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Sample records for in-situ energy-dispersive x-ray

  1. Soil characterization by energy dispersive X-ray fluorescence: sampling strategy for in situ analysis.

    PubMed

    Custo, Graciela; Boeykens, Susana; Dawidowski, L; Fox, L; Gómez, D; Luna, F; Vázquez, Cristina

    2005-07-01

    This work describes a sampling strategy that will allow the use of portable EDXRF (energy dispersive X-ray fluorescence) instruments for "in situ" soil analysis. The methodology covers a general approach to planning field investigations for any type of environmental studies and it was applied for a soil characterization study in the zone of Campana, Argentina, by evaluating data coming from an EDXRF spectrometer with a radioisotope excitation source. Simulating non-treated sampled as "in situ" samples and a soil characterization for Campana area was intended. "In situ" EDXRF methodology is a powerful analytical modality with the advantage of providing data immediately, allowing a fast general screening of the soil composition. PMID:16038489

  2. In situ energy dispersive x-ray reflectometry measurements on organic solar cells upon working

    NASA Astrophysics Data System (ADS)

    Paci, B.; Generosi, A.; Albertini, V. Rossi; Perfetti, P.; de Bettignies, R.; Firon, M.; Leroy, J.; Sentein, C.

    2005-11-01

    The change in the morphology of plastic solar cells was studied by means of time-resolved energy dispersive x-ray reflectivity (XRR). This unconventional application of the XRR technique allowed the follow up of in situ morphological evolution of an organic photovoltaic device upon working. The study consisted of three steps: A preliminary set of XRR measurements on various samples representing the intermediate stages of cell construction, which provided accurate data regarding the electronic densities of the different layers; the verification of the morphological stability of the device under ambient condition; a real-time collection of XRR patterns, both in the dark and during 15h in artificial light conditions which allowed the changes in the system morphology at the electrode-active layer interface to be monitored. In this way, a progressive thickening of this interface, responsible for a reduction in the performances of the device, was observed directly.

  3. In situ energy-dispersive x-ray diffraction system for time-resolved thin-film growth studies

    NASA Astrophysics Data System (ADS)

    Ellmer, K.; Mientus, R.; Weiß, V.; Rossner, H.

    2003-03-01

    Energy-dispersive x-ray diffraction (EDXRD) with synchrotron light can be used for in situ-structural analysis during polycrystalline thin-film growth, due to its fast data collection and the fixed diffraction angle. An in situ deposition and analysis set-up for the investigation of nucleation and growth of thin films during magnetron sputtering was constructed and installed at the synchrotron radiation source Hamburger Synchrotronstrahlungs Labor (Hamburg). The polychromatic synchrotron beam passes the sputtering chamber through Kapton windows and hits the substrate with the growing film. The diffracted beam, observed under a fixed diffraction angle of between 1° and 10° was energy-analysed by a high-purity germanium detector. The measurement time for a single XRD spectrum can be as short as 10 s for a beam line at a bending magnet, which allows a time-resolved monitoring of film growth. The performance of the in situ EDXRD set-up is demonstrated for the growth of zinc oxide and tin-doped indium oxide films prepared by reactive magnetron sputtering from ceramic and metallic targets. From the position and the width of the diffraction lines the internal mechanical strain and the grain size of the growing films can be derived. The prospects for thin-film growth investigations using such an instrument are assessed.

  4. In situ multi-element analyses by energy-dispersive X-ray fluorescence on varnishes of historical violins

    NASA Astrophysics Data System (ADS)

    Echard, Jean-Philippe

    2004-10-01

    Varnishes of Italian violins and other historical stringed instruments have been analyzed by energy-dispersive X-ray fluorescence (EDXRF). The instruments whose varnishes were to be analyzed were chosen from the collection kept in Musée de la Musique in Paris. Direct analyses were performed on instrument varnishes, without any sampling and non-destructively, showing inorganic elements such as lead, mercury and iron that could be related to siccatives or pigments. Analytical results and their comparison with old formulae or traditional recipes of violin varnishes, as with the few previous analytical results, will be discussed.

  5. In-situ and operando characterization of batteries with energy-dispersive synchrotron x-ray diffraction

    NASA Astrophysics Data System (ADS)

    Paxton, William Arthur

    Batteries play a pivotal role in the low-carbon society that is required to thwart the effects of climate change. Alternative low-carbon energy sources, such as wind and solar, are often intermittent and unreliable. Batteries are able capture their energy and deliver it later when it is needed. The implementation of battery systems in grid-level and transportation sectors is essential for efficient use of alternative energy sources. Scientists and engineers need better tools to analyze and measure the performance characteristics of batteries. One of the main hindrances in the progress of battery research is that the constituent electrode materials are inaccessible once an electrochemical cell is constructed. This leaves the researcher with a limited number of available feedback mechanisms to assess the cell's performance, e.g., current, voltage, and impedance. These data are limited in their ability to reveal the more-localized smaller-scale structural mechanisms on which the batteries' performance is so dependent. Energy-dispersive x-ray diffraction (EDXRD) is one of the few techniques that can internally probe a sealed battery. By analyzing the structural behavior of battery electrodes, one is able to gain insight to the physical properties on which the battery's performance is dependent. In this dissertation, EDXRD with ultrahigh energy synchrotron radiation is used to probe the electrodes of manufactured primary and secondary lithium batteries under in-situ and operando conditions. The technique is then applied to solve specific challenges facing lithium ion batteries. Diffraction spectra are collected from within a battery at 40 micrometer resolution. Peak-fitting is used to quantitatively estimate the abundance of lithiated and non-lithiated phases. Through mapping the distribution of phases within, structural changes are linked to the battery's galvanic response. A three-dimensional spatial analysis of lithium iron phosphate batteries suggests that evolution

  6. In situ measurement of the deuterium (hydrogen) charging of a palladium electrode during electrolysis by energy dispersive x-ray diffraction

    NASA Astrophysics Data System (ADS)

    Felici, R.; Bertalot, L.; DeNinno, A.; LaBarbera, A.; Violante, V.

    1995-05-01

    A method to determine the concentration of deuterium inside a palladium cathode during the electrolysis of LiOD-heavy water solution is described. This method is based on the measurement of the host metal lattice parameter which is linearly related to the concentration in a wide range. A hard-x-ray beam which is able to cross two glass walls and few centimeters of water solutions without suffering a strong attenuation has been used. The measurement of the lattice parameter is performed in situ, during the electrolysis, by using energy dispersive x-ray diffraction. The sample volume illuminated by the x-ray beam is limited to a small region close to the surface and depends on the incident photon energy. In principle, this allows one to study the dynamics of the charging process and to determine the concentration profile in the range from few up to tens of micrometers. The deuterium concentration, determined by this method, was then checked by degassing the cathode in a known volume and was always found in a very good agreement, showing that the charging was uniform for the whole sample.

  7. Spatially resolved energy dispersive x-ray spectroscopic method for in-situ evaluation of mechanical properties during the growth of a C - Pt composite nanowire

    NASA Astrophysics Data System (ADS)

    Banerjee, Amit; Banerjee, S. S.

    2014-05-01

    A core-shell type C-Pt composite nanowire is fabricated using focused ion and electron beam induced chemical vapor deposition techniques. Using information from spatially resolved energy dispersive x-ray spectra, we detect the resonance vibration in the C-Pt composite nanowire. We use this method to measure the Young's moduli of the constituents (C, Pt) of the composite nanowire and also estimate the density of the FEB CVD grown Pt shell surrounding the C core. By measuring the resonance characteristics of the composite nanowire we estimate a Pt shell growth rate of ˜0.9 nms-1. The study is analyzed to suggest that the Pt shell growth mechanism is primarily governed by the sticking coefficient of the organometallic vapor on the C nanowire core.

  8. Spatially resolved energy dispersive x-ray spectroscopic method for in-situ evaluation of mechanical properties during the growth of a C - Pt composite nanowire

    SciTech Connect

    Banerjee, Amit; Banerjee, S. S.

    2014-05-15

    A core-shell type C-Pt composite nanowire is fabricated using focused ion and electron beam induced chemical vapor deposition techniques. Using information from spatially resolved energy dispersive x-ray spectra, we detect the resonance vibration in the C-Pt composite nanowire. We use this method to measure the Young's moduli of the constituents (C, Pt) of the composite nanowire and also estimate the density of the FEB CVD grown Pt shell surrounding the C core. By measuring the resonance characteristics of the composite nanowire we estimate a Pt shell growth rate of ∼0.9 nms{sup −1}. The study is analyzed to suggest that the Pt shell growth mechanism is primarily governed by the sticking coefficient of the organometallic vapor on the C nanowire core.

  9. In situ strain profiling of elastoplastic bending in Ti-6Al-4V alloy by synchrotron energy dispersive x-ray diffraction

    SciTech Connect

    Croft, M.; Shukla, V.; Akdogan, E. K.; Sadangi, R.; Ignatov, A.; Balarinni, L.; Tsakalakos, T.; Jisrawi, N.; Zhong, Z.; Horvath, K.

    2009-05-01

    Elastic and plastic strain evolution under four-point bending has been studied by synchrotron energy dispersive x-ray diffraction. Measured strain profiles across the specimen thickness showed an increasing linear elastic strain gradient under increasing four-point bending load up to approx2 kN. The bulk elastic modulus of Ti-6Al-4V was determined as 118 GPa. The onset of plastic deformation was found to set in at a total in-plane strain of approx0.008, both under tension and compression. Plastic deformation under bending is initiated in the vicinity of the surface and at a stress of 1100 MPa, and propagates inward, while a finite core region remains elastically deformed up to 3.67 kN loading. The onset of the plastic regime and the plastic regime itself has been verified by monitoring the line broadening of the (100) peak of alpha-Ti. The effective compression/tension stress-strain curve has been obtained from the scaling collapse of strain profile data taken at seven external load levels. A similar multiple load scaling collapse of the plastic strain variation has also been obtained. The level of precision in strain measurement reported herein was evaluated and found to be 1.5x10{sup -5} or better.

  10. Portable energy dispersive X-ray fluorescence and X-ray diffraction and radiography system for archaeometry

    NASA Astrophysics Data System (ADS)

    Mendoza Cuevas, Ariadna; Perez Gravie, Homero

    2011-03-01

    Starting on a laboratory developed portable X-ray fluorescence (PXRF) spectrometer; three different analytical results can be performed: analysis of chemical elements, analysis of major chemical crystalline phase and structural analysis, which represents a contribution to a new, low cost development of portable X-ray analyzer; since these results are respectively obtained with independent equipments for X-ray fluorescence, X-ray diffraction and radiography. Detection limits of PXRF were characterized using standard reference materials for ceramics, glass, bronze and bones, which are the main materials requiring quantitative analysis in art and archeological objects. A setup for simultaneous energy dispersive X-ray fluorescence and diffraction (ED (XRF-XRD)) in the reflection mode has been tested for in situ and non-destructive analysis according to the requirements of art objects inspection. The system uses a single low power X-ray tube and an X-ray energy dispersive detector to measure X-ray diffraction spectrum at a fixed angle. Application to the identification of jadeite-jade mineral in archeological objects by XRD is presented. A local high resolution radiography image obtained with the same low power X-ray tube allows for studies in painting and archeological bones.

  11. Single atom identification by energy dispersive x-ray spectroscopy

    SciTech Connect

    Lovejoy, T. C.; Dellby, N.; Krivanek, O. L.; Ramasse, Q. M.; Falke, M.; Kaeppel, A.; Terborg, R.; Zan, R.

    2012-04-09

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

  12. Electrochemical Reduction of Ag2VP2O8 Composite Electrodes Visualized via In situ Energy Dispersive X-ray Diffraction (EDXRD). Unexpected Conductive Additive Effects

    SciTech Connect

    Kirshenbaum, Kevin C.; Bock, David C.; Zhong, Zhong; Marschilok, Amy C.; Takeuchi, Kenneth J.; Takeuchi, Esther

    2015-07-29

    In our study, we characterize the deposition of silver metal nanoparticles formed during discharge of Li/Ag2VP2O8 cells with composite cathodes containing conductive carbon additive. Using in situ energy dispersive X-ray diffraction (EDXRD) of an intact battery, the location and distribution of silver metal nanoparticles generated upon reduction-displacement deposition within an Ag2VP2O8 cathode containing a pre-existing percolation network can be observed for the first time. Our study yielded unexpected results where higher rate initial discharge generated a more effective conductive matrix. This stands in contrast to cells with cathodes with no conductive additive where a low rate initial discharge proved more effective. Our results provide evidence that using conductive additives in conjunction with an in situ reduction-displacement deposition of silver metal provides a path toward the ultimate goal of complete electrical contact and full utilization of all electroactive particles.

  13. Anomalous lattice expansion in yttria stabilized zirconia under simultaneous applied electric and thermal fields: A time-resolved in situ energy dispersive x-ray diffractometry study with an ultrahigh energy synchrotron probe

    SciTech Connect

    Akdogan, E. K.; Savkl Latin-Small-Letter-Dotless-I y Latin-Small-Letter-Dotless-I ld Latin-Small-Letter-Dotless-I z, I.; Bicer, H.; Paxton, W.; Toksoy, F.; Tsakalakos, T.; Zhong, Z.

