINE STRUCTURE: A MODERN STRUCTURAL TOOL IN MATERIALS SCIENCE. Corporate Author : ...
The rates of fine structure relaxation in PbS, PbSe, and PbTe nanocrystals were measured on a femtosecond time scale as a function of temperature with no applied magnetic field by cross-polarized transient grating spectroscopy (CPTG) and circularly polarized pump-probe spectroscopy. The relaxation rates among ...
This investigation describes the formation of a metal nanorattle with a pure metal shell by varying experimental parameters. The galvanic replacement reaction between silver and chloroauric acid was adopted to prepare hollow metal nanoparticles. This approach is extended to produce nanorattles of Au cores and Au shells by starting with Au(core)Ag(shell) nanoparticles as templates. The effect of ...
Often, precision measurements from diverse fields can be used to learn new facts about the universe. The usual definition of "precision" is based on improvements over previous measurements. A review of the present state of knowledge regarding the possible time variation of the fine structure constant ? will be presented; "precise" data from natural ...
NASA Astrophysics Data System (ADS)
We demonstrate the feasibility of near edge x-ray absorption fine structure spectroscopy on solids by means of femtosecond soft x-ray pulses from a free-electron laser (FEL). Our experiments, carried out at the FEL at Hamburg used a special sample geometry, spectrographic energy dispersion, single shot ...
The technique of x-ray absorption spectroscopy using tuneable, very intense x-rays from a high energy electron storage ring has been applied to study of the estended x-ray absorption fine structure for Cu and Ni tetraphenylporphyrin and methemoglobin. Preliminary analysis shows that the spectra ...
A program to investigate the x-ray absorption behavior of materials subjected to high pressures has been continued. Of particular interest has been the EXAFS (extended x-ray absorption fine structure) and XANES (x-ray absorption near edge structure). Mate...
The techniques of extended x-ray absorption fine structure (EXAFS), and x-ray absorption edge spectroscopy (XAES) are used to obtain specific structural information about the manganese coordination environment in synthetic inorganic complexes, and in biol...
K-absorption edge of coordinated ions exhibits a fine structure (through the use of XANES, or x-ray absorption near edge structures) that reflects the electronic repartition and the chemical reactivity of these ions. Comparative analysis of iron K-absorption-edge shape for hemoglobin ...
The nature of the surface formed by a saturated layer ({Theta}(NO) = 1.0) of NO on a Mo(100) surface at 150 K has been determined by using both angle-resolved ultraviolet photoelectron spectroscopy and the angular variation of near-edge x-ray absorption fine structure (NEXAFS). Photoelectron ...
The spectroscopy of colloidal CdSe nanocrystals is investigated using two-dimensional photon echo (2DPE) spectroscopy with copolarized and cross-polarized pulse sequences. Clearly resolved excited state absorption features are observed to beat at the frequency of the longitudinal-optical phonon, and the phase of this beating is found ...
The L3 edge of bulk Au has been studied using x-ray-absorption spectroscopy in the temperature range 16-300 K. An effective Debye temperature of 165 K is derived from the thermal behavior of the extended x-ray absorption fine-structure Debye-Waller factors. Their behavior is also calculated for finite systems by ...
New concepts for time-resolved x-ray absorption spectroscopy using the quick-extended x-ray absorption fine structure (QEXAFS) method are presented. QEXAFS is a powerful tool to gain structural information about, e.g., fast chemical reactions or phase transitions on a subsecond scale. This can ...
The extended x-ray absorption fine structure (EXAFS) is the oscillation in the absorption coefficient extending a few hundred eVs on the high energy side of an x-ray absorption edge. This mode of spectroscopy has recently been realized to be a powerful tool in probing the ...
The sensitivity of x-ray absorption edge spectra and extended x-ray absorption fine structure (EXAFS) to the environment of metal atoms make x-ray absorption spectroscopy a useful probe of the environment of the molybdenum in nitrogenase. It is of particular interest to ...
We propose to develop a quantitative theory of x-ray spectroscopies in the near edge region, within about 100 eV of threshold. These spectroscopies include XAFS (X-ray absorption fine structure), photoelectron diffraction (PD), and diffraction anomalous fine ...
(p-phenylene terephthalamide) (Kevlar), poly(ethylene terephthalate), poly(p-phenylene-1,3,4-oxadiazole), and 2,5-di. Samples of poly(p-phenylene terephthalamide) (Kevlar), poly- (ethylene terephthalate) (PET), poly-ray absorption spectra of AF51, Kevlar, PET, and PPOD for fingerprinting. The interpretation of the spectral
The results of magnetic circular x-ray dichroism (MCXD) measurements and extended x-ray absorption fine structure measurements (EXAFS) of the Fe K-edges of textured Fe(110)/Pd(111) multilayers are reported. The EXAFS results indicates that the iron in the...
