Time Resolved X-Ray Absorption Spectroscopy 2006. 10. 16 Lee, Youhong TR-XAS #12;LITR-XAS � Laser-Initiated Time-Resolved X-ray Absorption Spectroscopy TR-XAS #12;� Beer's law TR-XAS I0 I 0 exp( ) I x I = - : ...
E-print Network
... Synchrotron radiation-excited photoemission spectroscopy and x-ray absorption spectroscopy (XAS ... of the C, N and F K-edge electronic structure of ...
DTIC Science & Technology
... SOLUTIONS(MIXTURES), DYNAMICS, PHASE, CLUSTERING, MOLECULAR STRUCTURE, ELECTROLYTES, X RAY SPECTROSCOPY. ...
Electron paramagnetic resonance (EPR) and x-ray absorption spectroscopy (XAS) were used as probes of the manganese atoms of the oxygen evolving complex (OEC). XAS studies at liquid helium temperatures allowed the observation of a scatterer at >3 (angstrom...
National Technical Information Service (NTIS)
for Li-ion batteries and supercapacitors using synchrotron based in situ X-ray absorption spectroscopy (XAS) and X-ray diffraction (XRD). - Studies on thermal decomposition...
Science.gov Websites
... device (SQUID) magnetometry, x-ray absorption spectroscopy (XAS) and magnetic circular dichroism (MCD). ... 3c, confirming that the dichroism, ...
... Title : Chemical Phase and Valence Studies of Plasma Sprayed Coatings: EDXRD and X-ray Absorption Spectroscopy (XAS) Results. ...
to a variety of techniques including x-ray diffraction (XRD), scanning-transmission electron microscopy (STEM), and x-ray absorption spectroscopy (XAS). The combination of...
In this study, oriented Photosystem II (PS II) particles from spinach chloroplasts are studied with electron paramagnetic resonance (EPR) and x-ray absorption spectroscopy (XAS) to determine more details of the structure of the oxygen evolving complex (OE...
The manganese sites in chloroplasts, long thought to be involved in photosynthetic oxygen evolution have been examined and partially characterized by x-ray Absorption Spectroscopy (XAS) using synchrotron radiation. The local environment about the manganes...
The ability of an individual H(sub 2)O molecule to form multiple hydrogen bonds with neighboring molecules makes it an ideal substance for the study of hydrogen bonding. X-ray absorption spectroscopy (XAS) can be used to study what intermolecular structur...
Our experimental program utilizes x-ray absorption spectroscopy (XAS) to study metal-containing chemical systems, such as metal electrolyte solutions, metal complexes and metal cluster systems. Objectives include the direct experimental measurement of che...
We present herein the current status of the X-ray Absorption Spectroscopy (XAS) Beamline at the 3 GeV Australian Synchrotron. The optical design and performance, details of the insertion device (Wiggler), end station capabilities and construction and commissioning timeline are given.
Energy Citations Database
X-ray absorption spectroscopy (XAS) is a useful tool for studying nanoparticle synthesis and growth. Described here is a system for automating synthesis and data collection, allowing time-resolved XAS measurements at a synchrotron to be accurately combined with measurements made under identical conditions ...
X-ray absorption spectroscopy (XAS) is an ideal technique for the investigation of the local structure in materials and in particular around dopant species in semiconducting crystals. This experimental technique permits the quantitative determination of structural parameters such as the bond distances and number of neighbors that are ...
NASA Astrophysics Data System (ADS)
The combination of in situ X-ray diffraction (XRD) and x-ray absorption spectroscopy (XAS) is a very powerful technique in the study of lithium battery cathode materials. XRD identifies the phase changes that occur during cycling and XAS gives information on the redox charge compensation processes that occur on the ...
DOE Information Bridge
X-Ray Absorption Spectroscopy (XAS) and Photoelectron Spectroscopy (PES) have been performed upon highly radioactive samples, particularly Plutonium, at the Advanced Light Source in Berkeley, CA, USA. First results from alpha and delta Plutonium are reported as well as a detailed analysis of sample quality. ...
X-Ray Absorption Spectroscopy (XAS) and Photoelectron Spectroscopy (PES) have been performed upon highly radioactive samples, particularly Plutonium, at the Advanced Light Source in Berkeley, CA, USA. First results from alpha and delta Plutonium are reported as well as a detailed analysis of sample quality.
An x-ray absorption spectroscopy (XAS) investigation of the structural changes occurred upon hydriding in the Friauf-Laves phase compounds CeFe(sub 2), CeRu(sub 2)and LaRu(sub 2) compounds is presented. The analysis of the extended x-ray absorption spectr...
A versatile instrument for glancing-angle X-ray absorption spectroscopy (XAS) and X-ray reflectivity in routine use on the Daresbury Synchrotron Radiation Source is described. The facility can be used for XAS measurements in both reflectivity and fluoresc...
After the CMMD Seminar by Sung Woo Yu on the subject of the x-ray spectroscopy of UO2, there arose some questions concerning the XAS of UO2. These questions can be distilled down to these three issues: (1) The validity of the data; (2) The monchromator energy calibration; and (3) The validity of XAS component of the figure shown. The ...
never been directly measured. We approach this problem using ultrafast X-ray absorption spectroscopy femtosecond transient absorption spectroscopy and the results are summarized in Figure 1c.11,37,38 Here we of the detector. The spectral data are collected from 7017 to 7624 eV in steps of 4 eV. Transient ...
This paper demonstrates the use of soft X-ray absorption spectroscopy (XAS) and two-dimensional (2D) correlation spectroscopy in the investigation of the mechanism of solid electrolyte interface (SEI) formation in the Li1+xV3O8 electrode surface during the first lithium insertion extraction cycle in a Li1+xV3O8/Li ...
Synchrotron-based X-ray absorption spectroscopy (XAS) of select surface soil samples obtained from Camp Edwards, Massachusetts, small arms ranges indicate that little tungsten metal remains in the soil and that is not stable in the natural environment. X-...
The application of X-ray Absorption Spectroscopy (XAS) to the study of diffusion properties of oxide glasses and glass surfaces is considered. Mixed alkali silicates are discussed, as are the chemical resistance of iron-lead-phosphate glasses and the surf...
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 ...
Fluorescent-yield X-ray absorption spectroscopy (XAS) taken with a superconducting tunnel junction (STJ) detector has been employed to study the oxygen K-edge structure of Hf Al oxide gate insulators for next-generation metal-oxide-semiconductor (MOS) devices. Thermal stability is a critical issue in the MOS fabrication processes. We ...
Copper (Cu) metallothioneins are cuprous-thiolate proteins that contain multimetallic clusters, and are thought to have dual functions of Cu storage and Cu detoxification. We have used a combination of X-ray absorption spectroscopy (XAS) and density-functional theory (DFT) to investigate the nature of Cu binding to Saccharomyces ...