    2013-06-21

    Nonisothermal densification in 8% yttria doped zirconia (8YSZ) particulate matter of 250 nm median particle size was studied under 215 V/cm dc electric field and 9 Degree-Sign C/min heating rate, using time-resolved in-situ high temperature energy dispersive x-ray diffractometry with a polychromatic 200 keV synchrotron probe. Densification occurred in the 876-905 Degree-Sign C range, which resulted in 97% of the theoretical density. No local melting at particle-particle contacts was observed in scanning electron micrographs, implying densification was due to solid state mass transport processes. The maximum current draw at 905 Degree-Sign C was 3 A, corresponding to instantaneous absorbed power density of 570 W/cm{sup 3}. Densification of 8YSZ was accompanied by anomalous elastic volume expansions of the unit cell by 0.45% and 2.80% at 847 Degree-Sign C and 905 Degree-Sign C, respectively. The anomalous expansion at 905 Degree-Sign C at which maximum densification was observed is characterized by three stages: (I) linear stage, (II) anomalous stage, and (III) anelastic recovery stage. The densification in stage I (184 s) and II (15 s) was completed in 199 s, while anelastic relaxation in stage III lasted 130 s. The residual strains ({epsilon}) at room temperature, as computed from tetragonal (112) and (211) reflections, are {epsilon}{sub (112)} = 0.05% and {epsilon}{sub (211)} = 0.13%, respectively. Time dependence of (211) and (112) peak widths ({beta}) show a decrease with both exhibiting a singularity at 905 Degree-Sign C. An anisotropy in (112) and (211) peak widths of {l_brace} {beta}{sub (112)}/{beta}{sub (211)}{r_brace} = (3:1) magnitude was observed. No phase transformation occurred at 905 Degree-Sign C as verified from diffraction spectra on both sides of the singularity, i.e., the unit cell symmetry remains tetragonal. We attribute the reduction in densification temperature and time to ultrafast ambipolar diffusion of species arising from the

  14. Measuring Performance of Energy-Dispersive X-ray Systems.

    PubMed

    Statham

    1998-11-01

    : As Si(Li) detector technology has matured, many of the fundamental problems have been addressed in the competition among manufacturers and there is now an expectation, implied by many textbooks, that all energy-dispersive X-ray (EDX) detectors are made and will perform in the same way. Although there has been some convergence in Si(Li) systems and these are still the most common, manufacturing recipes still differ and there are many alternative EDX devices, such as microcalorimeters and room temperature detectors, that have both advantages and disadvantages over Si(Li). Rather than emphasizing differences in technologies, performance measures should reveal benefits relevant to the intended application. The instrument is inevitably going to be a "black box" of integrated components; this article reviews some of the methods that have been applied and introduces some new techniques that can be used to assess performance without resorting to complex software or sophisticated mathematical algorithms. Sensitivity, resolution, artefacts, and stability are discussed with particular application to compositional analysis using electron beam excitation of X-rays in the 100-eV to 10-keV energy region. PMID:10087283

  15. Energy Dispersive X-Ray and Electrochemical Impedance Spectroscopies for Performance and Corrosion Analysis of PEMWEs

    NASA Astrophysics Data System (ADS)

    Steen, S. M., Iii; Zhang, F.-Y.

    2014-11-01

    Proton exchange membrane water electrolyzers (PEMWEs) are a promising energy storage technology due to their high efficiency, compact design, and ability to be used in a renewable energy system. Before they are able to make a large commercial impact, there are several hurdles facing the technology today. Two powerful techniques for both in-situ and ex- situ characterizations to improve upon their performance and better understand their corrosion are electrochemical impedance spectroscopy and energy dispersive x-ray spectroscopy, respectively. In this paper, the authors use both methods in order to characterize the anode gas diffusion layer (GDL) in a PEMWE cell and better understand the corrosion that occurs in the oxygen electrode during electrolysis.

  16. Focal construct geometry for high intensity energy dispersive x-ray diffraction based on x-ray capillary optics.

    PubMed

    Li, Fangzuo; Liu, Zhiguo; Sun, Tianxi; Jiang, Bowen; Zhu, Yu

    2016-03-14

    We presented a focal construct geometry (FCG) method for high intensity energy dispersive X-ray diffraction by utilizing a home-made ellipsoidal single-bounce capillary (ESBC) and a polycapillary parallel X-ray lens (PPXRL). The ESBC was employed to focus the X-rays from a conventional laboratory source into a small focal spot and to produce an annular X-ray beam in the far-field. Additionally, diffracted polychromatic X-rays were confocally collected by the PPXRL attached to a stationary energy-resolved detector. Our FCG method based on ESBC and PPXRL had achieved relatively high intensity diffraction peaks and effectively narrowed the diffraction peak width which was helpful in improving the potential d-spacing resolution for material phase analysis. PMID:26979685

  17. Focal construct geometry for high intensity energy dispersive x-ray diffraction based on x-ray capillary optics

    NASA Astrophysics Data System (ADS)

    Li, Fangzuo; Liu, Zhiguo; Sun, Tianxi; Jiang, Bowen; Zhu, Yu

    2016-03-01

    We presented a focal construct geometry (FCG) method for high intensity energy dispersive X-ray diffraction by utilizing a home-made ellipsoidal single-bounce capillary (ESBC) and a polycapillary parallel X-ray lens (PPXRL). The ESBC was employed to focus the X-rays from a conventional laboratory source into a small focal spot and to produce an annular X-ray beam in the far-field. Additionally, diffracted polychromatic X-rays were confocally collected by the PPXRL attached to a stationary energy-resolved detector. Our FCG method based on ESBC and PPXRL had achieved relatively high intensity diffraction peaks and effectively narrowed the diffraction peak width which was helpful in improving the potential d-spacing resolution for material phase analysis.

  18. Micro energy dispersive X-ray fluorescence analysis of polychrome lead-glazed Portuguese faiences

    NASA Astrophysics Data System (ADS)

    Guilherme, A.; Pessanha, S.; Carvalho, M. L.; dos Santos, J. M. F.; Coroado, J.

    2010-04-01

    Several glazed ceramic pieces, originally produced in Coimbra (Portugal), were submitted to elemental analysis, having as premise the pigment manufacture production recognition. Although having been produced in Coimbra, their location changed as time passed due to historical reasons. A recent exhibition in Coimbra brought together a great number of these pieces and in situ micro Energy Dispersive X-ray Fluorescence (µ-EDXRF) analyses were performed in order to achieve some chemical and physical data on the manufacture of faiences in Coimbra. A non-commercial µ-EDXRF equipment for in situ analysis was employed in this work, carrying some important improvements when compared to the conventional ones, namely, analyzing spot sizes of about 100 µm diameter. The combination of a capillary X-ray lens with a new generation of low power microfocus X-ray tube and a drift chamber detector enabled a portable unit for micro-XRF with a few tens of µm lateral resolution. The advantages in using a portable system emphasized with polycapillary optics enabled to distinguish proximal different pigmented areas, as well as the glaze itself. These first scientific results on the pigment analysis of the collection of faiences seem to point to a unique production center with own techniques and raw materials. This conclusion arose with identification of the blue pigments having in its constitution Mn, Fe Co and As and the yellows as a result of the combination between Pb and Sb. A statistical treatment was used to reveal groups of similarities on the pigments elemental profile.

  19. Single photon energy dispersive x-ray diffraction

    SciTech Connect

    Higginbotham, Andrew; Patel, Shamim; Ciricosta, Orlando; Suggit, Matthew J.; Wark, Justin S.; Hawreliak, James A.; Collins, Gilbert W.; Coppari, Federica; Eggert, Jon H.; Tang, Henry

    2014-03-15

    With the pressure range accessible to laser driven compression experiments on solid material rising rapidly, new challenges in the diagnosis of samples in harsh laser environments are emerging. When driving to TPa pressures (conditions highly relevant to planetary interiors), traditional x-ray diffraction techniques are plagued by increased sources of background and noise, as well as a potential reduction in signal. In this paper we present a new diffraction diagnostic designed to record x-ray diffraction in low signal-to-noise environments. By utilising single photon counting techniques we demonstrate the ability to record diffraction patterns on nanosecond timescales, and subsequently separate, photon-by-photon, signal from background. In doing this, we mitigate many of the issues surrounding the use of high intensity lasers to drive samples to extremes of pressure, allowing for structural information to be obtained in a regime which is currently largely unexplored.

  20. Energy Dispersive Spectrometry and Quantitative Analysis Short Course. Introduction to X-ray Energy Dispersive Spectrometry and Quantitative Analysis

    NASA Technical Reports Server (NTRS)

    Carpenter, Paul; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    This course will cover practical applications of the energy-dispersive spectrometer (EDS) to x-ray microanalysis. Topics covered will include detector technology, advances in pulse processing, resolution and performance monitoring, detector modeling, peak deconvolution and fitting, qualitative and quantitative analysis, compositional mapping, and standards. An emphasis will be placed on use of the EDS for quantitative analysis, with discussion of typical problems encountered in the analysis of a wide range of materials and sample geometries.

  1. Analysis of tincal ore waste by energy dispersive X-ray fluorescence (EDXRF) Technique

    NASA Astrophysics Data System (ADS)

    Kalfa, Orhan Murat; Üstündağ, Zafer; Özkırım, Ilknur; Kagan Kadıoğlu, Yusuf

    2007-01-01

    Etibank Borax Plant is located in Kırka-Eskişehir, Turkey. The borax waste from this plant was analyzed by means of energy dispersive X-ray fluorescence (EDXRF). The standard addition method was used for the determination of the concentration of Al, Fe, Zn, Sn, and Ba. The results are presented and discussed in this paper.

  2. Energy-Dispersive X-Ray Fluorescence Spectrometry: A Long Overdue Addition to the Chemistry Curriculum

    ERIC Educational Resources Information Center

    Palmer, Peter T.

    2011-01-01

    Portable Energy-Dispersive X-Ray Fluorescence (XRF) analyzers have undergone significant improvements over the past decade. Salient advantages of XRF for elemental analysis include minimal sample preparation, multielement analysis capabilities, detection limits in the low parts per million (ppm) range, and analysis times on the order of 1 min.…

  3. Energy Dispersive X-ray Tomography for 3D Elemental Mapping of Individual Nanoparticles.

    PubMed

    Slater, Thomas J A; Lewis, Edward A; Haigh, Sarah J

    2016-01-01

    Energy dispersive X-ray spectroscopy within the scanning transmission electron microscope (STEM) provides accurate elemental analysis with high spatial resolution, and is even capable of providing atomically resolved elemental maps. In this technique, a highly focused electron beam is incident upon a thin sample and the energy of emitted X-rays is measured in order to determine the atomic species of material within the beam path. This elementally sensitive spectroscopy technique can be extended to three dimensional tomographic imaging by acquiring multiple spectrum images with the sample tilted along an axis perpendicular to the electron beam direction. Elemental distributions within single nanoparticles are often important for determining their optical, catalytic and magnetic properties. Techniques such as X-ray tomography and slice and view energy dispersive X-ray mapping in the scanning electron microscope provide elementally sensitive three dimensional imaging but are typically limited to spatial resolutions of > 20 nm. Atom probe tomography provides near atomic resolution but preparing nanoparticle samples for atom probe analysis is often challenging. Thus, elementally sensitive techniques applied within the scanning transmission electron microscope are uniquely placed to study elemental distributions within nanoparticles of dimensions 10-100 nm. Here, energy dispersive X-ray (EDX) spectroscopy within the STEM is applied to investigate the distribution of elements in single AgAu nanoparticles. The surface segregation of both Ag and Au, at different nanoparticle compositions, has been observed. PMID:27403838

  4. X-ray photo-emission and energy dispersive spectroscopy of HA coated titanium

    SciTech Connect

    Drummond, J.L.; Steinberg, A.D.; Krauss, A.R.

    1997-08-01

    The purpose of this study was to determine the chemical composition changes of hydroxyapatite (HA) coated titanium using surface analysis (x-ray photo-emission) and bulk analysis (energy dispersive spectroscopy). The specimens examined were controls, 30 minutes and 3 hours aged specimens in distilled water or 0.2M sodium phosphate buffer (pH 7.2) at room temperature. Each x-ray photo-emission cycle consisted of 3 scans followed by argon sputtering for 10 minutes for a total of usually 20 cycles, corresponding to a sampling depth of {approximately} 1500 {angstrom}. The energy dispersive spectroscopy analysis was on a 110 by 90 {mu}m area for 500 sec. Scanning electron microscopy examination showed crystal formation (3P{sub 2}O{sub 5}*2CAO*?H{sub 2}O by energy dispersive spectroscopy analysis) on the HA coating for the specimens aged in sodium phosphate buffer. The x-ray photo-emission results indicated the oxidation effect of water on the titanium (as TiO{sub 2}) and the effect of the buffer to increase the surface concentration of phosphorous. No differences in the chemical composition were observed by energy dispersive spectroscopy analysis. The crystal growth was only observed for the sodium phosphate buffer specimens and only on the HA surface.

  5. The 20 element HgI2 energy dispersive x ray array detector system

    NASA Astrophysics Data System (ADS)

    Iwanczyk, J. A.; Dorri, N.; Wang, M.; Szczebiot, R. W.; Dabrowski, A. J.; Hedman, B.; Hodgson, K. O.; Patt, B. E.