We study carrier dynamics in CdSe colloidal quantum dots (QDs) using femtosecond photoluminescence and transient absorption spectroscopies. We resolve hole relaxation between the high- and low-energy fine-structure states that are responsible for the band-edge absorption and emission, respectively. We derive a ...
The author has used the extended X-ray absorption fine structure (EXAFS) and ultra-low temperature X-ray magnetic circular dichroism (XMCD) to study the environments of the metal sites in metalloproteins. EXAFS has been used to study the Zn site in spinac...
Analysis of the extended x-ray absorption fine structure led to the proposal of a model for the binuclear type 3 copper site in which the Cu atoms are separated by 3.55 A. Results on oxyhemocyanins from two different species (Megathura crenulata and Helix pomatia) are compared. (DLC)
X-ray absorption fine structure (XAFS spectroscopy data were obtained from particulate samples produced by the combustion of residual fuel oil in a 732-kW fire-tube boiler at EPA's National Risk Management Research Laboratory in North Carolina. Residual oil flyash (ROFA) from fo...
EPA Science Inventory
X-ray absorption fine structure (XAFS) spectroscopy has been used to investigate the valence states and molecular structures of sulfur (S), chromium (Cr), arsenic (As), and zinc (Zn) in fine particulate matter (PM) separated from coal flyash produced in a realistic combustion sys...
This report describes a new method for determining all major forms of organic and inorganic sulfur found in coal, based on least-squared fitting of sulfur K-edge XANES spectra. It also fully examined three powerful analytic techniques: computer-controlled scanning electron microscopy (CCSEM), X-ray absorption fine structure (XAFS) ...
Extended x-ray absorption fine structure (EXAFS) spectroscopy has been used to determine the structural environment local to iron(HI) and zircorium(IV) cations in respectively, nanoscale iron oxyhydroxide and nanoscale zirconium oxide powders. The iron ox...
... i059-02 (1953) On the Theory of the Fine Structure the X-Ray Absorption Spectra of ions in Solutions E. Ye. Vainshtein ...
Arsenic is present in low concentrations in much of the Earth's crust and changes in its speciation are vital to understanding its transport and toxicity in the environment. We have used X-ray absorption spectroscopy to investigate the coordination sites of arsenic in a wide variety of samples, including soil and earthworm tissues from arsenic-contaminated ...
Arsenic is present in low concentrations in much of the Earth's crust and changes in its speciation are vital to understanding its transport and toxicity in the environment. We have used X-ray absorption spectroscopy to investigate the coordination sites of arsenic in a wide variety of samples, including soil and earthworm tissues from ...
analysis method for extended x-ray absorption fine structure spectroscopy suitable for use with compounds generality and precision are demonstrated in analyses made on two model nanoscale samples: 1 a Ir as the broader utility of the new x-ray absorption spectroscopy based ...
We propose to extend our state-of-the-art, ab initio XAFS (X-ray absorption fine structure) codes, FEFF. Our current work has been highly successful in achieving accurate, user-friendly XAFS standards, exceeding the performance of both tabulated standards and other codes by a considerable margin. We now propose to add the capability to ...
Orientation and charge transfer upon adsorption of thioethanol on copper surface at room temperature has been studied by near edge x-ray absorption fine structure (NEXAFS) and x-ray photoelectron spectroscopy (XPS) techniques. It is found that thioethanol adsorbs dissociatively on the Cu(111) surface. Polarization ...
EXAFS (extended X-ray absorption fine structure) investigations are reported concerning the thermal expansion behaviour of silver in an extended range of temperature from 10 K to about 950 K measured in transmission mode. Both the ratio method and an EXAFS fitting procedure were applied to reveal the temperature dependence of EXAFS ...
The structural properties of Co-doped tris(8-hydroxyquinoline)aluminum (Alq(3)) have been studied by grazing incidence X-ray absorption fine structure (GIXAFS) and Fourier transform infrared spectroscopy (FTIR). GIXAFS analysis suggests that there are multivalent Co-Alq(3) complexes and the doped Co atoms tend to ...
Using extended x-ray-absorption fine-structure (XAFS) spectroscopy we have determined the radii of the first three atomic shells around Ga and the first Pu shell in a fcc Pu alloy stabilized by 1 wt. % Ga. We find the Ga to be substitutional in the fcc lattice, with the first and second shells contracted by 3.7 and 0.9%, respectively, ...