Systematic Mn K-edge x-ray absorption spectroscopy (XAS) measurements on samples of La(sub 1(minus)x)Sr(sub x)MnO(sub 3), which are precursors to colossal magnetoresistive (CMR) materials, are reported. Detailed results on the edge or chemical shift as a ...
It is presented an x-ray absorption spectroscopy (XAS) investigation performed at the L-edges of the rare-earth and at the K-edge of iron in the R-Fe intermetallic compounds (La, Ce)(sub 2)Fe(sub 14)BH(sub (chi)) and Ce(sub 2)Fe(sub 17)(H, N)(sub (chi)), ...
ID24 is the energy dispersive beamline of the European Synchrotron Radiation Facility dedicated to X-ray Absorption Spectroscopy (XAS). Since 2000, a complete refurbishment program has started, including source upgrade, mirrors replacement, polychromator optimization and detection improvements. These have made possible the development ...
Bm29 and ID24 are two complementary beamlines of the European Synchrotron Radiation Facility dedicated to X-ray Absorption Spectroscopy. BM29 is a standard energy scanning XAS beamline with a bending magnet X-ray source, while ID24 has an energy dispersive set-up with an undulator source. This paper describes the setup and the actual ...
The combination of in situ X-ray diffraction (XRD) and x-ray absorption spectroscopy (XAS) is a very powerful technique in the study of lithium battery cathode materials. XRD identifies the phase changes that occur during cycling and XAS gives information...
The association of copper to Riboflavin Binding Protein (RBP) from egg white has been studied by electron paramagnetic resonance (EPR) and X-ray absorption (XAS) spectroscopies. The type II site contains a mix of copper I and II in an oxygen rich environment.
PubMed Central
Arsenic in soils from the Asarco lead smelter in East Helena, Montana was characterized by X-ray absorption spectroscopy (XAS). Arsenic oxidation state and mineralogy were analyzed as a function of depth and surface distribution using bulk and microprobe XAS. These results were c...
EPA Science Inventory
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 ...
A software package for the analysis of X-ray absorption spectroscopy (XAS) data is presented. This package is based on the IFEFFIT library of numerical and XAS algorithms and is written in the Perl programming language using the Perl/Tk graphics toolkit. The programs described here are: (i) ATHENA, a program for ...
X-ray Absorption Spectroscopy (XAS) of the Rare Earth (RE) 3d levels yields sharp peaks near the edges as a result of strong, quasi-atomic 3d(sup 10)4f(sup n) (yields) 3d-(sup 9)4f(sup n+1) transitions and these transitions exhibit a wealth of spectroscop...
X-ray absorption spectroscopy (XAS) is proving invaluable in determining the average chemical form of metals or metalloids in intact biological tissues. As most tissues have spatial structure, there is great additional interest in visualizing the spatial location of the metal(loid) as well as its chemical forms. ...
Inverse partial fluorescence yield (IPFY) is a newly developed x-ray absorption spectroscopy (XAS) that utilizes non-resonant emission processes to measure the x- ray absorption of a material. Unlike XAS by traditional transmission, total electron yield and total fluorescence yield, IPFY is ...
X-ray absorption spectroscopy (XAS) is a useful tool for obtaining structural and chemical information about the active sites of metalloproteins and metalloenzymes. Information may be obtained from both the edge region and the extended X-ray absorption fi...
High energy resolution fluorescence detection (HERFD) X-ray adsorption spectroscopy (XAS) is demonstrated as a new tool to identify the geometry of metal adsorption sites and the orbitals involved in bonding. The type of CO adsorption site on a nanoparticular Pt-Al2O3 catalyst is determined. The orbitals involved in the Pt - CO bonding are identified using ...
Synchrotron radiation from the Advanced Light Source has been used to investigate the electronic structure of {alpha}-Pu and {delta}-Pu. Measurements include core level and valence band photoelectron spectroscopy, Resonant Photoelectron Spectroscopy (REPES), and X-ray Absorption Spectroscopy ...
The present status of in-situ scanning transmission X-ray microscopy (STXM) is reviewed, with an emphasis on the abilities of the STXM technique in comparison with electron microscopy. The experimental aspects and interpretation of X-ray absorption spectroscopy (XAS) are briefly introduced and the experimental boundary conditions that ...
PubMed
Examination of the adsorption mechanism of Tl and Cr on selected mineral oxides was carried out by X-ray Absorption Spectroscopy (XAS) using synchrotron radiation. Information on the oxidation states of surface bound species was obtained from the low energy side of XAS spectra, the XANES (X-ray ...
X-ray Absorption Spectroscopy (XAS) of the Rare Earth (RE) 3d levels yields sharp peaks near the edges as a result of strong, quasi-atomic 3d{sup 10}4f{sup n} {yields} 3d-{sup 9}4f{sup n+1} transitions and these transitions exhibit a wealth of spectroscopic features. The XAS measurements of single crystal REPO{sub ...
X-ray absorption spectroscopy (XAS) has been used to unveil the bromide ion local coordination structure in 1-alkyl-3-methylimidazolium bromide [C(n)mim]Br ionic liquids (ILs) with different alkyl chains. The XAS spectrum of 1-ethyl-3-methylimidazolium bromide has been found to be different from those of the other ...
We present soft x-ray absorption spectroscopy (XAS) on spinel manganites and show it can be used as a powerful tool to directly probe the Jahn-Teller (JT) splitting energy in transition metal oxides. The Mn L2,3-edge XAS spectra of the spinel ZnMnxGa2-xO4 (x=0.5,1.0,1.4, and 2.0) and AMn2O4 (A=Mg and Cd) change ...
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 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 ...
X-ray absorption spectroscopy (XAS) was used to study the arsenic fluorocomplexes, including the AsF sub 5 and AsF sub 6- intercalates of graphite, and rubidium metal-ammonia solutions. The As-F distances obtained for AsF sub 3 and AsF sub 5 gas are both ...
An analysis of the valence and conduction band electronic structure of TiO2 as studied by ultraviolet photoemission spectroscopy UPS and x-ray absorption spectroscopy XAS using synchrotron radiation is reported. Valence band spectra from UPS have been dec...
Synchrotron-radiation-based spectroscopies such as X-ray Absorption Spectroscopy (XAS) have contributed greatly to our improved understanding of Pu electronic structure. However, significant questions remain concerning the nature of Pu electronic structure. Perhaps the missing piece of the puzzle is the direct ...
The objective of this research was to design and construct a bending magnet beamline at the Advanced Photon Source. The beamline is to be optimized for x-ray absorption spectroscopy (XAS) studies with a major focus on environmental issues. The beamline will share the experimental facilities under development at the neighboring ...
