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X-ray reflectivity, diffraction and grazing incidence small angle X-ray scattering as complementary methods in the microstructural study of sol–gel zirconia thin films

X-ray reflectivity, diffraction and grazing incidence small angle X-ray scattering as complementary methods in the microstructural study of sol–gel zirconia thin films

Keywords: Sol – gel coating; Zirconium oxide; X-ray scattering; Nanostructure 1. Introduction The elaboration of inorganic thin layers presents a growing interest because a new thermal, mechanical, optical, chemical or electrical property is easily added to the substrates on which they are deposited [1] . Among all the methods of thin film synthesis, chemical or physical vapour deposition, pulverization, molecular beam epitaxy or laser ablation, the interest of sol – gel route is unquestionable mainly because of its low cost, its easiness to control the synthesis parameters and the high precision in mixing different precursors for the fabrication of multicomponents oxides layers. Moreover, the sol gel route suits quite well to very large or complex form substrates [2] .
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TiC-carbide derived carbon electrolyte adsorption study by ways of X-ray scattering analysis

TiC-carbide derived carbon electrolyte adsorption study by ways of X-ray scattering analysis

X-ray scattering is a powerful technique for investigat- ing both atomic ordering and electronic density contrast evolution linked with pore filling. Usually, the range of distances to be analysed is so different that, for technical reasons, two different experimental set up must be used: small angle X-ray scattering (SAXS) and wide angle X-ray scattering (WAXS). SAXS brings information about phe- nomena impacting large distance range such as pore filling, while WAXS is used to study short (interatomic) distances. However, the high capacitance observed in porous carbons being associated with the presence of micropores with size close to interatomic distances (between 0.6 and 1 nm), these sizes are small enough to generate ‘‘typical SAXS’’ patterns in the lowest part of the angular range normally used to investigate interatomic distances. That makes the use of the WAXS technique sufficient to investigate both pore filling and pore wall modifications. Moreover, the access to low and high angles parts in a single experiment allows an easy evaluation of the ratio between the different components (carbon, electrolyte, sample holder) useful to separate their contributions.
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Unraveling Direct Formation of Hierarchical Zeolite Beta by Dynamic Light Scattering, Small Angle X-ray Scattering, and Liquid and Solid-State NMR: Insights at the Supramolecular Level

Unraveling Direct Formation of Hierarchical Zeolite Beta by Dynamic Light Scattering, Small Angle X-ray Scattering, and Liquid and Solid-State NMR: Insights at the Supramolecular Level

toolbox applicable to clear solutions and dense gels, combined with a characterization of the resulting zeolite materials disclosed a series of self-assembly processes that govern the growth (and growth inhibition) of nano-Beta zeolite crystals, which assemble in micron-sized aggregates. In clear solution, small angle X-ray scattering and liquid state NMR provide insights about the formation of nanoparticles and their degree of order. 14 N and 1 H-DOSY NMR probe the dynamics and mobility of soluble species . In a dense gel, on the other side, 27 Al- and 29 Si-(MAS)-NMR elucidate the varying local connectivity between initial nano-objects and the final solid products. It has been found that, cylindrical micelles control the transformation of solubilized silica and alumina during the formation of zeolite nuclei and guide their crystal growth to nano-Beta rods with bimodal mesoporosity. The predominant smaller mesopores originate from the template's hydrophobic alkyl chains, while larger mesopores (10 to 30 nm) are supposed to result from a spinodal decomposition-type segregation of phases consisting of as-formed hydrophobic zeolite rods and an aqueous solution.
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Mapping the unoccupied state dispersions in ${\mathrm{Ta}}_{2}{\mathrm{NiSe}}_{5}$ with resonant inelastic x-ray scattering

Mapping the unoccupied state dispersions in ${\mathrm{Ta}}_{2}{\mathrm{NiSe}}_{5}$ with resonant inelastic x-ray scattering

involving a small lattice distortion. Below T c , a band gap at the center of its Brillouin zone increases up to about 0.35 eV. In this work, we study the electronic structure of Ta 2 NiSe 5 in its low-temperature semiconducting phase, using resonant inelastic x-ray scattering (RIXS) at the Ni L 3 edge. In addition to a weak fluorescence response, we observe a collection of intense Raman-like peaks that we attribute to electron-hole excitations. Using density functional theory calculations of its electronic band structure, we identify the main Raman-like peaks as interband transitions between valence and conduction bands. By performing angle-dependent RIXS measurements, we uncover the dispersion of these electron-hole excitations that allows us to extract the low-energy boundary of the electron-hole continuum. From the dispersion of the valence band measured by angle-resolved photoemission spectroscopy, we derive the effective mass of the lowest unoccupied conduction band.
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Low-temperature structure of magnetite studied using resonant x-ray scattering