    1991-11-01

    This paper describes recent progress in the development of HgI2 energy dispersive x-ray detector arrays and associated miniaturized processing electronics for synchrotron radiation research applications. The experimental results with a 20 element array detector were obtained under realistic synchrotron beam conditions at SSRL. An energy resolution of 250 eV (FWHM) at 5.9 keV (Mn-K(sub a)) was achieved. Energy resolution and throughput measurements versus input count rate and energy of incoming radiation have been measured. Extended X-ray Absorption Fine Structure (EXAFS) spectra were taken from diluted samples simulating proteins with nickel.

  6. Scanning electron microscope/energy dispersive x ray analysis of impact residues in LDEF tray clamps

    NASA Technical Reports Server (NTRS)

    Bernhard, Ronald P.; Durin, Christian; Zolensky, Michael E.

    1993-01-01

    Detailed optical scanning of tray clamps is being conducted in the Facility for the Optical Inspection of Large Surfaces at JSC to locate and document impacts as small as 40 microns in diameter. Residues from selected impacts are then being characterized by Scanning Electron Microscopy/Energy Dispersive X-ray Analysis at CNES. Results from this analysis will be the initial step to classifying projectile residues into specific sources.

  7. Superconducting Detector System for High-Resolution Energy-Dispersive Soft X-Ray Spectroscopy

    SciTech Connect

    Friedrich, S; Niedermayr, T; Drury, O; Funk, T; Frank, M; Labov, S E; Cramer, S

    2001-02-21

    Synchrotron-based soft x-ray spectroscopy is often limited by detector performance. Grating spectrometers have the resolution, but lack the efficiency for the analysis of dilute samples. Semiconducting Si(Li) or Ge detectors are efficient, but often lack the resolution to separate weak signals from strong nearby lines in multi-element samples. Superconducting tunnel junctions (STJs) operated at temperatures below 1 K can be used as high-resolution high-efficiency x-ray detectors. They combine high energy resolution around 10 eV FWHM with the broad band efficiency of energy-dispersive detectors. We have designed a two-stage adiabatic demagnetization refrigerator (ADR) to operate STJ detectors in x-ray fluorescence measurements at beam line 4 of the ALS. We demonstrate the capabilities of such a detector system for fluorescence analysis of dilute metal sites in proteins and inorganic model compounds.

  8. New software to model energy dispersive X-ray diffraction in polycrystalline materials

    NASA Astrophysics Data System (ADS)

    Ghammraoui, B.; Tabary, J.; Pouget, S.; Paulus, C.; Moulin, V.; Verger, L.; Duvauchelle, Ph.

    2012-02-01

    Detection of illicit materials, such as explosives or drugs, within mixed samples is a major issue, both for general security and as part of forensic analyses. In this paper, we describe a new code simulating energy dispersive X-ray diffraction patterns in polycrystalline materials. This program, SinFullscat, models diffraction of any object in any diffractometer system taking all physical phenomena, including amorphous background, into account. Many system parameters can be tuned: geometry, collimators (slit and cylindrical), sample properties, X-ray source and detector energy resolution. Good agreement between simulations and experimental data was obtained. Simulations using explosive materials indicated that parameters such as the diffraction angle or the energy resolution of the detector have a significant impact on the diffraction signature of the material inspected. This software will be a convenient tool to test many diffractometer configurations, providing information on the one that best restores the spectral diffraction signature of the materials of interest.

  9. Determination of carrier yields for neutron activation analysis using energy dispersive X-ray spectrometry

    USGS Publications Warehouse

    Johnson, R.G.; Wandless, G.A.

    1984-01-01

    A new method is described for determining carrier yield in the radiochemical neutron activation analysis of rare-earth elements in silicate rocks by group separation. The method involves the determination of the rare-earth elements present in the carrier by means of energy-dispersive X-ray fluorescence analysis, eliminating the need to re-irradiate samples in a nuclear reactor after the gamma ray analysis is complete. Results from the analysis of USGS standards AGV-1 and BCR-1 compare favorably with those obtained using the conventional method. ?? 1984 Akade??miai Kiado??.

  10. Distinction between entrance and exit wounds by energy dispersive X-ray fluorescence spectrometry.

    PubMed

    Tanaka, Naoko; Kinoshita, Hiroshi; Takakura, Ayaka; Jamal, Mostofa; Ito, Asuka; Kumihashi, Mitsuru; Tsutsui, Kunihiko; Kimura, Shoji; Ameno, Kiyoshi

    2016-09-01

    We investigated gunshot wounds in two autopsy cases using energy dispersive X-ray spectrometry (EDX). Lead and copper were detected in the entrance wound of one case and lead, antimony, and copper were detected in that of the other case. In the exit wounds of both cases, lead, antimony, and copper were below detection limits. These findings indicate that the detection of metallic elements, such as lead, antimony, and copper, which are found in bullets, may be useful for differentiating entrance from exit wounds using EDX. PMID:27591531

  11. The SLcam: a full-field energy dispersive X-ray camera

    NASA Astrophysics Data System (ADS)

    Bjeoumikhov, A.; Buzanich, G.; Langhoff, N.; Ordavo, I.; Radtke, M.; Reinholz, U.; Riesemeier, H.; Scharf, O.; Soltau, H.; Wedell, R.

    2012-11-01

    The color X-ray camera (SLcam®) is a full-field single photon imager. As stand-alone camera, it is applicable for energy and space-resolved X-ray detection measurements. The exchangeable poly-capillary optics in front of a beryllium entrance window conducts X-ray photons from the probe to distinguished energy dispersive pixels on a pnCCD. The dedicated software enables the acquisition and the online processing of the spectral data for all 69696 pixels, leading to a real-time visualization of the element distribution in a sample. No scanning system is employed. A first elemental composition image of the sample is visible within minutes while statistics is improving in the course of time. Straight poly-capillary optics allows for 1:1 imaging with a space resolution of 50 μm and no limited depth of sharpness, ideal to map uneven objects. Using conically shaped optics, a magnification of 6 times was achieved with a space resolution of 10 μm. We present a measurement with a laboratory source showing the camera capability to perform fast full-field X-ray Fluorescence (FF-XRF) imaging with an easy, portable and modular setup.

  12. In-situ mechanical testing during X-ray diffraction

    SciTech Connect

    Van Swygenhoven, Helena Van Petegem, Steven

    2013-04-15

    Deforming metals during recording X-ray diffraction patterns is a useful tool to get a deeper understanding of the coupling between microstructure and mechanical behaviour. With the advances in flux, detector speed and focussing techniques at synchrotron facilities, in-situ mechanical testing is now possible during powder diffraction and Laue diffraction. The basic principle is explained together with illustrative examples.

  13. Determination of selenium in biological samples with an energy-dispersive X-ray fluorescence spectrometer.

    PubMed

    Li, Xiaoli; Yu, Zhaoshui

    2016-05-01

    Selenium is both a nutrient and a toxin. Selenium-especially organic selenium-is a core component of human nutrition. Thus, it is very important to measure selenium in biological samples. The limited sensitivity of conventional XRF hampers its widespread use in biological samples. Here, we describe the use of high-energy (100kV, 600W) linearly polarized beam energy-dispersive X-Ray fluorescence spectroscopy (EDXRF) in tandem with a three-dimensional optics design to determine 0.1-5.1μgg(-1) levels of selenium in biological samples. The effects of various experimental parameters such as applied voltage, acquisition time, secondary target and various filters were thoroughly investigated. The detection limit of selenium in biological samples via high-energy (100kV, 600W) linearly polarized beam energy-dispersive X-ray fluorescence spectroscopy was decreased by one order of magnitude versus conventional XRF (Paltridge et al., 2012) and found to be 0.1μg/g. To the best of our knowledge, this is the first report to describe EDXRF measurements of Se in biological samples with important implications for the nutrition and analytical chemistry communities. PMID:26922394

  14. Practical applications of energy dispersive X-ray microanalysis in diagnostic oral pathology

    SciTech Connect

    Daley, T.D.; Gibson, D. )

    1990-03-01

    Energy dispersive X-ray microanalysis is a powerful tool that can reveal the presence and relative quantities of elements in minute particles in biologic materials. Although this technique has been used in some aspects of dental research, it has rarely been applied to diagnostic oral pathology. The purpose of this paper is to inform practicing dentists and oral specialists about the diagnostic potential of this procedure by presenting three case reports. The first case involved the identification of flakes of a metallic material claimed by a 14-year-old girl to appear periodically between her mandibular molars. In the second case, a periodontist was spared a lawsuit when a freely mobile mass in the antrum of his patient was found to be a calcium-phosphorus compound not related to the periodontal packing that had been used. The third case involved the differential diagnosis of amalgam tattoo and graphite tattoo in a pigmented lesion of the hard palate mucosa. The results of the analyses were significant and indicate a role for this technique in the assessment of selected cases. Potential for wider use of energy dispersive X-ray microanalysis in diagnostic oral pathology exists as research progresses.

  15. X-ray coherent scattering form factors of tissues, water and plastics using energy dispersion

    NASA Astrophysics Data System (ADS)

    King, B. W.; Landheer, K. A.; Johns, P. C.

    2011-07-01

    A key requirement for the development of the field of medical x-ray scatter imaging is accurate characterization of the differential scattering cross sections of tissues and phantom materials. The coherent x-ray scattering form factors of five tissues (fat, muscle, liver, kidney, and bone) obtained from butcher shops, four plastics (polyethylene, polystyrene, lexan (polycarbonate), nylon), and water have been measured using an energy-dispersive technique. The energy-dispersive technique has several improvements over traditional diffractometer measurements. Most notably, the form factor is measured on an absolute scale with no need for scaling factors. Form factors are reported in terms of the quantity x = λ-1sin (θ/2) over the range 0.363-9.25 nm-1. The coherent form factors of muscle, liver, and kidney resemble those of water, while fat has a narrower peak at lower x, and bone is more structured. The linear attenuation coefficients of the ten materials have also been measured over the range 30-110 keV and parameterized using the dual-material approach with the basis functions being the linear attenuation coefficients of polymethylmethacrylate and aluminum.

  16. Quantitative energy-dispersive x-ray diffraction for identification of counterfeit medicines: a preliminary study

    NASA Astrophysics Data System (ADS)

    Crews, Chiaki C. E.; O'Flynn, Daniel; Sidebottom, Aiden; Speller, Robert D.

    2015-06-01

    The prevalence of counterfeit and substandard medicines has been growing rapidly over the past decade, and fast, nondestructive techniques for their detection are urgently needed to counter this trend. In this study, energy-dispersive X-ray diffraction (EDXRD) combined with chemometrics was assessed for its effectiveness in quantitative analysis of compressed powder mixtures. Although EDXRD produces lower-resolution diffraction patterns than angular-dispersive X-ray diffraction (ADXRD), it is of interest for this application as it carries the advantage of allowing the analysis of tablets within their packaging, due to the higher energy X-rays used. A series of caffeine, paracetamol and microcrystalline cellulose mixtures were prepared with compositions between 0 - 100 weight% in 20 weight% steps (22 samples in total, including a centroid mixture), and were pressed into tablets. EDXRD spectra were collected in triplicate, and a principal component analysis (PCA) separated these into their correct positions in the ternary mixture design. A partial least-squares (PLS) regression model calibrated using this training set was validated using both segmented cross-validation, and with a test set of six samples (mixtures in 8:1:1 and 5⅓:2⅓:2⅓ ratios) - the latter giving a root-mean square error of prediction (RMSEP) of 1.30, 2.25 and 2.03 weight% for caffeine, paracetamol and cellulose respectively. These initial results are promising, with RMSEP values on a par with those reported in the ADXRD literature.

  17. Towards hybrid pixel detectors for energy-dispersive or soft X-ray photon science.

    PubMed

    Jungmann-Smith, J H; Bergamaschi, A; Brückner, M; Cartier, S; Dinapoli, R; Greiffenberg, D; Huthwelker, T; Maliakal, D; Mayilyan, D; Medjoubi, K; Mezza, D; Mozzanica, A; Ramilli, M; Ruder, Ch; Schädler, L; Schmitt, B; Shi, X; Tinti, G

    2016-03-01

    JUNGFRAU (adJUstiNg Gain detector FoR the Aramis User station) is a two-dimensional hybrid pixel detector for photon science applications at free-electron lasers and synchrotron light sources. The JUNGFRAU 0.4 prototype presented here is specifically geared towards low-noise performance and hence soft X-ray detection. The design, geometry and readout architecture of JUNGFRAU 0.4 correspond to those of other JUNGFRAU pixel detectors, which are charge-integrating detectors with 75 µm × 75 µm pixels. Main characteristics of JUNGFRAU 0.4 are its fixed gain and r.m.s. noise of as low as 27 e(-) electronic noise charge (<100 eV) with no active cooling. The 48 × 48 pixels JUNGFRAU 0.4 prototype can be combined with a charge-sharing suppression mask directly placed on the sensor, which keeps photons from hitting the charge-sharing regions of the pixels. The mask consists of a 150 µm tungsten sheet, in which 28 µm-diameter holes are laser-drilled. The mask is aligned with the pixels. The noise and gain characterization, and single-photon detection as low as 1.2 keV are shown. The performance of JUNGFRAU 0.4 without the mask and also in the charge-sharing suppression configuration (with the mask, with a `software mask' or a `cluster finding' algorithm) is tested, compared and evaluated, in particular with respect to the removal of the charge-sharing contribution in the spectra, the detection efficiency and the photon rate capability. Energy-dispersive and imaging experiments with fluorescence X-ray irradiation from an X-ray tube and a synchrotron light source are successfully demonstrated with an r.m.s. energy resolution of 20% (no mask) and 14% (with the mask) at 1.2 keV and of 5% at 13.3 keV. The performance evaluation of the JUNGFRAU 0.4 prototype suggests that this detection system could be the starting point for a future detector development effort for either applications in the soft X-ray energy regime or for an energy-dispersive

  18. Energy dispersive x-ray diffraction of charge density waves via chemical filtering

    SciTech Connect

    Feng Yejun; Somayazulu, M. S.; Jaramillo, R.; Rosenbaum, T.F.; Isaacs, E.D.; Hu Jingzhu; Mao Hokwang

    2005-06-15

    Pressure tuning of phase transitions is a powerful tool in condensed matter physics, permitting high-resolution studies while preserving fundamental symmetries. At the highest pressures, energy dispersive x-ray diffraction (EDXD) has been a critical method for geometrically confined diamond anvil cell experiments. We develop a chemical filter technique complementary to EDXD that permits the study of satellite peaks as weak as 10{sup -4} of the crystal Bragg diffraction. In particular, we map out the temperature dependence of the incommensurate charge density wave diffraction from single-crystal, elemental chromium. This technique provides the potential for future GPa pressure studies of many-body effects in a broad range of solid state systems.