Design and construction of a bending magnet beamline at the Advanced Photon Source (APS) by the Pacific Northwest Consortium-Collaborative Access Team (PNCCAT). The beamline will be optimized for x-ray absorption spectroscopy (XAS) studies with a major focus on environmental issues. The beamline will share the experimental facilities ...
Single-crystal X-ray absorption spectroscopy (XAS) instrumentation, allowing sequential integrated XAS and crystallographic data acquisition during the same experiment and on the same beamline, has been developed for SSRL beamline 9-3, a wiggler side station dedicated to general user biological ...
ID24 is the energy dispersive beamline of the European Synchrotron Radiation Facility dedicated to X-ray Absorption Spectroscopy (XAS). Thanks to the parallel acquisition mode that allows data in a large energy range to be collected simultaneously, XAS using dispersive optics is particularly suited for the study of ...
The fern Pteris vittata accumulates unusually high levels of arsenic. Using X-ray absorption spectroscopy (XAS) and XAS imaging, we reveal the distribution of arsenic species in vivo. Arsenate is transported through the vascular tissue from the roots to the fronds (leaves), where it is reduced to arsenite and ...
Investigation of the local structure of the high-temperature liquid and solid phases in the 300-725 K range of AgBr has been performed using the x-ray absorption spectroscopy (XAS). Structural results are compared with existing diffraction studies and computer simulations demonstrating the reliability of the XAS ...
A survey over X-ray absorption methods in homogeneous catalysis research is given with the example of the iron-catalyzed Michael addition reaction. A thorough investigation of the catalytic cycle was possible by combination of conventional X-ray absorption spectroscopy (XAS), resonant inelastic X-ray scattering ...
Metal mobility in subsurface water systems involves the complex interaction of the metal, the fluid, and the mineral surfaces over which the fluid flows. This mobility is further influenced by metal adsorption onto bacteria and other biomass in the subsurface. To better understand the mechanism of this adsorption as well as its dependence on the chemical composition of the fluid, we have performed ...
Microorganisms release organic macromolecules, such as siderophores, to obtain Fe(III) from natural systems. While the relative stabilities of Fe(III)-siderophore complexes are well-studied, the structural environments of Fe(III) and ligands in the complex are not well-understood. Using the X-ray absorption spectroscopy (XAS) at the ...
LiFePO4 composite was synthesized by both solid state and hydrothermal methods. The physical properties of the as-prepared lithium iron phosphates were characterized by X-ray diffraction while electrochemical properties were measured with charge/discharge experiments. X-ray absorption spectroscopy (XAS) was performed to investigate the ...
We present systematic investigations of the electronic and magnetic properties of the graphene/Ni(111) system by means of x-ray absorption spectroscopy (XAS) and magnetic circular dichroism (XMCD) at the Ni L2,3 and C K absorption edges. The XAS C 1s-->?*,?* spectra show dramatic changes as ...
Using photoemission electron microscopy, we have measured x-ray absorption (XAS) and x-ray magnetic circular dichroism (XMCD) spectra of single, three-dimensional iron nanoparticles in the size range 6-25 nm. We discuss the feasibility and limits of single-particle XAS and XMCD spectroscopy, in particular the ...
The catalytic partial oxidation of methane to synthesis gas over ruthenium catalysts was investigated by thermogravimetry coupled with infrared spectroscopy (TGA-FTIR) and in situ X-ray absorption spectroscopy (XAS). It was found that the oxidation state of the catalyst influences the product formation. On oxidized ...
We describe the use of a flow-focusing microfluidic reactorto measure the kinetics of theCdSe-to-Ag2Se nanocrystal cation exchangereaction using micro-X-ray absorption spectroscopy (mu XAS). The smallmicroreactor dimensions facilitate the millisecond mixing of CdSenanocrystal and Ag+ reactant solutions, and the transposition of ...
The chemical nature of the sulfur in bacterial sulfur globules has been the subject of controversy for a number of years. Sulfur K-edge X-ray absorption spectroscopy (XAS) is a powerful technique for probing the chemical forms of sulfur in situ, but two groups have used it with very different conclusions. The root of the controversy ...
We investigated different AlN nano-systems using spectroscopic methods. Experiments were performed at the Synchrotron Radiation Facility of the Laboratori Nazionali di Frascati using both XANES (x-ray absorption near edge spectroscopy) and FTIR (Fourier transform infrared spectroscopy) techniques in order to investigate materials with ...
The electronic structure of TiO2 nanosheets on the Pt(110)-(1 � 2) surface has been investigated by using high resolution photoemission spectroscopy and x-ray absorption spectroscopy (XAS). The Ti 2p XAS spectra of the deposited TiO2 films have been theoretically evaluated and, from the ...
The electronic structure of TiO(2) nanosheets on the Pt(110)-(1 � 2) surface has been investigated by using high resolution photoemission spectroscopy and x-ray absorption spectroscopy (XAS). The Ti 2p XAS spectra of the deposited TiO(2) films have been theoretically evaluated and, from the ...
The reaction of bovine serum albumin (BSA) with [ trans-RuCl 4(Im)(dimethylsulfoxide)][ImH] (Im = imidazole) (NAMI-A), an experimental ruthenium(III) anticancer drug, and the formation of the respective NAMI-A/BSA adduct were investigated by X-ray absorption spectroscopy (XAS) at the sulfur and chlorine K-edges and at the ruthenium K- ...
We study the importance of inter-site coherences and quantum interference effects in the X-ray absorption spectroscopy (XAS) of mixed-valent systems. We demonstrate its importance, first for a simple diatomic mixed-valent molecule to elucidate the physics involved, and finally for mixed-valent Ti oxides, using a model calculation ...
Quantification of the initial rates of environmental reactions at the mineral/water interface is a fundamental prerequisite to determining reaction mechanisms and contaminant transport modeling and predicting environmental risk. Until recently, experimental techniques with adequate time resolution and elemental sensitivity to measure initial rates of the wide variety of environmental reactions ...
The electronic structures of SrMn1-xRuxO3 (0<=x<=1) have been investigated by employing soft x-ray absorption spectroscopy (XAS). The measured Mn 2p XAS spectra for SrMn1-xRuxO3 show that the valence states of Mn ions change monotonically from Mn4+ for x=0 to ~Mn3+ for x=0.8, suggesting that the valence ...
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 measure the short-lived ...
... Accession Number : AD0442491. Title : OPTICAL ABSORPTION AND PHOTOLUMINESCENCE OF DOPED GAAS AND (INXGA1-X)AS,. ...
A new type of layer compound, CrPS4, has been investigated by means of reflection electron-energy-loss spectroscopy (REELS), x-ray-absorption spectroscopy (XAS), and x-ray photoelectron spectroscopy (XPS). Information on the bonding states of the compositional atoms and the occupied energy ...