Many metal clusters in the 1-nm size range are catalytically active, and their enhanced reactivity is often attributed to their size, structure, morphology, and details of alloying. Synchrotron sources provide a wide range of opportunities for studying catalysis. Among them, extended X-ray absorption fine-structure (EXAFS) spectroscopy ...
The local environment about oxygen atoms in the CuO{sub 2} plane in YBa{sub 2}Cu{sub 3}O{sub 7} single crystals has been investigated by orientation-dependent x-ray absorption fine structure (XAFS) spectroscopy at the O ls edge using bulk-sensitive fluorescence-yield-detection method. Within experimental accuracy ...
Near edge x-ray absorption fine structure (NEXAFS) spectroscopy at the nitrogen and carbon K-edges was used to study the hydration of adenosine triphosphate in liquid microjets. The total electron yield spectra were recorded as a function of concentration, pH, and the presence of sodium, magnesium, and copper ions ...
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 ...
We have demonstrated the time-resolved measurement of the extended x-ray absorption fine structure (EXAFS) in laser-melted Si foil by using a pump-probe absorption spectroscopy system that utilizes a femtosecond laser-produced-plasma soft x-ray source. By using 100-fs laser irradiation, we ...
Near edge x-ray absorption fine structure (NEXAFS) and infrared reflection-absorption spectroscopy (IRRAS) have been used to study the orientational behavior of thin films of poly(3-methylthiophene) electrochemically polymerized on a platinum surface. Clear orientational effects, with the ...
We describe an advanced setup for time-resolved x-ray absorption fine structure (XAFS) Spectroscopy with picosecond temporal resolution. It combines an intense femtosecond laser source synchronized to the x-ray pulses delivered into the microXAS beamline of the Swiss Light Source (SLS). The setup is applied to ...
Formation of defects in hexagonal boron nitride (h-BN) under low-energy argon or nitrogen ion bombardment has been studied by near-edge X-ray absorption fine structure (NEXAFS) around boron and nitrogen K-edges and X-ray photoemission spectroscopy (XPS) from B1s and N1s core levels. Breaking of B-N bonds and ...
Formation of molecular nitrogen under low-energy nitrogen bombardment of III-V compound semiconductor surfaces has been studied by photoemission spectroscopy around N 1s core-level and near-edge x-ray absorption fine structure (NEXAFS) around N K edge. Interstitial molecular nitrogen N{sub 2} has been formed in all ...
Pressure-induced changes in the local structure about Rb atoms in RbCl are investigated by means of x-ray-absorption fine-structure spectroscopy. Rb K-edge data were taken in fine steps across the pressure-induced NaCl-structure (B1)-to-CsCl-structure(B2)transition at 0.55 GPa. Previous diffraction studies of this phase transition ...
X-ray Absorption Fine Structure (XAFS) spectroscopy was examined, for the first time, as a technique for the determination of elastic strain in thin evaporated films and thin foils. The electron yield and fluorescence yield detection techniques were used to collect the XAFS data. For sensitivity reasons, ...
It has been argued that, in systems that have disorder too large to be described by a Gaussian, x-ray-absorption fine-structure (XAFS) spectroscopy alone cannot define the radial distribution function (RDF) because of the lack of low-{ital k} data. We show that the low-{ital k} data can, under certain conditions, be reconstructed using ...
The inner shell excitation of pyrimidine and some halogenated pyrimidines near the C and N K-edges has been investigated experimentally by near edge x-ray absorption fine structure spectroscopy and theoretically by density functional theory calculations. The selected targets, 5-Br-pyrimidine, 2-Br-pyrimidine, ...
X-ray absorption fine structure spectroscopy has been used to study the chemical and structural properties of self-forming diffusion barrier layers from Cu-8 at. % Mn alloy films on porous low-k and thermally grown SiO2 dielectrics. For the porous low-k/Cu(Mn) system, we provide evidence that the interface is ...
We have measured the near-edge x-ray-absorption fine-structure spectra of the {ital K} edge of potassium in the polymer-salt complex poly(ethylene oxide)-KI. Changes are observed as a function of temperature due to modifications of the K-ion coordination. Comparison with model systems suggests that the lower activation energy of this ionic conducting ...
Bulk amorphous PdCuNiP alloys have been prepared from the liquid state by means of solidification under an argon atmosphere. The addition of a small amount of Fe ({approx}5 at. %) results in the formation of nanocrystalline inclusions inside the residual amorphous matrix. Element-specific near-edge x-ray absorption fine-structure ...
The lattice vibration properties and the boron isotope effect have been studied in YB2 by using temperature-dependent extended x-ray absorption fine structure (EXAFS). The data show anomalous behavior of the Debye-Waller factor of the Y-B pair due to the superposition of an optical mode associated with the boron sublattice and an ...