  19. Characterization of small noble metal electrodes by voltammetry and energy dispersive x ray analysis

    NASA Astrophysics Data System (ADS)

    Strein, Timothy G.; Ewing, Andrew G.

    1993-01-01

    Construction and characterization of platinum and gold electrodes with total structural diameters of 1-2 micrometers is described. These small voltammetric probes have been constructed by direct electroreduction of noble metals onto the tips of etched carbon fiber microdisk electrodes. Voltammetry, electron microscopy, energy-dispersive x-ray analysis, and pulsed amperometric detection have been used to characterize these electrodes. Dopamine concentrations have been determined over a range of 10(exp -4) to 10(exp -3) M in the biological buffer system which contains 25 mM glucose, a compound known to adsorb strongly to electrodes. Amperometric monitoring at a constant potential with these small results in signal decay of 20% to 40% in a ten minute experiment. Pulsed amperometric detection minimizes electrode fouling, resulting in 5% or less signal decay over the same ten minute period.

  20. Evaluation on determination of iodine in coal by energy dispersive X-ray fluorescence

    USGS Publications Warehouse

    Wang, B.; Jackson, J.C.; Palmer, C.; Zheng, B.; Finkelman, R.B.

    2005-01-01

    A quick and inexpensive method of relative high iodine determination from coal samples was evaluated. Energy dispersive X-ray fluorescence (EDXRF) provided a detection limit of about 14 ppm (3 times of standard deviations of the blank sample), without any complex sample preparation. An analytical relative standard deviation of 16% was readily attainable for coal samples. Under optimum conditions, coal samples with iodine concentrations higher than 5 ppm can be determined using this EDXRF method. For the time being, due to the general iodine concentrations of coal samples lower than 5 ppm, except for some high iodine content coal, this method can not effectively been used for iodine determination. More work needed to meet the requirement of determination of iodine from coal samples for this method. Copyright ?? 2005 by The Geochemical Society of Japan.

  1. Compositional analysis of Ceramic Glaze by Laser Induced Breakdown Spectroscopy and Energy Dispersive X-Ray

    NASA Astrophysics Data System (ADS)

    Khedr, A.; Abdel-kareem, O.; Elnabi, S. H.; Harith, M. A.

    2011-09-01

    Laser induced breakdown spectroscopy (LIBS) has been applied for the analysis of Egyptian Islamic glaze ceramic sample. The sample dating back to Fatimid period (969-1169AD), and collected from Al-Fustat excavation store in Cairo. The analysis of contaminated pottery sample has been performed to draw mapping for the elemental compositions by LIBS technique. LIBS measurements have been done by the fundamental wavelength (1064 nm) of Nd: YAG laser for the elemental analysis and performing the cleaning processes of the pottery sample. In addition, complementary analyses were carried out by scanning electron microscopy linked with energy dispersive X-ray microanalysis (SEM/EDX) to obtain verification of chemical results. The morphological surfaces before and after cleaning has been done by Optical Microscopy (OM).

  2. Quantitative atomic resolution elemental mapping via absolute-scale energy dispersive X-ray spectroscopy.

    PubMed

    Chen, Z; Weyland, M; Sang, X; Xu, W; Dycus, J H; LeBeau, J M; D'Alfonso, A J; Allen, L J; Findlay, S D

    2016-09-01

    Quantitative agreement on an absolute scale is demonstrated between experiment and simulation for two-dimensional, atomic-resolution elemental mapping via energy dispersive X-ray spectroscopy. This requires all experimental parameters to be carefully characterized. The agreement is good, but some discrepancies remain. The most likely contributing factors are identified and discussed. Previous predictions that increasing the probe forming aperture helps to suppress the channelling enhancement in the average signal are confirmed experimentally. It is emphasized that simple column-by-column analysis requires a choice of sample thickness that compromises between being thick enough to yield a good signal-to-noise ratio while being thin enough that the overwhelming majority of the EDX signal derives from the column on which the probe is placed, despite strong electron scattering effects. PMID:27258645

  3. Setup for in situ X-ray diffraction studies of thin film growth by magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Ellmer, K.; Mientus, R.; Weiß, V.; Rossner, H.

    2001-07-01

    A novel method is described for the in situ-investigation of nucleation and growth of thin films during magnetron sputtering. Energy dispersive X-ray diffraction with synchrotron light is used for the structural analysis during film growth. An in situ-magnetron sputtering chamber was constructed and installed at a synchrotron radiation beam line with a bending magnet. The white synchrotron light (1-70 keV) passes the sputtering chamber through Kapton windows and hits one of the substrates on a four-fold sample holder. The diffracted beam, observed under a fixed diffraction angle between 3° and 10°, is energy analyzed by a high purity Ge-detector. The in situ-EDXRD setup is demonstrated for the growth of tin-doped indium oxide (ITO) films prepared by reactive magnetron sputtering from a metallic target.

  4. Analysis of nuclear materials by energy dispersive x-ray fluorescence and spectral effects of alpha decay

    SciTech Connect

    Worley, Christopher G

    2009-01-01

    Energy dispersive X-ray fluorescence (EDXRF) spectra collected from alpha emitters are complicated by artifacts inherent to the alpha decay process, particularly when using portable instruments. For example, {sup 239}Pu EDXRF spectra exhibit a prominent uranium L X-ray emission peak series due to sample alpha decay rather than source-induced X-ray fluorescence. A portable EDXRF instrument was used to collect spectra from plutonium, americium, and a Pu-contaminated steel sample. The plutonium sample was also analyzed by wavelength dispersive XRF to demonstrate spectral differences observed when using these very different instruments.

  5. Portable apparatus for in situ x-ray diffraction and fluorescence analyses of artworks.

    PubMed

    Eveno, Myriam; Moignard, Brice; Castaing, Jacques

    2011-10-01

    A portable X-ray fluorescence/X-ray diffraction (XRF/XRD) system for artwork studies has been designed constructed and tested. It is based on Debye Scherrer XRD in reflection that takes advantage of many recent improvements in the handling of X-rays (polycapillary optics; advanced two-dimensional detection). The apparatus is based on a copper anode air cooled X-ray source, and the XRD analysis is performed on a 5-20 μm thick layer from the object surface. Energy dispersive XRF elemental analysis can be performed at the same point as XRD, giving elemental compositions that support the interpretation of XRD diagrams. XRF and XRD analyses were tested to explore the quality and the limits of the analytical technique. The XRD diagrams are comparable in quality with diagrams obtained with conventional laboratory equipment. The mineral identification of materials in artwork is routinely performed with the portable XRF-XRD system. Examples are given for ceramic glazes containing crystals and for paintings where the determination of pigments is still a challenge for nondestructive analysis. For instance, lead compounds that provide a variety of color pigments can be easily identified as well as a pigment such as lapis lazuli that is difficult to identify by XRF alone. More than 70 works of art have been studied in situ in museums, monuments, etc. In addition to ceramics and paintings, these works include bronzes, manuscripts, etc., which permit improvement in the comprehension of ancient artistic techniques. PMID:21615981

  6. Combination of Raman, Infrared, and X-Ray Energy-Dispersion Spectroscopies and X-Ray Diffraction to Study a Fossilization Process

    NASA Astrophysics Data System (ADS)

    de Sousa Filho, Francisco Eduardo; da Silva, João Hermínio; Feitosa Saraiva, Antônio Álamo; Brito, Deyvid Dennys S.; Viana, Bartolomeu Cruz; de Oliveira Abagaro, Bruno Tavares; de Tarso Cavalcante Freire, Paulo

    2011-12-01

    X-ray diffraction was combined with X-ray energy-dispersion, Fourier-transform infrared, and Raman spectroscopies to study the fossilization of a Cretaceous specimen of the plant Brachyphyllum castilhoi, a fossil from the Ipubi Formation, in the Araripe Sedimentary Basin, Northeastern Brazil. Among the possible fossilization processes, which could involve pyrite, silicon oxide, calcium oxide, or other minerals, we were able to single out pyritization as the central mechanism producing the fossil, more than 100 million years ago. In addition to expanding the knowledge of the Ipubi Formation, this study shows that, when combined with other experimental techniques, Raman spectroscopy is a valuable tool at the paleontologist's disposal.

  7. Energy dispersive X-ray diffraction in the diamond anvil, high-pressure apparatus - Comparison of synchrotron and conventional X-ray sources

    NASA Technical Reports Server (NTRS)

    Spain, I. L.; Black, D. R.

    1985-01-01

    The use of both conventional fixed-anode X-ray sources and synchrotron radiation to carry out energy-dispersive X-ray diffraction experiments at high pressure in a diamond anvil cell, is discussed. The photon flux at the sample and at the detector for the two cases are compared and the results are presented in graphs. It is shown that synchrotron radiation experiments can be performed with nearly two orders of magnitude increase in data rate if superior detectors and detector electronics are available.

  8. Fast GPU-based absolute intensity determination for energy-dispersive X-ray Laue diffraction

    NASA Astrophysics Data System (ADS)

    Alghabi, F.; Send, S.; Schipper, U.; Abboud, A.; Pietsch, U.; Kolb, A.

    2016-01-01

    This paper presents a novel method for fast determination of absolute intensities in the sites of Laue spots generated by a tetragonal hen egg-white lysozyme crystal after exposure to white synchrotron radiation during an energy-dispersive X-ray Laue diffraction experiment. The Laue spots are taken by means of an energy-dispersive X-ray 2D pnCCD detector. Current pnCCD detectors have a spatial resolution of 384 × 384 pixels of size 75 × 75 μm2 each and operate at a maximum of 400 Hz. Future devices are going to have higher spatial resolution and frame rates. The proposed method runs on a computer equipped with multiple Graphics Processing Units (GPUs) which provide fast and parallel processing capabilities. Accordingly, our GPU-based algorithm exploits these capabilities to further analyse the Laue spots of the sample. The main contribution of the paper is therefore an alternative algorithm for determining absolute intensities of Laue spots which are themselves computed from a sequence of pnCCD frames. Moreover, a new method for integrating spectral peak intensities and improved background correction, a different way of calculating mean count rate of the background signal and also a new method for n-dimensional Poisson fitting are presented.We present a comparison of the quality of results from the GPU-based algorithm with the quality of results from a prior (base) algorithm running on CPU. This comparison shows that our algorithm is able to produce results with at least the same quality as the base algorithm. Furthermore, the GPU-based algorithm is able to speed up one of the most time-consuming parts of the base algorithm, which is n-dimensional Poisson fitting, by a factor of more than 3. Also, the entire procedure of extracting Laue spots' positions, energies and absolute intensities from a raw dataset of pnCCD frames is accelerated by a factor of more than 3.

  9. Analysis of energy dispersive x-ray diffraction profiles for material identification, imaging and system control

    NASA Astrophysics Data System (ADS)

    Cook, Emily Jane

    2008-12-01

    This thesis presents the analysis of low angle X-ray scatter measurements taken with an energy dispersive system for substance identification, imaging and system control. Diffraction measurements were made on illicit drugs, which have pseudo- crystalline structures and thus produce diffraction patterns comprising a se ries of sharp peaks. Though the diffraction profiles of each drug are visually characteristic, automated detection systems require a substance identification algorithm, and multivariate analysis was selected as suitable. The software was trained with measured diffraction data from 60 samples covering 7 illicit drugs and 5 common cutting agents, collected with a range of statistical qual ities and used to predict the content of 7 unknown samples. In all cases the constituents were identified correctly and the contents predicted to within 15%. Soft tissues exhibit broad peaks in their diffraction patterns. Diffraction data were collected from formalin fixed breast tissue samples and used to gen erate images. Maximum contrast between healthy and suspicious regions was achieved using momentum transfer windows 1.04-1.10 and 1.84-1.90 nm_1. The resulting images had an average contrast of 24.6% and 38.9% compared to the corresponding transmission X-ray images (18.3%). The data was used to simulate the feedback for an adaptive imaging system and the ratio of the aforementioned momentum transfer regions found to be an excellent pa rameter. Investigation into the effects of formalin fixation on human breast tissue and animal tissue equivalents indicated that fixation in standard 10% buffered formalin does not alter the diffraction profiles of tissue in the mo mentum transfer regions examined, though 100% unbuffered formalin affects the profile of porcine muscle tissue (a substitute for glandular and tumourous tissue), though fat is unaffected.