In this work, in-situ x-ray absorption spectroscopy (XAS) measurements of the ion concentrations within an artificial pit are presented to study the ionic species present and mass transport phenomena during localized corrosion taking place on metal surfaces. The x-ray absorption by an element in a sample is ...
We describe the chemical information that can be obtained by means of hard X-ray emission spectroscopy (XES). XES is presented as a technique that is complementary to X-ray absorption spectroscopy (XAS) and that provides valuable information with respect to the electronic structure (local charge- and spin-density) ...
Brominated powdered activated carbon sorbents have been shown to e quite effective for mercury capture when injected into the flue gas duct at coal-fired power plants and are especially useful when buring Western low-chlorine subbituminous coals. X-ray absorption spectroscopy (X...
, the structures are not resolved at the atomic level. X-ray absorption (XAS), emission (XES), resonant inelastic X-ray-edge structure (XANES) and Kb X-ray emission spectra (XES) for elements in the first transition-metal series X-ray spectra for transition elements like Mn, Fe and Mo, as well as for Ca, Sr, S, Se, Cl and Br
Ligand K-edge X-ray absorption spectroscopy (XAS) has been developed as a technique for the investigation of ligand-metal bonding and has been applied to the study of electronic structure in organic model complexes and metalloprotein active sites. Ligand ...
The sorption and desorption of Pb on RuO2 xH2O were examined kinetically and thermodynamically via spectroscopic and macroscopic investigations. X-ray absorption spectroscopy (XAS) was employed to determine the sorption mechanism with regard to identity of nearest atomic neighbo...
Design and construction of a bending magnet beamline at the Advanced Photon Source (APS) by the Pacific Northwest Consortium-Collaborative Access Team (PNC-CAT). The beamline will be optimized for x-ray absorption spectroscopy (XAS) studies with a major focus on environmental iss...
X-ray absorption spectroscopy (XAS) has been used at extensively at Brookhaven National Laboratory (BNL) to study materials and electrodes of several battery systems. The power and the general applicability of the technique is illustrated by studies of several battery materials such as PEO-salt complexes, PbO{sub 2}, and in situ ...
X-ray absorption spectroscopy (XAS) was used extensively at Brookhaven National Laboratory (BNL) to study materials and electrodes of several battery systems. The power and the general applicability of the technique is illustrated by studies of several battery materials such as PEO-salt complexes, PbO2, and in situ studies of mossy ...
Arsenic in soils from the Asarco Lead Smelter in East Helena, Montana was characterized by X-ray absorption spectroscopy (XAS). As oxidation state and geochemical speciation were analyzed as a function of depth (two sampling sites) and surface distribution. These results were c...
Design and construction of a bending magnet beamline at the Advanced Photon Source (APS) by the Pacific Northwest Consortium-Collaborative Access Team (PNC-CAT). The beamline will be optimized for x-ray absorption spectroscopy (XAS) studies with a major f...
The speciation and distribution of cobalt (Co) in soils is poorly understood. This study was conducted using X-ray absorption spectroscopy (XAS) techniques to examine the influence of soluble Co(II) aging, submergence-dried cycling, and the presence of in vivo rice roots on the...
Transformation of Cd species can occur in response to fluctuating soil moisture conditions. Redox potential is a master variable controlling Cd speciation and bioavailability in paddy soils, and soil pH influences the transport and fate of Cd (e.g., via sorption to organic matter or metal oxides an...
Technology Transfer Automated Retrieval System (TEKTRAN)
The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...
The ESRF has recently started an ambitious project spread over 10 years aimed at an upgrade of the accelerator, beamlines and infrastructure. Through this upgrade, we are proposing a refurbishment of the scanning EXAFS beamline BM29 and of the Energy Dispersive XAS (EDXAS) beamline ID24.
A bending magnet beamline has been constructed and commissioned for x-ray absorption spectroscopy (XAS) at the Siam Photon Laboratory. The photon energy is tunable from 1830 eV to 8000 eV using a Lemmonier-type, fixed-exit double crystal monochromator equipped with InSb(111), Si(111), Ge(220) crystals. Elemental K-edges are then ...
Ti K edge X-ray absorption spectroscopy (XAS) was applied to determine the Ti co-ordination environment in the surface amorphised layer formed on zirconolite ceramics by 2 MeV Kr+ irradiation, to a fluence of 5 � 1015 ions cm?2. The application of XAS in a grazing angle geometry was demonstrated to be essential ...
M�ssbauer spectroscopy and X-ray absorption spectroscopy (XAS) have been used to obtain information on the redox and coordination of iron in glasses made by the vitrification of simulated and actual sewage sludge combustion ashes. M�ssbauer spectra have been deconvoluted using three extended Voigt-based ...
The local structure of vanadium oxide supported on nanostructured SiO2 (VxOy/SBA-15) was investigated by in situ X-ray absorption spectroscopy (XAS). Because the number of potential parameters in XAS data analysis often exceeds the number of "independent" parameters, evaluating the reliability and significance of a ...
The association of copper to Riboflavin Binding Protein (RBP) from egg white has been studied by electron paramagnetic resonance (EPR) and X-ray absorption (XAS) spectroscopies. The type II site contains a mix of copper I and II in an oxygen rich environment. The association of copper to Riboflavin Binding Protein (RBP) from egg white ...
We report here the atomic force microscopy (AFM) and x-ray absorption spectroscopy (XAS) measurements of epitaxial LaNiO3 thin films deposited on LaAlO3 (001) single crystals. AFM study reveals the uniform growth of deposited film. XAS spectra of Ni L3,2 edge confirms the 3+ charge state of Ni in LaNiO3 film and ...
We have performed x-ray absorption spectroscopy (XAS) measurements on Zn1-2xMnxCoxO nanoparticles. From the XAS results, it seems that the Mn and Co ions are in a mixed-valence (2+, 3+, and 4+) state and the relative concentrations of the high-valence (3+ and 4+) Mn and Co ions are higher in the surface region than ...
We report on the room temperature ferromagnetism in the swift heavy ion (SHI) irradiated TiO2 thin films by x-ray absorption spectroscopy (XAS) and x-ray magnetic circular dichroism (XMCD) experiments at the O K and Ti L3,2 absorption edges. The XAS/XMCD measurements provide direct evidence of ...
Gold clusters supported on Al2O3 and TiO2 have been exposed to different mixtures of CO and O2. Their structure has been probed in situ using X-ray absorption spectroscopy (XAS) at the Au L3-edge. In all materials, the dominant phase during catalysis is Au0. Both samples show variations of the electronic structure of the gold clusters ...