Low-temperature structure of magnetite studied using resonant x-ray scattering

II. RESONANT X-RAY SCATTERING AS A TOOL TO SOLVE A STRUCTURE The atomic scattering factors become complex at energies around the absorption edge of the resonant atom in a given material. 22 As a consequence, diffraction near the edges vio- lates Friedel’s law 关I共Q ជ 兲⫽I共−Q ជ 兲兴 and can be used, for in- stance, to identify enantiomorphs. Moreover it permits to highlight a specific atom from the rest of the atoms in a given structure, which is especially useful when the crystal- lized molecule contains a large number of atoms. 23 It is also useful to stress the contrast between elements of close atomic number. The multiple-wavelength anomalous diffraction 共MAD兲 is a technique where complete sets of diffraction peaks are collected at a number of photon energies around the resonant共s兲 atom and simultaneously refined. This method is extensively used in the crystallography of biologi- cal materials, and especially of proteins. Our technique, RXS, is different. We record the energy dependence of the intensity of many diffracted peaks in a relatively small en- ergy range around the edge where the atomic scattering am- plitude is highly sensitive to the electric and geometrical local environment of the absorbing atoms. In the specialized literature this technique is also called diffraction anomalous near edge structure 共DANES兲.
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X-Ray Absorption Spectroscopy and Anomalous Wide Angle X-Ray Scattering: Two Basic Tools in the Analysis of Heterogeneous Catalysts

X-Ray Absorption Spectroscopy and Anomalous Wide Angle X-Ray Scattering: Two Basic Tools in the Analysis of Heterogeneous Catalysts

PSA [25], Elf [26], DSM [27], Shell [28, 29], Rhodia [30], Total [31, 32], Mobil [33], or Exxon [34]. Photon-matter interaction occurs via two fundamental channels: absorption (the energy of the photon is lost within the target) and scattering processes which can be either elastic (Thomson scattering for free electrons) or inelastic (Compton scattering). Note that the interaction of photons with nuclei is out of the X-ray range considered here (between 3 to 25 KeV). The particular properties of synchrotron radiation such as the wide spectral range and the exceptional flux have led to the development of various techniques such as X-ray absorption spectroscopy (XAS) using either soft [35] and hard X-rays as well as anomalous wide angle X-ray scattering (AWAXS) [36, 37].
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Light-induced structural changes in a full-length cyanobacterial phytochrome probed by time- resolved X-ray scattering

Light-induced structural changes in a full-length cyanobacterial phytochrome probed by time- resolved X-ray scattering

On longer timescales considerable differences start to appear in the shape of the X-ray scattering difference patterns between the photosensory region and the full-length protein. Indeed, a large X-ray scattering change is evident in the small-angle region for the full-length protein, indicating that large scale motions occur and most likely involve the transmission of the structural signal to the output domain. Interestingly, both the X-ray scattering and optical spectroscopy kinetics are slightly faster in the full-length protein than in the photosensory domain. This may be due to differences in the solvent environment which may affect the internal protein dynamics and/or to a more efficient dissipation mechanism in the full-length protein where the light perturbation is transferred from the photosensory domain to the output domain. The final structural changes in both forms of the protein occur on slower timescales than is observed spectroscopically, as illustrated by the fact that the structural rearrangement is still evolving after the longest X-ray scattering time-delay of 500 ms. Hence, it is likely that these slower conformational changes in the protein do not impact on the environment of the chromophore as it is not reflected in any noticeable absorbance change. This finding is in contrast to previous studies on the full-length bac- terial phytochrome where the main structural changes were completed prior to the final observed spectroscopic evolution 8 .
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Scattering density profile model of POPG bilayers as determined by molecular dynamics simulations and small-angle neutron and x-ray scattering experiments

Scattering density profile model of POPG bilayers as determined by molecular dynamics simulations and small-angle neutron and x-ray scattering experiments