We have performed a quantitative X-ray absorption fine structure analysis of bacteriorhodopsin in purple membrane patches and in lipidic cubic phases regenerated with Mn(2+). Lipidic cubic phases and purple membrane results have been compared, demonstrating that the lipidic cubic phase process does not introduce relevant distortions in ...
We report on use of cavity ring-down spectroscopy (CRDS) as a means to detect and quantify ion sputtering of refractory metal species. CRDS measurements are made with a neodymium:YAG-pumped optical parametric oscillator laser system in the 375-400 nm region. CRDS sputtering measurements are presented for argon ions incident on iron, aluminum, molybdenum, and titanium. The ...
was founded upon the metals of antiquity, gold (Au), copper (Cu), silver (Ag), lead (Pb), tin (Sn), iron (Fe), and mercury (Hg). Metals were known to the Mesopotamians, Greeks, and Romans. Gold was first discovered about-ray absorption fine-structure (EXAFS) spectroscopy. Her recent interests include the interaction of uranyl
The research activities are summarized here for the following subjects: (1) confinement of block copolymers; (2) free surface confinement; (3) effects of substrate interactions; (4) random copolymers at homopolymer interfaces; (5) phase separation in thin films polymer mixtures; (6) buffing of polymer surfaces; and (6) near edge x-ray absorption fine ...
This report describes the recent synchrotron x-ray absorption fine structure (XAFS) measurements on a number of systems that undergo pressure induced changes in local structure at high pressure. The reader should also refer to the accompanying renewal pro...
We propose to extend our state-of-the-art, ab initio XAFS (X-ray absorption fine structure) codes, FEFF. Our current work has been highly successful in achieving accurate, user-friendly XAFS standards, exceeding the performance of both tabulated standards...
Elucidating the speciation of heavy metals in the environment is paramount to understanding their potential mobility and bioavailability. Cutting-edge synchrotron-based techniques such as microfocused X-ray absorption fine-structure (XAFS) and X-ray fluorescence (XRF) spectroscopy and microtomography have revolutionized the way metal ...
The objective of this study was to elucidate the sorption mechanism of Pb on the high-affinity ruthenium compound with time at pH 6 employing batch methods and X-ray absorption fine structure (XAFS) and X-ray diffraction (XRD) spectroscopies. For the spectroscopic studies, Pb so...
by optical microscopy (OM) and Raman spectroscopy, to identify single layers of graphite and thicker flakes-structure (NEXAFS) spectrum of a single layer of graphite (graphene) obtained by micromechanical cleavage of highly ordered pyrolytic graphite on a SiO2 substrate. We utilized a photoemission electron microscope
Extended X-ray Absorption Fine Structure (EXAFS) experiments impose stringent requirements on a detection system, due to the need for processing ionizing events at a high rate, typically above of 10Mcps/cm2, and with a high resolution, typically better th...
The line positions of all three components of the fluorine atom ground state fine structure transition have been measured by diode laser absorption spectroscopy, using a water vapor pure rotational line at 404.077/cm as a wavelength reference. These resul...
The line positions of two components of the fluorine-atom ground state fine structure transition have been measured with diode laser absorption spectroscopy, using a water vapor pure rotational line at 404.077/cm as a wavelength reference. These results i...
The feasibility of in situ Mossbauer Effect Spectroscopy (MES) and X-Ray Absorption Fine Structure (XFAS) experiments involving transition metal macrocycles adsorbed on high area carbon was demonstrated using mu-oxobis(iron meso-tetrakis(methoxyphenyl) po...
Quick scanning extended x-ray absorption fine-structure spectroscopy is used to obtain in situ structural information on the real-time response of network glasses at the nanoscale level of atomic organization to the temperature ramp through the glass transition range. The results testify nonlinear, real-time temperature response ...
extended X-ray absorption fine structure (NEXAFS); Vanadium oxides 1. Introduction Vanadium sesquioxide, V2O3, is a member of a large vanadium oxide family where the oxidation number of vanadium ranges from, making vanadium oxides interesting both for scientific research and industrial applications. Vanadium
The nanographite grains, the diameter of which was around 5 nm, were formed on Pt(111) by exposing the Pt(111) substrate to benzene gas at room temperature and annealing it up to 850 K. The increase of relative number of edge atoms enabled the observation of edge-derived electronic states. The measurement of ultraviolet photoelectron spectroscopy and near edge x-ray ...
The speciation and mineralogy of sediments contaminated with arsenic at the ground water/surface water interface of the Ft. Devens Super Fund Site in Ft. Devens, MA were determined using X-ray absorption fine structure and X-ray diffraction spectroscopy. Speciation and mineralog...