Motivated by an ex situ TEM-investigation on the internal reduction of (Mg{sub 1-x}Cu{sub x})O [1], we have performed a XAS analysis on the precipitation formation in (Mg{sub 1-x}Cu{sub x})O after exposing the specimen to a{sub o2} = 6x10{sup -12} for several hours. As the reduction rate is slow, a detailed characterization of the reaction path was elaborated for ...
Tin dioxide (SnO2) thin films were deposited on a well cleaned sapphire single crystal substrate by rf magnetron sputtering technique. After deposition, films were irradiated by swift heavy ion (SHI) irradiation at various ion fluences. We present the X-ray absorption spectra (XAS) at the oxygen K- and Sn M5,4, edge. The XAS pattern ...
Since 1990 there has been an ongoing collaboration among the authors to investigate the role of individual elements on the thermodynamics and kinetics of hydriding/dehydriding reactions. This review article presents the electrochemical and physicochemical characteristics of hydriding/dehydriding reactions from the point of view of their dependence on electronic, geometric and surface properties of ...
We identify a mechanism responsible for amorphization of rare-earth molybdate isostructural compounds by means of x-ray absorption spectroscopy (XAS) and Raman spectroscopy as well as first-principles calculations. Our present Raman spectra show that both ?' and ?-Eu2(MoO4)3 undergo a pressure-induced ...
Valuable information on the active sites of molybdenum enzymes has been provided from both Mo(V) electron paramagnetic resonance (EPR) spectroscopy and X-ray absorption spectroscopy (XAS). One of three major categories of Mo(V) EPR signals from the molybdenum enzyme sulfite oxidase is the low-pH signal, which forms ...
ABSTRACT: In this article, an angle-resolved photoelectron spectroscopy (ARPES), X-ray absorption spectroscopy (XAS), and density-functional theory (DFT) investigations of water and ammonia adsorption on graphene/Ni(111) are presented. The results of adsorption on graphene/Ni(111) obtained in this study reveal the ...
In this article, an angle-resolved photoelectron spectroscopy (ARPES), X-ray absorption spectroscopy (XAS), and density-functional theory (DFT) investigations of water and ammonia adsorption on graphene/Ni(111) are presented. The results of adsorption on graphene/Ni(111) obtained in this study reveal the existence ...
The chemical and structural effects of processing on the crystallization of nitrogen doped Ge2Sb2Te5 is examined via x-ray photoelectron spectroscopy (XPS), x-ray absorption spectroscopy (XAS), time resolved laser reflectivity, and time resolved x-ray diffraction (XRD). Time resolved laser reflectivity and XRD show ...
The x-ray absorption spectroscopy (XAS) had been an essential tool to gather spectroscopic information about atomic energy level structure in the early decades of this century. It has also played an important role in the discovery and systematization of rare-earth elements. The discovery of synchrotron radiation in 1952, and later the ...
In biological systems, X-ray absorption spectroscopy (XAS) can determine structural details of metal binding sites with high resolution. Here a method enabling an automated analysis of the corresponding EXAFS data is presented, utilizing in addition to least-squares refinement the prior knowledge about structural details and important ...
Sulfur K-edge X-ray absorption spectroscopy (XAS) of anhydrous CuSO(4) reveals a well-resolved preedge transition feature at 2478.8 eV that has no counterpart in the XAS spectra of anhydrous ZnSO(4) or copper sulfate pentahydrate. Similar but weaker preedge features occur in the sulfur K-edge ...
A variety of analytical techniques augmented by the use of synchrotron radiation (SR), such as X-ray fluorescence (SR-XRF) and X-ray diffraction (SR-XRD), are now readily available, and they differ little, conceptually, from their common laboratory counterparts. Because of numerous advantages afforded by SR-based techniques over benchtop versions, however, SR methods have become popular with ...
Fungi can be highly efficient biogeochemical agents and accumulators of soluble and particulate forms of metals. This work aims to understand some of the physico-chemical mechanisms involved in toxic metal transformations focusing on the speciation of metals accumulated by fungi and mycorrhizal associations. The amorphous state or poor crystallinity of metal complexes within biomass and relatively ...
Young plants of Stackhousia tryonii Bailey were exposed to 34 mM Ni kg-1 in the form of NiSO4- 6H2O solution and grown under controlled glasshouse conditions for a period of 20 days. Fresh leaf, stem and root samples were analysed in vivo by micro x-ray absorption spectroscopy (XAS) at the Ni-K edge.Both x-ray ...
Solid transchelation reaction was established for the synthesis of bis(N-oxopyridine-2-thionato) zinc (II), commonly known as zinc pyrithione (ZPT), to control particle size using zinc basic salt (ZBS) and aqueous sodium pyrithione solution. Distinguished from ZPT particles prepared by usual precipitation reaction, the obtained ZPT nanoparticles exhibited very narrow size distribution. X-ray ...
The Versatile Spectroscopy beamline at Diamond Light Source, I20, is currently under construction and aims to begin operation in late 2009 and early 2010. The beamline aims to cover applications from physics, chemistry and biology through materials, environmental and geological science. Three very distinctive modes of operation will be offered at the beamline: scanning X-ray ...
We present an X-ray absorption spectroscopy (XAS) study of a low Pt content catalyst layer (Pt loading 0.1 mg cm(-2)) operating at the cathode of a proton exchange membrane fuel cell (PEMFC). This catalyst is based on the use of a mesoporous inorganic matrix as a support for the catalyst Pt nanoparticles. Due to the high Pt dilution, ...
approach by X-ray Absorption Spectroscopy: II. Hematite formation from ferric gels J. M. COMBES,* A through X-ray Ab- sorption Spectroscopy (XAS) during the formation of hematite from ferric gels at 92�C, hydrous gels possess a goethite/akaganeite-Iike local structure. During gel - hematite transformation
Polymer-electrolyte membrane (PEM) fuel cells are still far from an area-wide market launch due in part to long-term stability, reliability and cost issues. A more detailed knowledge of the underlying reaction mechanisms is expected to further their application, as it would allow for the design of tailor-made catalysts. However, this will only be possible by complementing traditional in situ ...
X-ray absorption spectroscopy (XAS) is ideal for {ital in}{ital situ} studies of battery materials because both the probe and signal are penetrating x rays. The advantage of XAS being element specific permits investigation of the environment of a constituent element in a composite material. This makes it very ...
We have measured the X-ray absorption (XAS) and X-ray magnetic circular dichroism (XMCD) at the Mn L{sub 3,2} edges in ferromagnetic Ga{sub 1-x}Mn{sub x}P films for 0.018 {le} x {le} 0.042. Large XMCD asymmetries at the L{sub 3} edge indicate significant spin-polarization of the density of states at the Fermi energy. The spectral shapes of the ...