  10. Scanning electron microscope/energy dispersive x ray analysis of impact residues on LDEF tray clamps

    NASA Technical Reports Server (NTRS)

    Bernhard, Ronald P.; Durin, Christian; Zolensky, Michael E.

    1992-01-01

    To better understand the nature of particulates in low-Earth orbit (LEO), and their effects on spacecraft hardware, we are analyzing residues found in impacts on the Long Duration Exposure Facility (LDEF) tray clamps. LDEF experiment trays were held in place by 6 to 8 chromic-anodized aluminum (6061-T6) clamps that were fastened to the spacecraft frame using three stainless steel hex bolts. Each clamp exposed an area of approximately 58 sq cm (4.8 cm x 12.7 cm x .45 cm, minus the bolt coverage). Some 337 out of 774 LDEF tray clamps were archived at JSC and are available through the Meteoroid & Debris Special Investigation Group (M&D SIG). Optical scanning of clamps, starting with Bay/Row A01 and working toward H25, is being conducted at JSC to locate and document impacts as small as 40 microns. These impacts are then inspected by Scanning Electron Microscopy/Energy Dispersive X-ray Analysis (SEM/EDXA) to select those features which contain appreciable impact residue material. Based upon the composition of projectile remnants, and using criteria developed at JSC, we have made a preliminary discrimination between micrometeoroid and space debris residue-containing impact features. Presently, 13 impacts containing significant amounts of unmelted and semi-melted micrometeoritic residues were forwarded to Centre National d'Etudes Spatiales (CNES) in France. At the CNES facilities, the upgraded impacts were analyzed using a JEOL T330A SEM equipped with a NORAN Instruments, Voyager X-ray Analyzer. All residues were quantitatively characterized by composition (including oxygen and carbon) to help understand interplanetary dust as possibly being derived from comets and asteroids.

  11. Clinical applications of scanning electron microscopy and energy dispersive X-ray analysis in dermatology--an up-date

    SciTech Connect

    Forslind, B.

    1988-06-01

    Dermatological papers comprising scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis data published 1983 through 1986 in international journals are reviewed, as an update to our 1984 paper on Clinical applications of scanning electron microscopy and X-ray microanalysis in dermatology. The present paper not only deals with a review of recent publications in this area but also presents the application of microincineration to hair and cryosectioned freeze-dried skin specimens. Examples of the increased contrast obtained in hair cross sections are presented and a discussion on the feasibility of microincineration at analysis of hair and skin cross sections is given. Particle probe analysis (EDX: energy dispersive X-ray analysis and PMP: proton microprobe analysis) as applied to hair and skin samples are presented with stress put on the proton probe analysis. The complementarity of EDX and PMP is demonstrated and future applications are suggested. 75 references.

  12. Two facets of the x-ray microanalysis at low voltage: The secondary fluorescence x-rays emission and the microcalorimeter energy-dispersive spectrometer

    NASA Astrophysics Data System (ADS)

    Demers, Hendrix

    The best spatial resolution, for a microanalysis with a scanning electron microscope (SEND, is achieved by using a low voltage electron beam. But the x-ray microanalysis was developed for high electron beam energy (greater than 10 keV). Also, the specimen will often contain light and medium elements and the analyst will have to use a mixture of K, L, and sometime M x-ray peaks for the x-ray microanalysis. With a mixture of family lines, it will be common to have secondary fluorescence x-rays emission by K--L and L--K interactions. The accuracy of the fluorescence correction models presently used by the analyst are not well known for these interactions. This work shows that the modified secondary fluorescence x-rays emission correction models can improve the accuracy of the microanalysis for K--L and L--K interactions. The general equation derived in this work allows the identification of three factors which influence the secondary fluorescence x-rays emission. The fluorescence production factor epsilonƒ can be used to predict the importance of the secondary fluorescence x-rays emission. A large value of epsilonƒ indicates that a fluorescence correction is needed. Another disadvantage of using a low voltage is that there are more frequent occurrences of x-ray peaks overlap. A new microanalysis instruments that combines the high-spatial resolution and high-energy resolution for x-ray detection is needed. The microcalorimeter energy-dispersive spectrometer (muEDS) should improve the low voltage microanalysis, but the maturity of this technology has to be evaluated first. One of the first commercial muEDS for x-ray microanalysis in a SEM is studied and analyzed in this work. This commercial muEDS has an excellent energy resolution (˜ 15 eV) and can detect x-rays of low energy. This x-ray detector can be used as a high-spatial resolution and high-energy resolution microanalysis instrument. There are still hurdles that this technology must overcome before its

  13. A study of the behavior of bromide in artificial pits using in situ X-ray microprobe analysis

    SciTech Connect

    Isaacs, H.S.; Kaneko, M.

    1997-12-31

    An in situ X-ray microprobe analysis of Type 316 stainless steel artificial pits has been carried out with a bromide/chloride solution. A high intensity 8 micron diameter polychromatic X-ray beam was scanned across the steel solution interface within the artificial pit. The resulting X-ray fluorescence was analyzed using an energy dispersive X-ray detector. In contrast to the light Cl atom, Br could be detected, making it possible to monitor the behavior of halides in the artificial pits and in the salt layer at the interface. It was found that Br was more active than Cl. At high potentials, elemental Br was produced as an oxidation product, whereas without added bromide, chloride only formed a salt layer. Br also concentrated at the salt steel interface at potentials below where it was oxidized.

  14. Elemental analysis of mining wastes by energy dispersive X-ray fluorescence (EDXRF)

    NASA Astrophysics Data System (ADS)

    Gonzalez-Fernandez, O.; Queralt, I.; Carvalho, M. L.; Garcia, G.

    2007-08-01

    An energy dispersive X-ray fluorescence (EDXRF) tri-axial geometry experimental spectrometer has been employed to determine the concentrations of 13 different elements (K, Ca, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Rb, Sr and Pb) in mine wastes from different depths of two mine tailings from the Cartagena-La Union (Spain) mining district. The elements were determined and quantified using the fundamental parameters method. The concentrations of Cr, Ni, Cu, Zn and Pb were compared to the values from the European and Spanish legislation to evaluate the environmental risk and to classify the wastes as inert wastes or as wastes that have to be control land-filled. The results obtained demonstrate that these wastes can be considered as inert for the considered elements, apart from the concentration levels of Zn and Pb. Whilst Zn slightly overpasses the regulatory levels, Pb mean value exceeds three to six times the value to be considered as Class I potential land-filling material.

  15. An energy dispersive x-ray scattering and molecular dynamics study of liquid dimethyl carbonate

    NASA Astrophysics Data System (ADS)

    Gontrani, Lorenzo; Russina, Olga; Marincola, Flaminia Cesare; Caminiti, Ruggero

    2009-12-01

    In this work, we report on the first x-ray diffraction study on liquid dimethyl carbonate. Diffraction spectra were collected with an energy-dispersive instrument, whose wide Q-range allows the structure determination of weakly ordered systems (such as liquids). The structural correlation in this liquid ranges up to about 20 Å. The observed patterns are interpreted with a structural model derived from classical molecular dynamics simulations. The simulations were run using OPLS force field, only slightly modified to restrain bond distances to the experimental values. The model structure function and radial distribution functions, averaged among the productive trajectory frames, are in very good agreement with the corresponding experimental ones. Molecular dynamics results show that the deviations from C2v cis-cis structure, predicted by ab initio calculations and observed by electron diffraction in the gas phase, are small. By analyzing the intra- and intermolecular pair distribution functions, it was possible to assign the peaks of the experimental radial distribution function to specific structural correlations, and to compute the different average intermolecular coordination numbers. The intermolecular methyl-carbonyl oxygen distance is thoroughly discussed to assess the presence of weak C-H⋯ṡO hydrogen bonds.

  16. Microcalorimeter-type energy dispersive X-ray spectrometer for a transmission electron microscope.

    PubMed

    Hara, Toru; Tanaka, Keiichi; Maehata, Keisuke; Mitsuda, Kazuhisa; Yamasaki, Noriko Y; Ohsaki, Mitsuaki; Watanabe, Katsuaki; Yu, Xiuzhen; Ito, Takuji; Yamanaka, Yoshihiro

    2010-01-01

    A new energy dispersive X-ray spectrometer (EDS) with a microcalorimeter detector equipped with a transmission electron microscope (TEM) has been developed for high- accuracy compositional analysis in the nanoscale. A superconducting transition-edge-sensor-type microcalorimeter is applied as the detector. A cryogen-free cooling system, which consists of a mechanical and a dilution refrigerator, is selected to achieve long-term temperature stability. In order to mount these detector and refrigerators on a TEM, the cooling system is specially designed such that these two refrigerators are separated. Also, the detector position and arrangement are carefully designed to avoid adverse affects between the superconductor detector and the TEM lens system. Using the developed EDS system, at present, an energy resolution of 21.92 eV full-width-at-half maximum has been achieved at the Cr K alpha line. This value is about seven times better than that of the current typical commercial Si(Li) detector, which is usually around 140 eV. The developed microcalorimeter EDS system can measure a wide energy range, 1-20 keV, at one time with this high energy resolution that can resolve peaks from most of the elements. Although several further developments will be needed to enable practical use, highly accurate compositional analysis with high energy resolution will be realized by this microcalorimeter EDS system. PMID:19717388

  17. High temperature monitoring of silicon carbide ceramics by confocal energy dispersive X-ray fluorescence spectrometry

    NASA Astrophysics Data System (ADS)

    Li, Fangzuo; Liu, Zhiguo; Sun, Tianxi

    2016-04-01

    In the present work, we presented an alternative method for monitoring of the oxidation situation of silicon carbide (SiC) ceramics at various high temperatures in air by measuring the Compton-to-Rayleigh intensity ratios (ICo/IRa) and effective atomic numbers (Zeff) of SiC ceramics with the confocal energy dispersive X-ray fluorescence (EDXRF) spectrometer. A calibration curve of the relationship between ICo/IRa and Zeff was established by using a set of 8 SiC calibration samples. The sensitivity of this approach is so high that it can be easily distinguished samples of Zeff differing from each other by only 0.01. The linear relationship between the variation of Zeff and the variations of contents of C, Si and O of SiC ceramics were found, and the corresponding calculation model of the relationship between the ΔZ and the ΔCC, ΔCSi, and ΔCO were established. The variation of contents of components of the tested SiC ceramics after oxidation at high temperature was quantitatively calculated based on the model. It was shown that the results of contents of carbon, silicon and oxygen obtained by this method were in good agreement with the results obtained by XPS, giving values of relative deviation less than 1%. It was concluded that the practicality of this proposed method for monitoring of the oxidation situation of SiC ceramics at high temperatures was acceptable.

  18. Micro energy-dispersive x-ray fluorescence spectrometry study of dentin coating with nanobiomaterials

    NASA Astrophysics Data System (ADS)

    Soares, Luís. Eduardo Silva; Nahorny, Sídnei; Marciano, Fernanda Roberta; Zanin, Hudson; Lobo, Anderson de Oliveira

    2015-06-01

    New biomaterials such as multi-walled carbon nanotubes oxide/graphene oxide (MWCNTO/GO), nanohydroxyapatite (nHAp) and combination of them together or not to acidulated phosphate fluoride gel (F) have been tested as protective coating before root dentin erosion. Fourteen bovine teeth were cleaned, polished, divided into two parts (n=28) and assigned to seven groups: (Control) - without previous surface treatment; F treatment; nHAp; MWCNTO/GO; F+nHAp; F+MWCNTO/GO and F+MWCNTO/GO/nHAp composites. Each sample had two sites of pre-treatments: acid etched area and an area without treatment. After the biomaterials application, the samples were submitted to six cycles (demineralization: orange juice, 10 min; remineralization: artificial saliva, 1 h). Micro energy-dispersive X-ray fluorescence spectrometry (μ-EDXRF) mapping area analyses were performed after erosive cycling on both sites (n=84). μ-EDXRF mappings showed that artificial saliva and MWCNTO/GO/nHAp/F composite treatments produced lower dentin demineralization than in the other groups. Exposed dentin tubules allowed better interaction of nanobiomaterials than in smear layer covered dentin. Association of fluoride with other biomaterials had a positive influence on acid etched dentin. MWCNTO/GO/nHAp/F composite treatment resulted in levels of demineralization similar to the control group.