’ MATERIALS AND METHODS Synthetic 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylgly- cerol (C16:0-18:1PG, POPG) was purchased from Avanti Polar Lipids (Alabaster, AL) and used without further purification. Fifty milligrams of POPG was mixed with 1 mL of 100 mM NaCl solution made using D 2 O (99.9% pure, Chalk River Labo- ratories), while 7.5 mg of POPG was mixed with 0.4 mL of nondeuterated 100 mM NaCl solution (18 MΩcm H 2 O). Lipid mixtures were temperature cycled through the main phase transition until uniform dispersions of multilamellar vesicles (MLVs) were obtained. Unilamellar vesicles (ULVs) were then prepared from these dispersions at temperatures above POPG’s main phase transition temperature ( 2 C) 20 using an Avanti mini- extruder fitted with two 0.25 mL airtight syringes. MLVs were extruded through two polycarbonate filters populated with 500 Å diameter pores, producing ULVs with diameters of ∼600 Å. 21 Finally, samples were diluted with D 2 O or H 2 O (100 mM NaCl solutions) to the desired external contrast condition (i.e., 100%, 70% and 50% D 2 O in the case of neutron contrast variation experiments, and 100% H 2 O in the case of X-ray scattering experiments). The total lipid concentration of all ULV samples was ∼20 mg/mL, guaranteeing the presence of sufficient amounts of water between ULVs, thus eliminating the possibility of interparticle interactions (i.e., structure factor). 21
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Small-Angle x-ray scattering and crystallographic studies of arcelin-1: An insecticidal lectin-like glycoprotein fromPhaseolus vulgaris L

Small-Angle x-ray scattering and crystallographic studies of arcelin-1: An insecticidal lectin-like glycoprotein fromPhaseolus vulgaris L

19. Depautex, C., Desvignes, C., Leboucher, P., Lemonnier, M., Dagneaux, D., Benoit, J.P., Vachette, P. LURE Annual report 1985–1987, Doc. CEN Saclay, 1987. 20. Bordas, J., Koch, M.H.J., Clout, P.N., Dorrington, E., Boulin, C., Gabriel, A. A synchrotron radiation camera and data acquisition system for time resolved x-ray scattering studies. J. Phys., E: Sci. Instrum. 13:938–944, 1980. 21. Dubuisson, J.M., Decamps, T., Vachette, P. Improved signal-

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Chemical composition of nano-phases studied by anomalous small-angle X-ray scattering (ASAXS)

Chemical composition of nano-phases studied by anomalous small-angle X-ray scattering (ASAXS)

MAUGIS, Sébastien JEGOU, Laurent BARRALLIER - Chemical composition of nano-phases studied by anomalous small-angle X-ray scattering (ASAXS) - 2014.. Any correspondence concerning this se[r]

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Improving sensitivity of a small angle x-ray scattering camera with pinhole collimation using separated optical elements

Improving sensitivity of a small angle x-ray scattering camera with pinhole collimation using separated optical elements

We show that a significant improvement in the sensitivity of a Huxley–Holmes design for a small angle x-ray scattering camera is obtained by separating the mirror and the monochromator. The design of the camera involves a long x-ray mirror close to a point x-ray source associated with a curved focusing crystal located close to the sample. The sample area is located at half the distance between the source and detector planes. Diffuse scattering produced by the mirror is not incident on the focusing crystal, thus reducing the background signal. Complete elimination of hard x rays allows precise calibration and hence absolute determination of sample cross section by means of a semitransparent beam stop. In pinhole geometry, the flux corresponds to a ⬃10 7 photons/s through the sample, collimated to 10 ⫺2 Å ⫺1 in q range. This allows determination of scattered intensities on the order of 10 ⫺3 cm ⫺1 , corresponding to the scattering related to isothermal compressibility of less than 0.1 mm of pure water. As a reference sample, the widely used Lupolen™, a semicrystalline polymer, is calibrated. The high-q limit (q ⬇4.5 nm ⫺1 ) of a porous calcite sample can be used as a secondary standard for specific area determination of solid/solid or solid–liquid dispersions. © 2003 American Institute of Physics. 关DOI: 10.1063/1.1556954兴
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New reactor dedicated to in operando studies of model catalysts by means of surface x-ray diffraction and grazing incidence small angle x-ray scattering

New reactor dedicated to in operando studies of model catalysts by means of surface x-ray diffraction and grazing incidence small angle x-ray scattering

A new experimental setup has been developed to enable in situ studies of catalyst surfaces during chemical reactions by means of surface x-ray diffraction 共SXRD兲 and grazing incidence small angle x-ray scattering. The x-ray reactor chamber was designed for both ultrahigh-vacuum 共UHV兲 and reactive gas environments. A laser beam heating of the sample was implemented; the sample temperature reaches 1100 K in UHV and 600 K in the presence of reactive gases. The reactor equipment allows dynamical observations of the surface with various, perfectly mixed gases at controlled partial pressures. It can run in two modes: as a bath reactor in the pressure range of 1 – 1000 mbars and as a continuous flow cell for pressure lower than 10 −3 mbar. The reactor is connected to an UHV preparation chamber also equipped with low energy electron diffraction and Auger spectroscopy. This setup is thus perfectly well suited to extend in situ studies to more complex surfaces, such as epitaxial films or supported nanoparticles. It offers the possibility to follow the chemically induced changes of the morphology, the structure, the composition, and growth processes of the model catalyst surface during exposure to reactive gases. As an example the Pd 8 Ni 92 共110兲 surface structure was followed by SXRD under a few millibars of hydrogen and during butadiene hydrogenation while the reaction was monitored by quadrupole mass spectrometry. This experiment evidenced the great sensitivity of the diffracted intensity to the subtle interaction between the surface atoms and the gas molecules. © 2007 American Institute of Physics.
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Applications of Neutron and X-ray Scattering to the Study of Biologically Relevant Model Membranes