The principles of experimental methods to study the structure and the hydrogen bonding of hydrated solutes in aqueous solution are presented, and whether theoretical simulations can produce comparable information as the experimental ones is discussed. Two structure methods, extended X-ray absorption fine structure (EXAFS) and large ...
Evidence of a Stable Uranyl Site in Ancient Organic-Rich Calcite S H E L L Y D . K E L L Y , * , E, Stony Brook, New York 11794 The mechanism of uranium (U) incorporation into calcite (calcium carbonate. Extended X-ray absorption fine structure (EXAFS) spectroscopy is uniquely suited to the study of U-calcite
The sorption mechanism of Co on quartz at room temperature has been investigated by an in-depth analysis of published extended X-ray absorption fine structure (EXAFS) spectroscopy and solution chemistry data. In particular, the 3.5-5 mid-range atomic environment of Co has been ...
As the Cs coverage on Ag(111) is increased from approximately 0.15 to 0.3 monolayers the Cs-Ag bond length is found to increase from 3.20 plus or minus 0.03 A to 3.50 plus or minus 0.03 A. The dramatic change is associated with a transition in the caesium...
Quantitative knowledge of the fundamental structure and substrate binding, as well as the direct measurement of conformational changes, are essential to the development of self-assembled monolayers (SAMs) and surface-attached interlocking molecules, caten...
X-ray photoelectron spectroscopy (XPS) and extended x-ray absorption fine structure (EXAFS) studies have been undertaken on sodium disilicate glasses containing varying amounts of Fe sub 2 O sub 3 and UO sub 2 . The XPS results enable one to distinguish t...
Arsenate adsorption on amorphous (RuO2�1.1H2O) and crystalline (RuO2) ruthenium oxides was evaluated using spectroscopic and kinetic methods to elucidate the adsorption mechanism. Extended X-ray absorption fine structure spectroscopy (EXAFS) was ...
Soft X-ray imaging and carbon near edge absorption fine structure spectroscopy (C-NEXAFS) has been used for the in-situ analysis of sporinite in a rank variable suite of organic rich sediments extending from recent up to high volatile A bituminous coal. T...
The effects of alpha irradiation in the rare-earth silicate, Ca2Nd8(SiO4)6O2, was investigated by x-ray diffraction, x-ray absorption near-edge spectroscopy (XANES), and extended x-ray fine structure (EXAFS) techniques. Irradiation with alpha particles em...
Radiative Auger spectra are weak X-ray emission spectra near the characteristic X-ray lines. Radiative Auger process is an intrinsic energy-loss process in an atom when a characteristic X-ray photon is emitted, due to an atomic many-body effect. The energy loss spectra correspond to the unoccupied conduction band structure of materials. Therefore the radiative Auger effect is an alternative tool ...
The performance of a four-element Si drift detector for energy-dispersive fluorescence-yield X-ray absorption fine-structure measurements is reported, operating at the National Institute of Standards and Technology beamline X23A2 at the National Synchrotron Light Source. The detector can acquire X-ray absorption ...
The adsorption of H2S on Ni(001) has been studied with surface-extended x-ray-absorption fine structure and near-edge x-ray-absorption fine structure (NEXAFS) using the AT&T Bell Laboratories X15B beamline at the National Synchrotron Light Source. At 95 K and full ...
With use of fluorescence detection and grazing incidence excitation, the X-ray absorption spectrum was obtained, at the PbL/sub III/ edge, of a monoatomic adlayer of lead on a silver (111) electrode immersed in solution. The adlayer was produced by under potential deposition from aqueous lead acetate/sodium acetate electrolyte. The edge position and the near-edge structure ...
In this thesis the size-dependent optical properties of nanometer-scale semiconductor crystallites (or quantum dots) are investigated. Recently developed synthetic methods are utilized to fabricate a series of high quality, nearly monodisperse, cadmium selenide (CdSe) quantum dots with mean diameters ranging from ~24A to ~105A. Transient differential absorption (TDA), ...
X-ray absorption fine structure (EXAFS) spectroscopy spectra were collected for three brominated persistent pollutants: 6-bromo-2,4,5-trichlorophenol (BrTriClP), pentabromophenol (PentaBrP) and 3,3',5,5'-tetrabromobisphenol A (TBBA). The substances were selected to be symmetrical (BrTriClP and TBBA) or asymmetrical ...
One of the long term research goals has been to attain a quantitative theory of deep core X-ray spectroscopies. These spectroscopies include X-ray absorption fine structure (XAFS), X-ray absorption near edge structure (XANES), X-ray magnetic circular dichroism (XMCD), ...