Energy-Dispersive X-ray Absorption Spectroscopy (ED-XAS) data combined with UV/Vis, Raman, and mass spectrometry data on alumina- and silica-supported molybdenum oxide catalysts under propane dehydrogenation conditions have been previously reported. A novel ?? adsorbate isolation technique was applied here to the time-resolved (0.1 ...
Brominated powdered activated carbon sorbents have been shown to be quite effective for mercury capture when injected into the flue gas duct at coal-fired power plants and are especially useful when burning Western low-chlorine subbituminous coals. X-ray absorption spectroscopy (XAS) and X-ray photoelectron ...
Studies have shown that biomaterials have the capacity to adsorb heavy metals and metal oxo-cations from aqueous solution. In addition, previous studies have shown that biomaterials have the ability to bind uranyl cations from solution with capacities that are comparable to or greater than some commercially available synthetic ion-exchange resins. By using chemical modification, inductively ...
The insertion of lithium in anatase TiO{sub 2} nanoparticles under ultrahigh vacuum (UHV) conditions is studied using x-ray absorption spectroscopy (XAS) and resonant photoelectron spectroscopy (RPES) at the Ti L{sub 2,3} edge. It is demonstrated that XAS can be used to monitor the separation ...
We report an x-ray photoemission spectroscopy (XPS) and x-ray absorption spectroscopy (XAS) study on K2V8-xTixO16 (x = 0.0, 0.3, and 4.0) in which the metal-insulator transition (MIT) and the tetragonal-to-monoclinic structural transition show different responses against the Ti doping. The spectral change of V 2p ...
Electronic structures of perovskite oxides of SrMn1-xMoxO3 (0 <=x<= 0.75) have been investigated by employing soft x-ray absorption spectroscopy (XAS) and photoemission spectroscopy (PES). It is found that the valence states of Mn ions change systematically from Mn4+ for x = 0, to nearly Mn3+ for x = 0.3, and ...
The electronic structure of the insulator lithium amide (LiNH2), which is a lightweight complex hydride being considered as a high-capacity hydrogen storage material, is investigated by N 1s soft x-ray emission spectroscopy (XES) and absorption spectroscopy (XAS). The XES and XAS spectra show a ...
Hole-doped perovskites such as La{sub 1-x}Ca{sub x}MnO{sub 3} present special magnetic and magnetotransport properties, and it is commonly accepted that the local atomic structure around Mn ions plays a crucial role in determining these peculiar features. Therefore experimental techniques directly probing the local atomic structure, like x-ray absorption ...
X-ray Absorption Spectroscopy (XAS) of the Rare Earth (RE) 3d levels yields sharp peaks near the edges as a result of strong, quasi-atomic 3d{sup 10}4f {yields} 3d{sup 9}4f{sup n+1} (M{sub 4,5}) transitions that contain a wealth of spectroscopic features. XAS is a useful technique for the characterization of ...
The spin crossover phenomena has been identified in the [Fe(H2B(pz)2) bpy] where pz=(1-pyrazolyl)borate [Fe(H2B(pz)2) bpy], and but there is currently a lack of knowledge of the physical nature of this phenomena and the electronic structure of this organometallic compound has not been well characterized. We have investigated the interface electronic characteristics of molecular thin films of the ...
We report on the rapid implantation-induced amorphization of the ternary InxGa1-xAs alloys. Unlike AlxGa1-xAs , InxGa1-xAs did not exhibit amorphization kinetics intermediate between the two binary-alloy extremes. Instead, our investigation of the crystalline-to-amorphous phase transformation over the entire stoichiometry (x) range ...
In this study, oriented Photosystem II (PS II) particles from spinach chloroplasts are studied with electron paramagnetic resonance (EPR) and x-ray absorption spectroscopy (XAS) to determine more details of the structure of the oxygen evolving complex (OEC). The nature of halide binding to Mn is also studied with Cl K-edge and Mn EXAFS ...
We analyze the actinide 4f core X-ray photoemission spectra for actinide dioxide series, ThO2, UO2-BkO2, using the impurity Anderson model. Systematic variations of physical parameters, such as the charge transfer energy and the covalency hybridization strength, are investigated with the change of the actinide elements. We also calculate uranium 5d core X-ray absorption ...
Nine AuPd nanoparticle samples selectively capped with tetraoctylphosphonium bromide, primary amine and tertiary amine molecules were studied with the Au L3-edge x-ray absorption spectroscopy (XAS). The AuPd mixing patterns were analyzed by comparing the XAS results with the theoretical coordination numbers of 24 ...
We present work done on EuO films with thicknesses varying from 10 to 60 A? grown as a stepped wedge on Si/SiO2/Cr(20 A?)/Cu(90 A?) and capped with Y(20 A?)/Al(80 A?). The films were characterized by x-ray absorption spectroscopy (XAS) and x-ray magnetic circular dichroism (XMCD) at the europium M5 and copper L3 edges. The films' high ...
Electronic structural changes in LiTi(2)O(4) spinel compounds upon electrochemical lithium insertions were investigated by X-ray absorption spectroscopy (XAS) measurements and first principles calculations based on spin-polarized density functional theory. Ti K-edge, O K-edge XAS spectra and theoretical ...
X-ray absorption spectroscopy (XAS) has been used to investigate the structure and valence of thorium (Th{sup 4+}) and uranyl (UO{sub 2}{sup 2+}) cations exchanged into two classes of microporous aluminosilicate minerals: zeolites and smectite clays. XAS is also employed to examine the fate of the exchanged cations ...
One method for the in situ remediation of uranium contaminated subsurface environments is the removal of highly soluble U(VI) from groundwater by microbial reduction to the sparingly soluble U(IV) mineral uraninite. Success of this remediation strategy will, in part, be determined by the extent and products of microbial reduction. In heterogeneous subsurface environments, microbial processes will ...
We present work done on EuO films with thicknesses varying from 10 to 60 A grown as a stepped wedge on Si/Cr(20 {angstrom})/Cu(90 {angstrom}) and capped with Y(20 {angstrom})/Al(80 {angstrom}). The films were characterized by x-ray absorption spectroscopy (XAS) and x-ray magnetic circular dichroism (XMCD) at the europium M{sub 5} and ...
The speciation of Fe and Mn in road dust particles, collected on the walls and floor of the ventilation shaft of Traforo del San Bernardo highway tunnel, was studied by means of XAS spectroscopy. Absorption spectra were recorded on BM8 at the ESRF (Grenoble, France) at the Fe and Mn K-edges. Several reference compounds were measured ...
X-ray absorption spectroscopy (XAS) and high-resolution X-ray diffraction are combined to study the interplay between electronic and lattice structures in controlling the superconductivity in cuprates with a model charge-compensated CaxLa1- xBa1.75-xLa0.25+xCu3Oy (0<=x<0.5, y?7.13) system. In spite of a large change in T c, the ...