Applications of Neutron and X-ray Scattering to the Study of Biologically Relevant Model Membranes

Pabst et al. (2007a) , and inset shows the crystallographic structure of alamethicin ( Fox and Richards, 1982 ). Alamethicin is a 20 amino acid fungal peptide from Trichoderma viride and is known to form pores in membranes ( Bezrukov and Vodyanoy, 1997 ). This pore formation ability is promoted by its amphiphatic ␣-helical structure, where the peptide’s hydropho- bic side faces the membrane’s interior and its hydrophilic side forms the aqueous surface of the pore. At very low peptide-to-lipid molar ratios, alamethicin, like many other amphiphatic peptides, adsorbs to the membrane with its helical axis parallel to the mem- brane surface, leading to a local deformation ( He et al., 1996; Heller et al., 1997 ). As the peptide concentration is increased, the pep- tides accumulate on the membrane surface – possibly aggregating – and above a certain threshold concentration insert transver- sally into the membrane forming a pore ( Huang, 2006 ). Using the OS technique in combination with X-ray scattering, it was shown by Pabst et al. (2007a) ( Fig. 13 ) and later on by Pan et al. (2009) that the pore formation process “softens” DOPC bilay- ers by ∼50%. This result is consistent with the other studies that recorded a drop in membrane bending rigidity in the presence of amphiphatic peptides ( Vitkova et al., 2006; Tristram-Nagle and Nagle, 2007 ).
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Neutron and X-ray Scattering for Biophysics and Biotechnology: Examples of Self-Assembled Lipid Systems

Neutron and X-ray Scattering for Biophysics and Biotechnology: Examples of Self-Assembled Lipid Systems

First published as an Advance Article on the web 27th May 2009 DOI: 10.1039/b819799g Membranes that surround cells and separate their contents from the external environment are ubiquitous in biological systems. These membranes are organized assemblies consisting mainly of lipids and proteins, and are highly selective permeability barriers which control the flow of information between cells and their environment. It is accepted that the lipid bilayer is the underlying structure of most, if not all, biomembranes. As such, over the years scientists have exerted much effort in studying lipid bilayers and their biological relevance in hopes of understanding the functional mechanisms taking place at membrane interfaces. Neutron and X-ray scattering techniques are powerful tools for the characterization of the structure and dynamics of biomimetic systems as they provide unique access to microscopic structure and dynamics at length scales ranging from microns to intermolecular and/or atomic distances. The optimization of instruments and preparation techniques, as well as the new possibilities offered by protein deuteration, have opened up new avenues for the study of lipid/protein interactions that were not previously possible. One can now look at the insertion of biomolecules into membranes and accurately determine the structure as well as the dynamics of the interaction. To illustrate the usefulness of diffraction and scattering techniques with regard to biologically relevant systems, we review some of the leading edge studies that have taken place over the last couple of years in which these scattering techniques have played a central role.
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Coupling high throughput microfluidics and small-angle x-ray scattering to study protein crystallization from solution

Coupling high throughput microfluidics and small-angle x-ray scattering to study protein crystallization from solution

DOI: 10.1021/acs.analchem.6b03492 ABSTRACT: In this work, we propose the combination of small-angle X-ray scattering (SAXS) and high throughput, droplet based micro fluidics as a powerful tool to investigate macromolecular interactions, directly related to protein solubility. For this purpose, a robust and low cost micro fluidic platform was fabricated for achieving the mixing of proteins, crystallization reagents, and bu ffer in nanoliter volumes and the subsequent generation of nanodroplets by means of a two phase flow. The protein samples are compartmentalized inside droplets, each one acting as an isolated microreactor. Hence their physicochemical conditions (concentration, pH, etc.) can be finely tuned without cross-contamination, allowing the screening of a huge number of saturation conditions with a small amount of biological material. The droplet flow is synchronized with synchrotron radiation SAXS measurements to probe protein interactions while minimizing radiation damage. To this end, the experimental setup was tested with rasburicase (known to be very sensitive to denaturation), proving the structural stability of the protein in the droplets and the absence of radiation damage. Subsequently weak interaction variations as a function of protein saturation was studied for the
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Comparison of resonant inelastic x-ray scattering spectra and dielectric loss functions in copper oxides