A new approach to the analysis of x-ray absorption fine structure (XAFS) data is presented. It is based on the use of radial distribution functions directly calculated from a single-particle ion hamiltonian containing model potentials. The starting point ...
A general theory of the fine structure observed on the high-energy side of the K-absorption edge (EXAFS) is presented. The form of the theory presented is useful when the excited atom is not too highly ionized and the potential is approximately sphericall...
A new theory of the extended x-ray-absorption fine structure (EXAFS) is presented which avoids the inaccurate approximations of previous ones. It is shown that, in addition to structure determination, EXAFS gives detailed information on the shielding of t...
... STUDY OF BOND CONSTRAINTS IN GE-SB-TE ALLOYS ... Extended X-ray Absorption Fine Structure Study of Bond Constraints in Ge-Sb-Te Alloys ...
Extended x-ray absorption fine structure (EXAFS) has been used to investigate the metal environment in a number of metallothioneins (MT). In all cases, the primary coordination sphere consists of sulphur atoms. In some cases, evidence for cluster formatio...
The authors have used x-ray absorption to measure the binding energy, x-ray absorption near-edge structure (XANES), and extended x-ray absorption fine structure (EXAFS) of Pt particles in L-zeolite saturated with H{sub 2} at room temperature and after desorption of H{sub 2} in He. The ...
We use the x-ray absorption fine structure spectroscopy at Nb K edge to reveal the local atomic structure of K{sub x}Na{sub 1-x}NbO{sub 3} (PSN) solid solutions. The study is performed over the temperature range 10-1023 K for six different x values. We show that only the combined analysis of extended x-ray ...
The vibrational, electronic, and structural properties of transition-metal macrocycles adsorbed on electrode surfaces are being investigated with an array of in situ spectroscopic techniques. These include potential difference FTIR, electrochemically modulated infrared spectroscopy, EMIRS, electromodulated reflection absorption ...
We demonstrate the feasibility of Near Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy on solids by means of femtosecond soft x-ray pulses from a free-electron laser (FEL). Our experiments, carried out at the Free-Electron Laser at Hamburg (FLASH), used a special sample geometry, spectrographic energy ...
... The fine structure correlates with this absorptive capacity in the following ways: (1) keratin- ization is partial; (2) the lesser degree of keratinization is ...
... TIME, PULSES, RADIATION, SYNCHROTRONS, CONTINUOUS SPECTRA, XENON LAMPS, INTEGRATION, MATERIALS, TARGETS. ...
... This structure is analogous to extended X-ray absorption fine structure (EXAFS), and can be interpreted in terms of interatomic distances in the ...
... SPECTRA, ATOMIC ENERGY LEVELS, ELECTRON TRANSITIONS, SELECTION RULES(PHYSICS), MAGNETIC MOMENTS, DIPOLE MOMENTS ...
... 47 MICRONS OZONE BANDS, WITH CONSIDERATION OF THEIR FINE STRUCTURE-ATMOSPHERIC AND OCEANIC PHYSICS, V5, NO9, P514 ...
... Accession Number : AD0634874. Title : DETERMINATION OF INTERATOMIC DISTANCES FROM X-RAY ABSORPTION FINE STRUCTURE. ...
Strong interstellar absorption lines of C I, arising from the two excited fine-structure levels, are
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The utility of sulfur K-edge X-ray absorption spectroscopy for the determination and quantification of sulfur forms in petroleum asphaltenes has been investigated. Both X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) spectra ...
X-ray absorption methods have been successfully used to obtain quantitative information about local atomic composition of two different materials. X-ray Absorption Near Edge Structure analysis and X-Ray Photoelectron Spectroscopy allowed us to determine seven chemical compounds and their concentrations in c-BN composite. Use of ...
Hexavalent chromium represents higher toxicity in aqueous solutions. It can be removed by such low-cost biosorbents as Sargassum sp. In this study, X-ray absorption fine structure spectroscopy, X-ray photoelectron spectroscopy, and quantum chemistry (QC) calculation were used to study the ...
Chalcogenide glasses have attracted considerable attention and found various applications due to their infrared transparency and other optical properties. The As-S-Se chalcogenide glass, with its large glass-formation domain and favorable nonlinear property, is a promising candidate system for tailoring important optical properties through modification of glass composition. In this context, a ...
The ability of high resolution X-ray spectroscopy to directly probe the grain composition of the ISM is discussed. Using experimental data taken at the National Synchrotron Light Source at Brookhaven National Laboratory and the Advanced Photon Source at Argonne National Laboratory, current and near-future mission prospects for (1) distinguishing gas from dust phase ...