The local environment of Zr in a borosilicate glass has been investigated by combining molecular dynamics (MD) simulations with Zr K-edge x-ray absorption spectroscopy (XAS) measurements. Two- and three-body distribution functions in agreement with the experimental data were obtained. The oxygen first neighbors around Zr are found to ...
Energy Dispersive X-ray Absorption Spectroscopy is a now a well-established method which has been applied to a broad range of applications. Ten years from the construction of beamline ID24 at the ESRF, the first dispersive XAS spectrometer using undulator radiation on a third generation source, we report an overview of recent results ...
X-ray absorption spectroscopy (XAS) and magnetic circular dichroism (MCD) at the V L2,3 and C and N K edges reveal bonding/backbonding interactions in films of the 400 K magnetic semiconductor V[TCNE]x~;;2. In V spectra, dxy-like orbitals are modeled assuming V2+ in an octahedral ligand field, while dz2 and dx2-y2 orbitals involved in ...
High energy resolution and broadband efficiency are enabling the use of cryogenic detectors in biological research. Two areas where they have found initial application are X-ray absorption spectroscopy (XAS) and time-of-flight mass spectrometry (TOF-MS). In synchrotron-based fluorescence-detected XAS cryogenic ...
Characterization of pigments on decorated pottery fragments has been fully carried out by nondestructive x-ray absorbance spectroscopy (XAS). The samples were a series of pottery shards excavated from the archeological site of Caltagirone (Sicily, Italy), a well-known ceramic production center. Aesthetical criteria and morphological observations allowed us ...
... OF SOLIDS), GALLIUM COMPOUNDS, INDIUM COMPOUNDS, ARSENIDES, ABSORPTION SPECTRA, SEEBECK EFFECT, SOLID SOLUTIONS ...
In this study, we perform steady-state and time-resolved X-ray absorption spectroscopy (XAS) on the iron K-edge of [Fe(tren(py)3)](PF6)2 dissolved in acetonitrile solution. Static XAS measurements on the low-spin parent compound and its high-spin analogue, [Fe(tren(6-Me-py)3)](PF6)2, reveal distinct spectroscopic ...
X-ray absorption spectroscopy (XAS) and x-ray photoemission spectroscopy of the V L edge and O K edge were performed on VO2 thin films rf sputtered at various conditions. The spectra give evidence of the changes in the electronic structure depending on the film quality. XAS of the O K ...
X-ray absorption spectroscopy (XAS) and x-ray photoemission spectroscopy of the V L edge and O K edge were performed on VO{sub 2} thin films rf sputtered at various conditions. The spectra give evidence of the changes in the electronic structure depending on the film quality. XAS of the O K ...
A joint experimental and theoretical work to explain the electronic and geometrical structure of an in situ prepared film of iron phthalocyanine (FePc) on silicon (100) is presented. FePc molecular films have been characterized by core and valence photoemission spectroscopy (PES) and x-ray absorption spectroscopy ...
Photoelectron Spectroscopy (PES) and X-ray Absorption Spectroscopy (XAS, Figure 1) have contributed greatly to our improved understanding of Pu electronic structure. From these and related measurements, the following has been determined: (1) The Pu 5f spin-orbit splitting is large; (2) The number of Pu5f electrons ...
Mining activities in the US Western Phosphate Resource Area (WPRA) have released Se into the environment. Selenium has several different oxidation states and species, each having varying degrees of solubility, reactivity, and bioavailability. In this study we are investigating the speciation of Se in mine-waste rocks. Selenium speciation was determined using bulk and micro-x-ray ...
X-ray absorption (XAS) and emission (XES) spectroscopy near O K edge has been performed on edge-shared CuO chain compounds Ca2+xY2-xCu5O10 (0.0=x=2.0) using poly- and single-crystalline samples. Two large peaks are observed at 528 eV (PH) and 530 eV (PU) in the XAS spectra. The intensity of the PH peak ...
Catalysis investigations are often followed in a range of spectroscopic techniques. While diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) can be done on a bench-top instrument, X-ray absorption spectroscopy (XAS) techniques, such as extended X-ray absorption fine structure ...
Plant hyperaccumulation of the essential nutrient manganese (Mn) is a rare phenomenon most evident in the Western Pacific region, and differs from hyperaccumulation of other elements. Mn hyperaccumulators employ a variety of species-dependent spatial distribution patterns in sequestering excess foliar Mn, including primary sequestration in both nonphotosynthetic and photosynthetic tissues. This ...
A complete understanding of actinide interactions in the geosphere is paramount for developing a rational Nuclear and Environmental Materials Management Policy. One of the key challenges towards understanding the fate and transport of actinides is determining their speciation (i.e., oxidation state and structure). Since an element's speciation directly dictates physical properties such as ...
Chromium (Cr) is a well-established carcinogen that is a contaminant at half of the EPA Superfund sites in the United States. Two separate studies were performed to investigate the possibility that mesquite (Prosopis spp.), which is an indigenous desert plant species, can remove Cr from the environment via active transport systems to the aerial portions of the plant. The first study was performed ...
The adsorption mechanisms of monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA) on nanocrystalline titanium oxide (TiO2) were investigated with X-ray absorption spectroscopy (XAS), surface charge and zeta potential measurements, adsorption edge, and surface complexation modeling. XAS data demonstrated that ...
In this study, Mn has been doped (0-33%) into 6 nm, ?-Fe2O3 nanoparticles grown inside the horse-spleen ferritin (HSF) protein and compared to similarly protein encapsulated pure ?-Fe2O3 and Mn-oxide nanoparticles to determine the Mn doping site. By using soft-X-ray absorption spectroscopy (XAS), soft-X-ray magnetic circular dichroism ...
Lithium-ion batteries with high energy and power density are needed for a variety of new technologies. The materials that are used in the cathodes and anodes of these batteries have crystal structures that can accommodate and release lithium over a fairly large composition range. Over 95% of commercial lithium-ion batteries use LiCoO2 cathodes, but the high cost of cobalt makes cheaper ...
The remarkable polarization properties of synchrotron light have lead to the advent of modern synchrotron-related spectroscopic studies with angular and/or magnetic selectivity. Here an overview is given of the prominent aspects of the polarization of the light delivered by a bending magnet, and some dichroic properties in X-ray absorption spectroscopy ...
We have employed element and chemically sensitive X-ray absorption spectroscopy (XAS) and X-ray magnetic circular dichroism (XMCD) in order to address a long standing controversy regarding the electronic and magnetic state of CuCr{sub 2}Se{sub 4} via halogen doping of the Se anion site in CuCr{sub 2}Se{sub 4-x}Y{sub x} (Y=Cl and Br). ...