Comparison of resonant inelastic x-ray scattering spectra and dielectric loss functions in copper oxides

T. Gog and D. Casa XOR, Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA 共Received 27 December 2008; revised manuscript received 4 February 2009; published 30 March 2009 兲 We report empirical comparisons of Cu K-edge indirect resonant inelastic x-ray scattering 共RIXS兲 spectra, taken at the Brillouin-zone center, with optical dielectric loss functions measured in a number of copper oxides. The RIXS data are obtained for Bi 2 CuO 4 , CuGeO 3 , Sr 2 Cu 3 O 4 Cl 2 , La 2 CuO 4 , and Sr 2 CuO 2 Cl 2 , and analyzed by considering both incident and scattered-photon resonances. An incident-energy-independent response function is then extracted. The dielectric loss functions, measured with spectroscopic ellipsometry, agree well with this RIXS response, especially in Bi 2 CuO 4 and CuGeO 3 .
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Small-angle X-ray scattering and small-angle neutron scattering studies of liquid-crystalline halato(semi)telechelic polymers

Small-angle X-ray scattering and small-angle neutron scattering studies of liquid-crystalline halato(semi)telechelic polymers

systematic observation of a greater dIP in the Pis (7.57 and 8.48 nm) relative to the PSs (6 44 and 6.83 nm). These experimental observations suggest that, all other conditions being constant, polyisoprene chains yield a greater dIP than the corresponding polystyrene, whatever the functionality of the chain. In all cases, dIP is greater than the observed value for the PIS2Xs. Combining all the previous results shows that the greater distance between the ionic aggregates in the present study results from the replacement of the metallic cations, as previously investigated, by the mesogenic cation. The layer spacing of the mesogenic cation can be valued at about 3.2 nm, in agreement with the data published by Ujiie & Iimura (1992) on the same pure mesogenic ion analysed by wide-angle X-ray scattering.
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Characterization of a Fe/Y[subscript 2]O[subscript 3] metal/oxide interface using neutron and x-ray scattering

Characterization of a Fe/Y[subscript 2]O[subscript 3] metal/oxide interface using neutron and x-ray scattering

monochromator. Analysis of specular NR data provides information on the coherent nuclear scattering length density (n-SLD) and the magnetic component of the scattering length density (m-SLD) 11 as a function of depth normal to the sample sur- face. The n-SLD depth profile is uniquely determined by the composition and density of the sample and m-SLD by the magnetic properties of the film. Because the SPEAR neutron beam is not polarized, reflectivities for spin-up and spin-down polarizations in magnetic films are added inco- herently to simulate the measured reflectivity curve. This procedure assumes that magnetic domains are larger than the coherency of the neutron beam ( !lm). XR provides in- formation on the x-ray scattering length densities (x-SLD), which are generally complex to account for x-ray absorption.
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Metrology of Nanoparticles with Small Angles X-Ray Scattering (SAXS) : from simple cases to nanoparticles in food additives

Metrology of Nanoparticles with Small Angles X-Ray Scattering (SAXS) : from simple cases to nanoparticles in food additives

Metrology of Nanoparticles with Small Angles X-Ray Scattering (SAXS) : from simple cases to nanoparticles in food additives O. Taché, Dr. V. Geersten, E . Barruet, Dr. O. Spalla , Dr. A. Thill, Dr F. Testard, S. Doco NIMBE (Nanoscience & Innovation Laboratory) / Fundamental Research Division / CEA Paris-Saclay

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Microstructure Characterization of a Nitrided Fe- 3wt.%Cr-0.3wt.%C Model Alloy by Anomalous Small Angle X-ray Scattering

Microstructure Characterization of a Nitrided Fe- 3wt.%Cr-0.3wt.%C Model Alloy by Anomalous Small Angle X-ray Scattering

Experimental method Small-angle X-ray scattering is a powerful technique for investigation of nanometric particles and provide statistical data. Moreover SAXS carried out in the anomalous mode at the Cr-edge can provide information on the Cr-composition of the nano-nitrides [3]. Experiments were carried out on the BM02-D2AM, a French CRG beamline at the European Synchrotron Radiation Facilities (ESRF) in Grenoble. Two samples were studied with the same composition (0.35 wt.% C, 1.0wt% Cr, Fe balance) and two different nitriding conditions (10 or 100 h at 550 °C).
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