We present a compact setup for near-edge x-ray absorption spectroscopy at the carbon K-edge based on a laser-driven plasma source. Thin polymer films were investigated, showing good agreement with corresponding synchrotron data. Furthermore we have examined the carbon near-edge structure of phospholipids and fulvic acids, providing detailed information on ...
In this letter, we have used the extended x-ray-absorption fine-structure (EXAFS) technique to investigate the structure of Mn-rich self-organized nanocolumns grown by low temperature molecular beam epitaxy. The EXAFS analysis has shown that Mn-rich nanocolumns exhibit a complex local structure that cannot be described by a simple substitutional model. ...
We report orientation-specific, surface-sensitive structural characterization of colloidal CdSe nanorods with extended X-ray absorption fine structure spectroscopy and ab-initio density functional theory calculations. Our measurements of crystallographically-aligned CdSe nanorods show that they have reconstructed ...
A particle-in-a-box approximation to the problem of x-ray absorption fine structure has been successful in predicting many features of the effect. The theory successfully accounts for the extended fine structure observed on any x-ray absorption edge in cr...
NRMRL-RTP-P-646 Shoji, T., Huggins, F.E., Huffman, G.P., Linak*, W.P., and Miller*, C.A. XFAS Spectroscopy Analysis of Selected HAP Elements in Fine PM Derived from Coal Combustion. Energy and Fuels 16 (2): (2002). 11/30/2001 X-ray absorption fine structure (XAFS) spectroscop...
The past several years have witnessed the emergence of Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy from an esoteric technique to a widely available structural spectroscopic tool. Several in-depth review articles and books are available on the subject, but some aspects of theory or data reduction ...
Two heme iron enzymes, oxygenated chloroperoxidase and cytochrome P-450-CAM, have been characterized using extended X-ray absorption fine structure spectroscopy (EXAFS). The EXAFS spectra of the two compounds are identical within the spectral noise. Curve filling has lead to the conclusion that both enzymes have an ...
The broad spectral distribution (x-ray to infrared), high intensity, and time and polarization structure of synchrotron radiation (SR) make it an attractive light source for many applications. A stable source of high-energy SR is SPEAR. Some of the applications of SR discussed are in x-ray absorption spectroscopy (fine ...
The inner shell excitation and ionisation of pyrimidine have been studied at the carbon K edge by near-edge X ray absorption fine structure (NEXAFS) and X ray photoelectron (XPS) spectroscopies. The theoretical predictions of density functional theory (DFT) provide a satisfactory assignment of the complex spectra ...
Extended x-ray absorption fine structure (EXAFS) spectroscopy has been used to determine the structural environment local to iron(HI) and zircorium(IV) cations in respectively, nanoscale iron oxyhydroxide and nanoscale zirconium oxide powders. The iron oxyhydroxide powder, produced by the modified reverse micelle ...
Extended X-ray absorption fine structure (EXAFS) backscattering amplitude and phase functions have been calculated from first principles for K and L edges for nearly every element in the periodic table by using a full curved wave formalism. These functions are tabulated for approximately half of the elements from boron through ...
Peridinin-chlorophyll a protein (PCP) is a unique water soluble antenna complex that employs the carotenoid peridinin as the main light-harvesting pigment. In the present study the near edge X-ray absorption fine structure (NEXAFS) spectrum of PCP was recorded at the carbon K-edge. Additionally, the NEXAFS spectra of the constituent ...
The chemical form of Ag in the livers of five species of marine mammals was examined using X-ray absorption fine structure (XAFS) and X-ray fluorescence (XRF) spectroscopies. The XAFS analysis suggested that Ag(2)Se was present in the livers of the Franciscana dolphin (Pontoporia blainvillei), Dall's porpoise ...
Near-edge x-ray absorption fine structure spectroscopy (NEXAFS) is a powerful tool for determination of molecular orientation in self-assembled monolayers and other surface-attached molecules. A general framework for using NEXAFS to simultaneously determine molecular tilt and twist of rigid molecules attached to ...
In order to understand the evolving world of environmental issues, the ability to characterize and predict the stability and bioavailability of heavy m�tal contaminants in mine waste is becoming increasingly more important. X-ray Absorption Near Edge Structure (XANES) and Extended X-ray Absorption Fine Structure ...
X-ray absorption spectroscopy was used to determine the local structure of U(VI) within synthetic fluorapatite at a concentration of 2.3 wt %. Extended X-ray absorption fine structure indicates that U(VI) substitutes into the Ca1 site. To accommodate this substitution the apatite structure ...