  19. Multi-element analysis of pyrite ores using polarized energy-dispersive X-ray fluorescence spectrometry.

    PubMed

    Ustündağ, Zafer; Ustündağ, Ilknur; Kağan Kadioğlu, Yusuf

    2007-07-01

    X-ray fluorescence (XRF) spectrometry is used worldwide in geological material analysis. This study, applies polarized energy-dispersive X-ray fluorescence (PEDXRF) Spectrometer and compares in the samples of Rize-Cayeli and Mardin pyrite ores. The samples of pyrite ore were collected from the Rize and Mardin in Turkey. The prepared samples were analyzed using a PEDXRF spectrometer. The result of the analysis shows the presence of many elements including rare-earth elements (from Na to Th). The accuracy and precision of the technique for chemical analysis is demonstrated by analyzing USGS standards, GEOL, GBW 7109 and GBW-7309 sediment. PMID:17459714

  20. Backscattered electron imaging and windowless energy dispersive x-ray microanalysis: a new technique for gallstone analysis

    SciTech Connect

    Kaufman, H.S.; Lillemoe, K.D.; Magnuson, T.H.; Frasca, P.; Pitt, H.A. )

    1990-12-01

    Scanning electron microscopy with or without conventional energy dispersive x-ray microanalysis is currently used to identify gallstone microstructure and inorganic composition. Organic calcium salts are among many biliary constituents thought to have a role in gallstone nidation and growth. However, current analytical techniques which identify these salts are destructive and compromise gallstone microstructural data. We have developed a new technique for gallstone analysis which provides simultaneous structural and compositional identification of calcium salts within gallstones. Backscattered electron imaging is used to localize calcium within cholesterol at minimum concentrations of 0.01%. Windowless energy dispersive x-ray microanalysis produces elemental spectra of gallstone calcium salts which are qualitatively and quantitatively different. These combined techniques provide simultaneous structural and compositional information obtained from intact gallstone cross-sections and have been used to identify calcium salts in gallstones obtained at cholecystectomy from 106 patients.

  1. Characterization of Japanese color sticks by energy dispersive X-ray fluorescence, X-ray diffraction and Fourier transform infrared analysis

    NASA Astrophysics Data System (ADS)

    Manso, M.; Valadas, S.; Pessanha, S.; Guilherme, A.; Queralt, I.; Candeias, A. E.; Carvalho, M. L.

    2010-04-01

    This work comprises the use of energy dispersive X-ray fluorescence (EDXRF), X-ray diffraction (XRD) and Fourier transformed infrared (FTIR) techniques for the study of the composition of twentieth century traditional Japanese color sticks. By using the combination of analytical techniques it was possible to obtain information on inorganic and organic pigments, binders and fillers present in the sticks. The colorant materials identified in the sticks were zinc and titanium white, chrome yellow, yellow and red ochre, vermillion, alizarin, indigo, Prussian and synthetic ultramarine blue. The results also showed that calcite and barite were used as inorganic mineral fillers while Arabic gum was the medium used. EDXRF offered great potential for such investigations since it allowed the identification of the elements present in the sample preserving its integrity. However, this information alone was not enough to clearly identify some of the materials in study and therefore it was necessary to use XRD and FTIR techniques.

  2. In situ x-ray reflectivity and grazing incidence x-ray diffraction study of L 1(0) ordering in (57)Fe/Pt multilayers.

    PubMed

    Raghavendra Reddy, V; Gupta, Ajay; Gome, Anil; Leitenberger, Wolfram; Pietsch, U

    2009-05-01

    In situ high temperature x-ray reflectivity and grazing incidence x-ray diffraction measurements in the energy dispersive mode are used to study the ordered face-centered tetragonal (fct) L 1(0) phase formation in [Fe(19 Å)/Pt(25 Å)]( × 10) multilayers prepared by ion beam sputtering. With the in situ x-ray measurements it is observed that (i) the multilayer structure first transforms to a disordered FePt and subsequently to an ordered fct L 1(0) phase, (ii) the ordered fct L 1(0) FePt peaks start to appear at 320 °C annealing, (iii) the activation energy of the interdiffusion is 0.8 eV and (iv) ordered fct FePt grains have preferential out-of-plane texture. The magneto-optical Kerr effect and conversion electron Mössbauer spectroscopies are used to study the magnetic properties of the as-deposited and 400 °C annealed multilayers. The magnetic data for the 400 °C annealed sample indicate that the magnetization is at an angle of ∼50° from the plane of the film. PMID:21825468

  3. ENERGY-DISPERSIVE, X-RAY REFLECTIVITY DENSITY MEASUREMENTS OF POROUS SIO2 XEROGELS

    EPA Science Inventory

    X-ray reflectivity has been used to nondestructively measure the density of thin, porous, SiO2-based xerogels. Critical angle, defined by total external reflection, was measured for multiple x-ray energies to correct for sample misalignment error in me determination of the densit...

  4. [Influence of the Experiment Energy Dispersive X-Ray Fluorescence Measurement of Uranium by Different Excitation Source].

    PubMed

    Xiong, Chao; Ge, Liang-quan; Liu, Duan; Zhang, Qing-xian; Gu, Yi; Luo, Yao-yao; Zhao, Jian-kun

    2016-03-01

    Aiming at the self-excitation effect on the interference of measurements which exist in the process of Energy dispersive X-ray fluorescence method for uranium measurement. To solve the problem of radioactive isotopes only used as excitation source in determination of uranium. Utilizing the micro X-ray tube to test Self-excitation effect to get a comparison of the results obtained by three different uranium ore samples--109 Cd, 241 Am and Mirco X-ray tube. The results showed that self-excitation effect produced the area measure of characteristic X-ray peak is less than 1% of active condition, also the interference of measurements can be negligible. Photoelectric effect cross-section excited by 109 Cd is higher, corresponding fluorescence yield is higher than excited by 241 Am as well due to characteristics X-ray energy of 109 Cd, 22.11 & 24.95 KeV adjacent to absorption edge energy of L(α), 21.75 KeV, based on the above, excitation efficiency by 109 Cd is higher than 241 Am; The fact that measurement error excited by 241 Am is significantly greater than by 109 Cd is mainly due to peak region overlap between L energy peaks of uranium and Scattering peak of 241 Am, 26.35 keV, These factors above caused the background of measured Spectrum higher; The error between the uranium content in ore samples which the X-ray tube as the excitation source and the chemical analysis results is within 10%. Conclusion: This paper come to the conclusion that the technical quality of uranium measurement used X-ray tube as excitation source is superior to that in radioactive source excitation mode. PMID:27400534

  5. Standardless Quantitative Electron-Excited X-ray Microanalysis by Energy-Dispersive Spectrometry: What Is Its Proper Role?

    PubMed

    Newbury

    1998-11-01

    : Electron beam X-ray microanalysis with semiconductor energy-dispersive spectrometry (EDS) performed with standards and calculated matrix corrections can yield quantitative results with a distribution such that 95% of analyses fall within +/-5% relative for major and minor constituents. Standardless methods substitute calculations for the standard intensities, based either on physical models of X-ray generation and propagation (first principles) or on mathematical fits to remotely measured standards (fitted standards). Error distributions have been measured for three different standardless analysis procedures with a suite of microanalysis standards including metal alloys, glasses, minerals, ceramics, and stoichiometric compounds. For the first-principles standardless procedure, the error distribution placed 95% of analyses within +/-50% relative, whereas for two commercial fitted standards procedures, the error distributions placed 95% of analyses within +/-25% relative. The implication of these error distributions for the accuracy of analytical results is considered, and recommendations for the use of standardless analysis are given. PMID:10087281

  6. Standardless Quantitative Electron-Excited X-ray Microanalysis by Energy-Dispersive Spectrometry: What Is Its Proper Role?

    NASA Astrophysics Data System (ADS)

    Newbury, Dale E.

    1998-11-01

    : Electron beam X-ray microanalysis with semiconductor energy-dispersive spectrometry (EDS) performed with standards and calculated matrix corrections can yield quantitative results with a distribution such that 95% of analyses fall within ±5% relative for major and minor constituents. Standardless methods substitute calculations for the standard intensities, based either on physical models of X-ray generation and propagation (first principles) or on mathematical fits to remotely measured standards (fitted standards). Error distributions have been measured for three different standardless analysis procedures with a suite of microanalysis standards including metal alloys, glasses, minerals, ceramics, and stoichiometric compounds. For the first-principles standardless procedure, the error distribution placed 95% of analyses within ±50% relative, whereas for two commercial fitted standards procedures, the error distributions placed 95% of analyses within ±25% relative. The implication of these error distributions for the accuracy of analytical results is considered, and recommendations for the use of standardless analysis are given.

  7. Low energy x-ray spectra measured with a mercuric iodide energy dispersive spectrometer in a scanning electron microscope

    SciTech Connect

    Iwanczyk, J.S.; Dabrowski, A.J.; Huth, G.C.; Bradley, J.G.; Conley, J.M.; Albee, A.L.

    1985-01-01

    A mercuric iodide energy dispersive x-ray spectrometer, with Peltier cooling provided for the detector and input field effect transistor, has been developed and tested in a scanning electron microscope. X-ray spectra were obtained with the 15 keV electron beam. An energy resolution of 225 eV (FWHM) for Mn-K/sub ..cap alpha../ at 5.9 keV and 195 eV (FWHM) for Mg-K line at 1.25 keV has been measured. Overall system noise level was 175 eV (FWHM). The detector system characterization with a carbon target demonstrated good energy sensitivity at low energies and lack of significant spectral artifacts at higher energies. 16 refs., 5 figs.

  8. Low energy X-ray spectra measured with a mercuric iodide energy dispersive spectrometer in a scanning electron microscope

    NASA Technical Reports Server (NTRS)

    Iwanczyk, J. S.; Dabrowski, A. J.; Huth, G. C.; Bradley, J. G.; Conley, J. M.

    1986-01-01

    A mercuric iodide energy dispersive X-ray spectrometer, with Peltier cooling provided for the detector and input field effect transistor, has been developed and tested in a scanning electron microscope. X-ray spectra were obtained with the 15 keV electron beam. An energy resolution of 225 eV (FWHM) for Mn-K(alpha) at 5.9 keV and 195 eV (FWHM) for the Mg-K line at 1.25 keV has been measured. Overall system noise level was 175 eV (FWHM). The detector system characterization with a carbon target demonstrated good energy sensitivity at low energies and lack of significant spectral artifacts at higher energies.

  9. Probing Heterogeneous Chemistry of Individual Atmospheric Particles Using Scanning Electron Microscopy and Energy-Dispersive X-ray Analysis

    SciTech Connect

    Krueger, Brenda J.; Grassian, Vicki H.; Iedema, Martin J.; Cowin, James P.; Laskin, Alexander

    2003-10-01

    In this paper, we demonstrate the utility of single-particle analysis to investigate the chemistry of isolated, individual particles of atmospheric relevance such as NaCl, sea salt, CaCO3, and SiO2. A variety of state-of-th-art scanning electron microscopy techniques, including environmental scanning electon microscopy and computer-controlled scanning electron microscopy/energy-dispersive X-ray analysis, were utilized for monitoring and quantifying phase transitions of individual particles, morphology, and compositional changes of individual particles as they react with nitric acid.

  10. A new background subtraction method for energy dispersive X-ray fluorescence spectra using a cubic spline interpolation

    NASA Astrophysics Data System (ADS)

    Yi, Longtao; Liu, Zhiguo; Wang, Kai; Chen, Man; Peng, Shiqi; Zhao, Weigang; He, Jialin; Zhao, Guangcui

    2015-03-01

    A new method is presented to subtract the background from the energy dispersive X-ray fluorescence (EDXRF) spectrum using a cubic spline interpolation. To accurately obtain interpolation nodes, a smooth fitting and a set of discriminant formulations were adopted. From these interpolation nodes, the background is estimated by a calculated cubic spline function. The method has been tested on spectra measured from a coin and an oil painting using a confocal MXRF setup. In addition, the method has been tested on an existing sample spectrum. The result confirms that the method can properly subtract the background.

  11. Benzyne-functionalized graphene and graphite characterized by Raman spectroscopy and energy dispersive X-ray analysis

    PubMed Central

    Magedov, Igor V.; Frolova, Lilia V.; Ovezmyradov, Mekan; Bethke, Donald; Shaner, Eric A.; Kalugin, Nikolai G.

    2012-01-01

    The benzyne functionalization of chemical vapor deposition grown large area graphene and graphite was performed using a mixture of o-trimethylsilylphenyl triflate and cesium fluoride that react with the carbon surface. The reaction requires at least 2 days of treatment before the appearance of Raman and energy-dispersive X-ray spectral signatures that verify modification. Raman spectra of modified graphene and graphite show a rich structure of lines corresponding to C=C-C, C-H, and low frequency modes of surface-attached benzyne rings. PMID:23505324

  12. Dose-rate controlled energy dispersive x-ray spectroscopic mapping of the metallic components in a biohybrid nanosystem

    NASA Astrophysics Data System (ADS)

    Zhu, Yuanyuan; Munro, Catherine J.; Olszta, Matthew J.; Edwards, Danny J.; Braunschweig, Adam B.; Knecht, Marc R.; Browning, Nigel D.

    2016-08-01

    In this work, we showcase that through precise control of the electron dose rate, state-of-the-art large solid angle energy dispersive x-ray spectroscopy mapping in aberration-corrected scanning transmission electron microscope is capable of faithful and unambiguous chemical characterization of the Pt and Pd distribution in a peptide-mediated nanosystem. This low-dose-rate recording scheme adds another dimension of flexibility to the design of elemental mapping experiments, and holds significant potential for extending its application to a wide variety of beam sensitive hybrid nanostructures.