We element specifically studied the electronic and magnetic states of epitaxially grown full-Heusler alloy Co2MnSi (CMS) 1.1 nm (4 ML) thick ultrathin films facing an epitaxial MgO(001) tunnel barrier by means of x-ray absorption spectroscopy (XAS) and x-ray magnetic circular dichroism (XMCD). In situ reflection high-energy ...
The photoexcited states of metal complexes are precursors for many important photochemical processes in solution phase. Using laser-initiated time-resolved x-ray absorption spectroscopy (LITR-XAS), transient metal oxidation states, coordination geometry, and atomic rearrangements that closely reflect photochemical processes can be ...
Systematic Mn K-edge x-ray absorption spectroscopy (XAS) measurements on samples of La{sub 1{minus}x}Sr{sub x}MnO{sub 3}, which are precursors to colossal magnetoresistive (CMR) materials, are reported. Detailed results on the edge or chemical shift as a function of Sr concentration (hole doping) and sample preparation (air vs oxygen ...
This paper reports an x-ray absorption spectroscopy (XAS) analysis of the local structure around lead contained in foam glasses prepared with waste funnel cathode-ray tube glasses (CRT) and three reducing agents AlN, TiN and SiC. The XAS data were collected at the Pb-L(III) edge to measure the influence of the ...
This paper reports an x-ray absorption spectroscopy (XAS) analysis of the local structure around lead contained in foam glasses prepared with waste funnel cathode-ray tube glasses (CRT) and three reducing agents AlN, TiN and SiC. The XAS data were collected at the Pb-LIII edge to measure the influence of the ...
In chemical vapor deposited (CVD) organosilicate glasses (OSG), which are used as interlayer dielectric (ILD) materials, the substitution of oxygen in SiO2 by methyl groups (-CH3) reduces the permittivity significantly. However, plasma processing for resist stripping, trench etching and post-etch cleaning removes C and H containing molecular groups from the near-surface layer of OSG. Therefore, ...
We investigated the electronic structures of a poly sodium 4-styrensulfonate intercalated graphite oxide (PSSGO) electrode and a precursor graphite oxide (GO) electrode using X-ray absorption spectroscopy (XAS). Both electrodes were obtained from electrochemical cells. We found that in the C K-edge XAS spectra the ...
The new core XAS spectroscopy beamline at Diamond (B18) has been designed to provide a reliable spectrometer for a broad scientific community. The instrument first became operational in April 2010 and is currently combining further commissining with a rapidly growing user programme. The main goal of the optics design of B18 was to achieve high stability in ...
Present and future nuclear fuel cycles will require an understanding of the complex chemistry of trace fission products and transuranium actinides in spent nuclear fuel (SNF). Because of the unique analytical challenges presented by SNF to the materials scientist, many of its fundamental physical and chemical properties remain poorly understood, especially on the microscopic scale. Such an ...
P K-edge X-ray absorption spectroscopy (XAS) has been carried out to investigate the electronic structure of the electrochemically delithiated Li{sub 1-x}FePO{sub 4} for Li rechargeable batteries. The gradual shift of main edge features to higher energy side showed that P-O bonds become less covalent during delithiation due to the more ...
In the present work, cobalt-doped magnetites, prepared by the co-precipitation method, were mainly studied by X-ray absorption and M�ssbauer spectroscopies. From the chemical analysis, it was observed that the continuous increase of Co2+ is followed by a simultaneous decrease of the Fe2+ contents, in the spinel structure. Room temperature M�ssbauer ...
A sample cell and low-temperature cooling unit design suitable for x-ray absorption spectroscopy (XAS) of oxygen and/or water sensitive compounds is presented. The cell is a simplified and optimized modification of a previously suggested design. The low-temperature accessory is specifically designed for good thermal isolation and ...
We present the first x-ray absorption spectroscopy (XAS) data at the Fe K-edge collected on insoluble mineral dust from Talos Dome firn core (TDC, 159�04'E, 72�46'S, 2316 m a.s.l., mean accumulation rate 8 g cm-2 yr- 1), drilled in the framework of the International Trans Antarctic Scientific Expedition (ITASE), and from a Colle ...
Sorption of dissolved strontium on kaolinite, amorphous silica, and goethite was studied as a function of pH, aqueous strontium concentration, the presence or absence of atmospheric CO{sub 2} or dissolved phosphate, and aging over a 57-day period. Selected sorption samples ([Sr(a1)]{sub i} {approximately} 0.5--1 x 10{sup {minus}3}m) were examined with synchrotron X-ray ...
X-ray absorption spectroscopy (XAS) and photoemission electron microscopy (PEEM) are techniques commonly used to determine the magnetic properties of thin films, crystals, and heterostructures. Recently, these methods have been used in the study of magnetoelectrics, possessing both ferroelectric and magnetic order; however, the ...
Soft X-ray absorption spectroscopy (XAS), using fluorescence yield, was used to study the boron K near edge in MgB2 superconductor. The sample consists of MgB2 crystallites randomly oriented in a magnesium matrix. Abrasion of the sample surface in vacuum provides a surface relatively free of boron-containing impurities. The intrinsic ...
High-throughput experimentation has been applied to X-ray Absorption spectroscopy as a novel route for increasing research productivity in the catalysis community. Suitable instrumentation has been developed for the rapid determination of the local structure in the metal component of precursors for supported catalysts. An automated analytical workflow was ...
We have studied the electronic properties of YBa/sub 2/Cu/sub 3/O/sub 7/ and EuBa/sub 2/Cu/sub 3/O/sub 7/ superconductors with soft x-ray absorption spectroscopy (XAS) at BESSY. Electronic transitions to unoccupied states (holes) of 2p and 3d character on O and Cu, respectively, are found in superconducting specimens. In samples with ...
The electronic structures of HgII, NiII, CrIII, and MoV complexes with cysteine were investigated by sulfur K-edge X-ray absorption near-edge structure (XANES) spectroscopy and density functional theory. The covalency in the metal-sulfur bond was determined by analyzing the intensities of the electric-dipole allowed pre-edge features appearing in the XANES ...
The electronic structures of Hg{sup II}, Ni{sup II}, Cr{sup III}, and Mo{sup V} complexes with cysteine were investigated by sulfur K-edge X-ray absorption near-edge structure (XANES) spectroscopy and density functional theory. The covalency in the metal-sulfur bond was determined by analyzing the intensities of the electric-dipole allowed pre-edge ...
The unique features of X-ray absorption spectroscopy allow investigations of nanosized catalysts for fuel cells under working conditions. We present the results of an experiment carried out on a low Pt content electrocatalyst supported by a mesoporous heteropolyacid salt and used at the cathode of a proton exchange membrane fuel cell (PEMFC). The analysis ...