The nitrate complexes of Pu(IV) are studied in solutions containing nitrate at concentrations up to 13 molar (M) using absorption spectroscopy, N-15 nuclear magnetic resonance (NMR), and extended X-ray absorption fine structure (EXAFS). Four major nitrato complexes are observed and identified ...
Recent developments in the understanding of the biosynthesis of the active site of the nitrogenase enzyme, the structure of the iron centre of [Fe]-hydrogenase and the structure and biomimetic chemistry of the [FeFe] hydrogenase H-cluster as deduced by application of X-ray spectroscopy are reviewed. The techniques central to this work include X-ray ...
Elucidation of the inorganic materials within coals is important for coal processing, since these compounds may function as in situ catalysts for coal liquefaction. In addition, these species will have to be separated from the organic species prior to the use of coal as a fuel or chemical feedstock. In recent years, x-ray absorption spectroscopy (XAS) has ...
Absorption measurements above the K edges of the low-Z atoms, C, N, O, and F, are discussed, which utilize 250--1000-eV synchrotron radiation. The paper emphasizes experimental procedures of soft x-ray absorption and extended absorption fine structure (EXAFS) measurements as well as ...
The fine structure of the K absorption spectra of nickel and iron in Ni- Fe alloys was studied. The results are given relative to the displacements of the Ki points of the principal discontinuities and of the maxima and minima of the fine structure determined by the variation of the ...
... resonance (EPR), and (7)Li solid state nuclear magnetic resonance (NMR ... extended x-ray absorption fine structure shows that the local symmetry of ...
... Accession Number : AD0693193. Title : POINT SCATTERING THEORY OF X-RAY K-ABSORPTION FINE STRUCTURE,. ...
We report on Mn K-edge X-ray absorption study, in plane and out of plane, of La0.7Sr0.3MnO3 films, epitaxially grown on a tensile substrate SrTiO3 by laser ablation. From Extended X-ray Absorption Fine Structure in the film plane we observe a small increase of Mn-Mn distances with respect to relaxed film. In ...
Automation of x-ray absorption spectroscopic (XAS) data reduction is essential to cope with high-throughput data collection becoming available at an increasing number of synchrotron radiation centers. A flexible script called KEMP has been developed and implemented at the XAS beamline at EMBL Hamburg. It automatically processes fluorescence XAS data. The pipeline includes dead ...
Surface segregation of end-functional poly(2-vinylpyridine) in a blend with P2VP was measured by X-ray photoelectron spectroscopy. A series of chain end functionalized P2VP homopolymers were synthesized via either anionic polymerization or Reversible Addition Fragmentation Chain Transfer (RAFT) and end capped with either a single fluorinated oligomer or a perfluorinated ...
In this work we employ the state of the art pseudopotential method, within a generalized gradient approximation to the density functional theory, to investigate the adsorption process of furan on the silicon (001) surface. A direct comparison of different adsorption structures with x-ray photoelectron spectroscopy (XPS), ultra-violet photoelectron ...
We analyze gold nanoclusters as supported catalysts by extended X-ray absorption fine structure, X-ray diffraction and X-ray photoelectron spectroscopy in order to determine their local, global and electronic structure. The present study points out a strong deformation of the local structure of the metal due to its ...
This study addresses the need for methods that validate the surface chemistry leading to the immobilization of biomolecules and provide information about the resulting structural configurations. We report on the use of near edge x-ray absorption fine structure spectroscopy (NEXAFS) to characterize a widely employed ...
The sensitivity of near-edge X-ray absorption fine structure (NEXAFS) to differences in key chemical components of polyurethane polymers is presented. Carbon is NEXAFS spectra of polyurethane polymers made from 4,4{prime}-methylene di-p-phenylene isocyanate (MDI) and toluene diisocyanate (TDI) isocyanate monomers illustrate that there ...
Extended x-ray-absorption fine-structure spectroscopy (EXAFS) has been used to determine the position of Zr within the unit cell of Sm{sub 2}Co{sub 17}. Induction-melted Sm{sub 2}Co{sub 17}:Zr ternary alloys, aged at 1180 {degree}C, then quenched, consisted of intimately mixed H2:17 and R2:17 having Zr in solid solution as well some ...
X-ray absorption fine structure (XAFS) spectroscopy has been employed to investigate the cation distribution in nanocrystalline zinc ferrites (ZnFe(2)O(4)), synthesized in acidic and basic media at different temperatures. By using (Zn(1-x)Fe(x))[Ni(x)Fe(2-x)]O(4) as model compounds we have determined cation ...
Techniques were developed for application of lasers to two fundamental experiments in atomic spectroscopy: Fine structure of positronium n = 2 state; Vibrational spectrum of the hydrogen molecular ion HD(+). (Author)