  13. A semianalytic model to extract differential linear scattering coefficients of breast tissue from energy dispersive x-ray diffraction measurements

    SciTech Connect

    LeClair, Robert J.; Boileau, Michel M.; Wang Yinkun

    2006-04-15

    The goal of this work is to develop a technique to measure the x-ray diffraction signals of breast biopsy specimens. A biomedical x-ray diffraction technology capable of measuring such signals may prove to be of diagnostic use to the medical field. Energy dispersive x-ray diffraction measurements coupled with a semianalytical model were used to extract the differential linear scattering coefficients [{mu}{sub s}(x)] of breast tissues on absolute scales. The coefficients describe the probabilities of scatter events occurring per unit length of tissue per unit solid angle of detection. They are a function of the momentum transfer argument, x=sin({theta}/2)/{lambda}, where {theta}=scatter angle and {lambda}=incident wavelength. The technique was validated by using a 3 mm diameter 50 kV polychromatic x-ray beam incident on a 5 mm diameter 5 mm thick sample of water. Water was used because good x-ray diffraction data are available in the literature. The scatter profiles from 6 deg. to 15 deg. in increments of 1 deg. were measured with a 3 mmx3 mmx2 mm thick cadmium zinc telluride detector. A 2 mm diameter Pb aperture was placed on top of the detector. The target to detector distance was 29 cm and the duration of each measurement was 10 min. Ensemble averages of the results compare well with the gold standard data of A. H. Narten [''X-ray diffraction data on liquid water in the temperature range 4 deg. C-200 deg. C, ORNL Report No. 4578 (1970)]. An average 7.68% difference for which most of the discrepancies can be attributed to the background noise at low angles was obtained. The preliminary measurements of breast tissue are also encouraging.

  14. Electro-deposition of Cu studied with in situ electrochemical scanning transmission x-ray microscopy

    NASA Astrophysics Data System (ADS)

    Hitchcock, A. P.; Qin, Z.; Rosendahl, S. M.; Lee, V.; Reynolds, M.; Hosseinkhannazer, H.

    2016-01-01

    Soft X-ray scanning transmission X-ray microscopy (STXM) was used to investigate Cu deposition onto, and stripping from a Au surface. Cu 2p spectromicroscopy was used to analyze initial and final states (ex situ processing) and follow the processes in situ. The in situ experiments were carried out using a static electrochemical cell with an electrolyte layer thickness of ˜1 μm. A new apparatus for in situ electrochemical STXM is described.

  15. Note: High-pressure in situ x-ray laminography using diamond anvil cell.

    PubMed

    Nomura, Ryuichi; Uesugi, Kentaro

    2016-04-01

    A high-pressure in situ X-ray laminography technique was developed using a newly designed, laterally open diamond anvil cell. A low X-ray beam of 8 keV energy was used, aiming at future application to dual energy X-ray chemical imaging techniques. The effects of the inclination angle and the imaging angle range were evaluated at ambient pressure using the apparatus. Sectional images of ruby ball samples were successfully reconstructed at high pressures, up to approximately 50 GPa. The high-pressure in situ X-ray laminography technique is expected to provide new insights into the deep Earth sciences. PMID:27131721

  16. Note: High-pressure in situ x-ray laminography using diamond anvil cell

    NASA Astrophysics Data System (ADS)

    Nomura, Ryuichi; Uesugi, Kentaro

    2016-04-01

    A high-pressure in situ X-ray laminography technique was developed using a newly designed, laterally open diamond anvil cell. A low X-ray beam of 8 keV energy was used, aiming at future application to dual energy X-ray chemical imaging techniques. The effects of the inclination angle and the imaging angle range were evaluated at ambient pressure using the apparatus. Sectional images of ruby ball samples were successfully reconstructed at high pressures, up to approximately 50 GPa. The high-pressure in situ X-ray laminography technique is expected to provide new insights into the deep Earth sciences.

  17. Methodology toward 3D micro X-ray fluorescence imaging using an energy dispersive charge-coupled device detector.

    PubMed

    Garrevoet, Jan; Vekemans, Bart; Tack, Pieter; De Samber, Björn; Schmitz, Sylvia; Brenker, Frank E; Falkenberg, Gerald; Vincze, Laszlo

    2014-12-01

    A new three-dimensional (3D) micro X-ray fluorescence (μXRF) methodology based on a novel 2D energy dispersive CCD detector has been developed and evaluated at the P06 beamline of the Petra-III storage ring (DESY) in Hamburg, Germany. This method is based on the illumination of the investigated sample cross-section by a horizontally focused beam (vertical sheet beam) while fluorescent X-rays are detected perpendicularly to the sheet beam by a 2D energy dispersive (ED) CCD detector allowing the collection of 2D cross-sectional elemental images of a certain depth within the sample, limited only by signal self-absorption effects. 3D elemental information is obtained by a linear scan of the sample in the horizontal direction across the vertically oriented sheet beam and combining the detected cross-sectional images into a 3D elemental distribution data set. Results of the 3D μXRF analysis of mineral inclusions in natural deep Earth diamonds are presented to illustrate this new methodology. PMID:25346101

  18. Total reflection X-ray fluorescence and energy-dispersive X-ray fluorescence analysis of runoff water and vegetation from abandoned mining of Pb Zn ores

    NASA Astrophysics Data System (ADS)

    Marques, A. F.; Queralt, I.; Carvalho, M. L.; Bordalo, M.

    2003-12-01

    The present work reports on the heavy metal content: Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Cd and Pb in running waters and vegetation around abandoned mining areas. Two species of mosses ( Dicranum sp. and Pleurocarpus sp.) and three different species of wild grass ( Bromus sp., Rumex sp. and Pseudoavena sp.) growing on the surrounding areas of old lead-zinc mines (Aran Valley, Pyrenees, NE Spain) have been analyzed. Both water and vegetation were collected in two different sampling places: (a) near the mine gallery water outlets and (b) on the landfill close to the abandoned mineral concentration factories. For the heavy metal content determination, two different techniques were used: total reflection X-ray fluorescence for water analysis and energy-dispersive X-ray fluorescence for vegetation study. Surface waters around mine outlets exhibit anomalous content of Co, Ni, Zn, Cd. Stream waters running on mining landfills exhibit higher Cu, Zn, Cd and Pb than those of the waters at the mine gallery outlets. The results allow us to assess the extent of the environmental impact of the mining activities on the water quality. The intake of these elements by vegetation was related with the sampling place, reflecting the metal water content and the substrate chemistry. Accumulation of metals in mosses is higher than those exhibited in wild grasses. Furthermore, different levels of accumulation were found in different wild grass. Rumex sp. presented the lowest metal concentrations, while Pseudoavena sp. reported the highest metal content.

  19. Design and Performance of a TES X-ray Microcalorimeter Array for Energy Dispersive Spectroscopy on Scanning Transmission Electron Microscope

    NASA Astrophysics Data System (ADS)

    Muramatsu, Haruka; Nagayoshi, K.; Hayashi, T.; Sakai, K.; Yamamoto, R.; Mitsuda, K.; Yamasaki, N. Y.; Maehata, K.; Hara, T.

    2016-07-01

    We discuss the design and performance of a transition edge sensor (TES) X-ray microcalorimeter array for scanning transmission electron microscope (STEM)-energy dispersive X-ray spectroscopy (EDS). The TES X-ray microcalorimeter has better energy resolution compared to conventional silicon drift detector and STEM-EDS utilizing a TES detector makes it possible to map the distribution of elements on a specimen in addition to analyze the composition. The requirement for a TES detector is a high counting rate (>20 kcps), wide energy band (0.5-15 keV) and good energy resolution (<10 eV) full width at half maximum. The major improvement of this development is to increase the maximum counting rate. In order to accommodate the high counting rate, we adopted an 8 × 8 format, 64-pixel array and common biasing scheme for the readout method. We did all design and fabrication of the device in house. With the device we have fabricated most recently, the pulse decay time is 40 \\upmu s which is expected to achieve 50 kcps. For a single pixel, the measured energy resolution was 7.8 eV at 5.9 keV. This device satisfies the requirements of counting rate and energy resolution, although several issues remain where the performance must be confirmed.

  20. Bulk substrate porosity verification by applying Monte Carlo modeling and Castaing's formula using energy-dispersive x-rays

    NASA Astrophysics Data System (ADS)

    Yung, Lai Chin; Fei, Cheong Choke; Mandeep, Jit Singh; Amin, Nowshad; Lai, Khin Wee

    2015-11-01

    The leadframe fabrication process normally involves additional thin-metal layer plating on the bulk copper substrate surface for wire bonding purposes. Silver, tin, and copper flakes are commonly adopted as plating materials. It is critical to assess the density of the plated metal layer, and in particular to look for porosity or voids underneath the layer, which may reduce the reliability during high-temperature stress. A fast, reliable inspection technique is needed to assess the porosity or void weakness. To this end, the characteristics of x-rays generated from bulk samples were examined using an energy-dispersive x-ray (EDX) detector to examine the porosity percentage. Monte Carlo modeling was integrated with Castaing's formula to verify the integrity of the experimental data. Samples with different porosity percentages were considered to test the correlation between the intensity of the collected x-ray signal and the material density. To further verify the integrity of the model, conventional cross-sectional samples were also taken to observe the porosity percentage using Image J software measurement. A breakthrough in bulk substrate assessment was achieved by applying EDX for the first time to nonelemental analysis. The experimental data showed that the EDX features were not only useful for elemental analysis, but also applicable to thin-film metal layer thickness measurement and bulk material density determination. A detailed experiment was conducted using EDX to assess the plating metal layer and bulk material porosity.

  1. Design and Performance of a TES X-ray Microcalorimeter Array for Energy Dispersive Spectroscopy on Scanning Transmission Electron Microscope

    NASA Astrophysics Data System (ADS)

    Muramatsu, Haruka; Nagayoshi, K.; Hayashi, T.; Sakai, K.; Yamamoto, R.; Mitsuda, K.; Yamasaki, N. Y.; Maehata, K.; Hara, T.

    2016-02-01

    We discuss the design and performance of a transition edge sensor (TES) X-ray microcalorimeter array for scanning transmission electron microscope (STEM)-energy dispersive X-ray spectroscopy (EDS). The TES X-ray microcalorimeter has better energy resolution compared to conventional silicon drift detector and STEM-EDS utilizing a TES detector makes it possible to map the distribution of elements on a specimen in addition to analyze the composition. The requirement for a TES detector is a high counting rate (> 20 kcps), wide energy band (0.5-15 keV) and good energy resolution (< 10 eV) full width at half maximum. The major improvement of this development is to increase the maximum counting rate. In order to accommodate the high counting rate, we adopted an 8 × 8 format, 64-pixel array and common biasing scheme for the readout method. We did all design and fabrication of the device in house. With the device we have fabricated most recently, the pulse decay time is 40 \\upmu s which is expected to achieve 50 kcps. For a single pixel, the measured energy resolution was 7.8 eV at 5.9 keV. This device satisfies the requirements of counting rate and energy resolution, although several issues remain where the performance must be confirmed.

  2. Design and Performance of a TES X-ray Microcalorimeter Array for Energy Dispersive Spectroscopy on Scanning Transmission Electron Microscope

    NASA Astrophysics Data System (ADS)

    Muramatsu, Haruka; Nagayoshi, K.; Hayashi, T.; Sakai, K.; Yamamoto, R.; Mitsuda, K.; Yamasaki, N. Y.; Maehata, K.; Hara, T.

    2016-07-01

    We discuss the design and performance of a transition edge sensor (TES) X-ray microcalorimeter array for scanning transmission electron microscope (STEM)-energy dispersive X-ray spectroscopy (EDS). The TES X-ray microcalorimeter has better energy resolution compared to conventional silicon drift detector and STEM-EDS utilizing a TES detector makes it possible to map the distribution of elements on a specimen in addition to analyze the composition. The requirement for a TES detector is a high counting rate (>20 kcps), wide energy band (0.5-15 keV) and good energy resolution (<10 eV) full width at half maximum. The major improvement of this development is to increase the maximum counting rate. In order to accommodate the high counting rate, we adopted an 8 × 8 format, 64-pixel array and common biasing scheme for the readout method. We did all design and fabrication of the device in house. With the device we have fabricated most recently, the pulse decay time is 40 μs which is expected to achieve 50 kcps. For a single pixel, the measured energy resolution was 7.8 eV at 5.9 keV. This device satisfies the requirements of counting rate and energy resolution, although several issues remain where the performance must be confirmed.

  3. Electrochemical in-situ reaction cell for X-ray scattering, diffraction and spectroscopy

    SciTech Connect

    Braun, Artur; Granlund, Eric; Cairns, Elton J.

    2003-01-27

    An electrochemical in-situ reaction cell for hard X-ray experiments with battery electrodes is described. Applications include the small angle scattering, diffraction, and near-edge spectroscopy of lithium manganese oxide electrodes.

  4. Detector solid angle formulas for use in x-ray energy dispersive spectrometry.

    SciTech Connect

    Zaluzec, N. J.; Materials Science Division

    2009-01-01

    With the advent of silicon drift X-ray detectors, a range of new geometries has become possible in electron optical columns. Because of their compact size, these detectors can potentially achieve high geometrical collection efficiencies; however, using traditional approximations detector solid angle calculations rapidly break down and at times can yield nonphysical values. In this article we present generalized formulas that can be used to calculate the variation in detection solid angle for contemporary Si(Li) as well as new silicon drift configurations.

  5. Electron probe energy dispersive X-ray microanalysis (EDXA) in the investigation of fossil bone: the case of Java man.

    PubMed

    Bartsiokas, A; Day, M H

    1993-05-22

    Doubts about the attribution of the Trinil femur to Homo erectus on anatomical grounds have a long history. Here, for the first time, published stratigraphic information and chemical evidence based on the Ca/P ratios confirm that the anatomical doubts are justified. The Trinil femur apparently belongs to a more recent stratum above the 'fossil layer' (Hauptknochenschicht, HK) in which the Trinil calotte was found. It is concluded that the Trinil Femur I belongs to Homo sapiens, whereas the Trinil Femora II-V and the calotte belong to H. erectus. The chemical evidence derives from the use of electron probe energy dispersive X-ray microanalysis (EDXA), a technique that can be virtually non-destructive and therefore may be used on scarce fossil evidence. PMID:8391701

  6. Energy dispersive x-ray analysis of the cornea. Application to paraffin sections of normal and diseased corneas

    SciTech Connect

    Robinson, M.R.; Streeten, B.W.

    1984-11-01

    The distribution of chemical elements in the normal human cornea was studied by energy dispersive x-ray analysis and scanning electron microscopy of routinely prepared paraffin sections. Calcium, phosphorus, and sulfur were consistently present in quantities above background and varied in concentration regionally. Analysis of fresh-frozen tissue, an approximation of the in vivo state, gave a similar elemental profile to paraffin sections, except for the loss of diffusable electrolytes in the latter. After fixation, S was the most abundant element and was highest in Descemet's membrane. Corneas with granular, lattice, macular, and Fuchs endothelial dystrophies, band keratopathy, and spheroidal degeneration were also examined. Characteristic patterns of abnormal S and Ca distribution were found in each of the dystrophies. The relative proportions of Ca, P, and S gave diagnostic profiles for distinguishing band keratopathy and spheroidal degeneration.

  7. Energy dispersive X-ray spectroscopy analysis of Si sidewall surface etched by deep-reactive ion etching

    NASA Astrophysics Data System (ADS)

    Matsutani, Akihiro; Nishioka, Kunio; Sato, Mina

    2016-06-01

    We investigated the composition of a passivation film on a sidewall etched by deep-reactive ion etching (RIE) using SF6/O2 and C4F8 plasma, by energy-dispersive X-ray (EDX) spectroscopy. It was found that the compositions of carbon and fluorine in the passivation film on the etched sidewall depend on the width and depth of the etched trench. It is important to understand both the plasma behavior and the passivation film composition to carry out fabrication by deep-RIE. We consider that these results of the EDX analysis of an etched sidewall will be useful for understanding plasma behavior in order to optimize the process conditions of deep-RIE.

  8. Sodium lauryl sulfate enhances nickel penetration through guinea-pig skin. Studies with energy dispersive X-ray microanalysis

    SciTech Connect

    Lindberg, M.; Sagstroem, S.R.; Roomans, G.M.; Forslind, B.

    1989-03-01

    The effect of sodium lauryl sulphate (SLS), a common ingredient of detergents, on the penetration of nickel through the stratum corneum in the guinea-pig skin model was studied with energy dispersive X-ray microanalysis (EDX) to evaluate the barrier-damaging properties of this common detergent. The EDX technique allows a simultaneous determination of physiologically important elements, e.g., Na, Mg, P, Cl, K, Ca and S in addition to Ni at each point of measurement in epidermal cell strata. Our results show that SLS reduces the barrier function to Ni-ion penetration of the stratum corneum. In addition we have shown that EDX allows analysis of the influence of different factors involved in nickel penetration through the skin by giving data on the physiological effects on the epidermal cells caused by the applied substances.

  9. Trace elemental analysis of school chalk using energy dispersive X-ray florescence spectroscopy (ED-XRF)

    SciTech Connect

    Maruthi, Y. A.; Das, N. Lakshmana; Ramprasad, S.; Ram, S. S.; Sudarshan, M.

    2015-08-28

    The present studies focus the quantitative analysis of elements in school chalk to ensure the safety of its use. The elements like Calcium (Ca), Aluminum (Al), Iron (Fe), Silicon (Si) and Chromium (Cr) were analyzed from settled chalk dust samples collected from five classrooms (CD-1) and also from another set of unused chalk samples collected from local market (CD-2) using Energy Dispersive X-Ray florescence(ED-XRF) spectroscopy. Presence of these elements in significant concentrations in school chalk confirmed that, it is an irritant and occupational hazard. It is suggested to use protective equipments like filtered mask for mouth, nose and chalk holders. This study also suggested using the advanced mode of techniques like Digital boards, marker boards and power point presentations to mitigate the occupational hazard for classroom chalk.

  10. Trace elemental analysis of school chalk using energy dispersive X-ray florescence spectroscopy (ED-XRF)

    NASA Astrophysics Data System (ADS)

    Maruthi, Y. A.; Das, N. Lakshmana; Ramprasad, S.; Ram, S. S.; Sudarshan, M.

    2015-08-01

    The present studies focus the quantitative analysis of elements in school chalk to ensure the safety of its use. The elements like Calcium (Ca), Aluminum (Al), Iron (Fe), Silicon (Si) and Chromium (Cr) were analyzed from settled chalk dust samples collected from five classrooms (CD-1) and also from another set of unused chalk samples collected from local market (CD-2) using Energy Dispersive X-Ray florescence(ED-XRF) spectroscopy. Presence of these elements in significant concentrations in school chalk confirmed that, it is an irritant and occupational hazard. It is suggested to use protective equipments like filtered mask for mouth, nose and chalk holders. This study also suggested using the advanced mode of techniques like Digital boards, marker boards and power point presentations to mitigate the occupational hazard for classroom chalk

  11. Dendrochemical patterns of calcium, zinc, and potassium related to internal factors detected by energy dispersive X-ray fluorescence (EDXRF)

    USGS Publications Warehouse

    Smith, Kevin T.; Balouet, Jean Christophe; Shortle, Walter C.; Chalot, Michel; Beaujard, François; Grudd, Håkan; Vroblesky, Don A.; Burkem, Joel G.

    2014-01-01

    Energy dispersive X-ray fluorescence (EDXRF) provides highly sensitive and precise spatial resolution of cation content in individual annual growth rings in trees. The sensitivity and precision have prompted successful applications to forensic dendrochemistry and the timing of environmental releases of contaminants. These applications have highlighted the need to distinguish dendrochemical effects of internal processes from environmental contamination. Calcium, potassium, and zinc are three marker cations that illustrate the influence of these processes. We found changes in cation chemistry in tree rings potentially due to biomineralization, development of cracks or checks, heartwood/sapwood differentiation, intra-annual processes, and compartmentalization of infection. Distinguishing internal from external processes that affect dendrochemistry will enhance the value of EDXRF for both physiological and forensic investigations.

  12. Non-destructive analysis of didymium and praseodymium molybdate crystals using energy dispersive X-ray fluorescence technique

    NASA Astrophysics Data System (ADS)

    Bhat, C. K.; Joseph, Daisy; Pandita, Sanjay; Kotru, P. N.

    2016-08-01

    Analysis of didymium (Di) and praseodymium molybdate crystals were carried out using energy dispersive X-ray fluorescence (EDXRF). The assigned empirical chemical formulae of the composites were tested and verified by the EDXRF technique by estimating experimental major elemental concentration ratios. On the Basis of these ratios, the established formulae for some of the composite materials have been verified and suggestions made for their refinement. Non-destructive technique used in this analysis enables to retain the original crystal samples and makes rapid simultaneous scan of major elements such as La, Pr, Ned and Mo as well as impurities such as Ce. Absence of samarium(Sm) in the spectrum during analysis of didymium molybdate crystals indicated an incomplete growth of mixed rare earth single crystal. These crystals (e.g.,Di) are shown to be of modified stoichiometry with Ce as trace impurity.

  13. Dendrochemical patterns of calcium, zinc, and potassium related to internal factors detected by energy dispersive X-ray fluorescence (EDXRF).

    PubMed

    Smith, Kevin T; Balouet, Jean Christophe; Shortle, Walter C; Chalot, Michel; Beaujard, François; Grudd, Håkan; Vroblesky, Don A; Burken, Joel G

    2014-01-01

    Energy dispersive X-ray fluorescence (EDXRF) provides highly sensitive and precise spatial resolution of cation content in individual annual growth rings in trees. The sensitivity and precision have prompted successful applications to forensic dendrochemistry and the timing of environmental releases of contaminants. These applications have highlighted the need to distinguish dendrochemical effects of internal processes from environmental contamination. Calcium, potassium, and zinc are three marker cations that illustrate the influence of these processes. We found changes in cation chemistry in tree rings potentially due to biomineralization, development of cracks or checks, heartwood/sapwood differentiation, intra-annual processes, and compartmentalization of infection. Distinguishing internal from external processes that affect dendrochemistry will enhance the value of EDXRF for both physiological and forensic investigations. PMID:24034830

  14. Measurement of Trace Constituents by Electron-Excited X-Ray Microanalysis with Energy-Dispersive Spectrometry.

    PubMed

    Newbury, Dale E; Ritchie, Nicholas W M

    2016-06-01

    Electron-excited X-ray microanalysis performed with scanning electron microscopy and energy-dispersive spectrometry (EDS) has been used to measure trace elemental constituents of complex multielement materials, where "trace" refers to constituents present at concentrations below 0.01 (mass fraction). High count spectra measured with silicon drift detector EDS were quantified using the standards/matrix correction protocol embedded in the NIST DTSA-II software engine. Robust quantitative analytical results for trace constituents were obtained from concentrations as low as 0.000500 (mass fraction), even in the presence of significant peak interferences from minor (concentration 0.01≤C≤0.1) and major (C>0.1) constituents. Limits of detection as low as 0.000200 were achieved in the absence of peak interference. PMID:27329308

  15. Energy-dispersive X-ray diffraction using an annular beam.

    PubMed

    Dicken, A J; Evans, J P O; Rogers, K D; Greenwood, C; Godber, S X; Prokopiou, D; Stone, N; Clement, J G; Lyburn, I; Martin, R M; Zioupos, P

    2015-05-18

    We demonstrate material phase identification by measuring polychromatic diffraction spots from samples at least 20 mm in diameter and up to 10 mm thick with an energy resolving point detector. Within our method an annular X-ray beam in the form of a conical shell is incident with its symmetry axis normal to an extended polycrystalline sample. The detector is configured to receive diffracted flux transmitted through the sample and is positioned on the symmetry axis of the annular beam. We present the experiment data from a range of different materials and demonstrate the acquisition of useful data with sub-second collection times of 0.5 s; equating to 0.15 mAs. Our technique should be highly relevant in fields that demand rapid analytical methods such as medicine, security screening and non-destructive testing. PMID:26074592

  16. Energy dispersive X-ray analysis of titanium dioxide nanoparticle distribution after intravenous and subcutaneous injection in mice.

    PubMed

    Patri, Anil; Umbreit, Thomas; Zheng, J; Nagashima, K; Goering, Peter; Francke-Carroll, Sabine; Gordon, Edward; Weaver, James; Miller, Terry; Sadrieh, Nakissa; McNeil, Scott; Stratmeyer, Mel

    2009-11-01

    In an effort to understand the disposition and toxicokinetics of nanoscale materials, we used EDS (energy dispersive X-ray spectroscopy) to detect and map the distribution of titanium dioxide (TiO2) in tissue sections from mice following either subcutaneous (s.c.) or intravenous (i.v.) injection. TiO2 nanoparticles were administered at a dose of 560 mg/kg (i.v.) or 5600 mg/kg (s.c.) to Balb/c female mice on two consecutive days. Tissues (liver, kidney, lung, heart, spleen, and brain) were examined by light microscopy, TEM (transmission electron microscopy), SEM (scanning electron microscopy), and EDS following necropsy one day after treatment. Particle agglomerates were detected by light microscopy in all tissues examined, EDS microanalysis was used to confirm that these tissues contained elemental titanium and oxygen. The TEM micrographs and EDS spectra of the aggregates were compared with in vitro measurements of TiO2 nanoparticle injection solution (i.e., in water). The nanoparticles were also characterized using dynamic light scattering in water, 10 mM NaCl, and phosphate buffered saline (PBS). In low ionic strength solvents (water and 10 mM NaCl), the TiO2 particles had average hydrodynamic diameters ranging from 114-122 nm. In PBS, however, the average diameter increases to 1-2 microm, likely due to aggregation analogous to that observed in tissue by TEM and EDS. This investigation demonstrates the suitability of energy dispersive X-ray spectroscopy (EDS) for detection of nanoparticle aggregates in tissues and shows that disposition of TiO2 nanoparticles depends on the route of administration (i.v. or s.c.). PMID:19626582

  17. Energy dispersive X-ray microanalysis, fluoride release, and antimicrobial properties of glass ionomer cements indicated for atraumatic restorative treatment

    PubMed Central

    Saxena, Sudhanshu; Tiwari, Sonia

    2016-01-01

    Aim: The aim of this study was to compare constituents of glass powder, fluoride release, and antimicrobial properties of new atraumatic restorative treatment material with zirconia fillers and conventional glass ionomer cement (GIC) type IX. Materials and Methods: Thisin vitro study comparing Zirconomer and Fuji IX was executed in three parts: (1) energy dispersive X-ray microanalysis of glass powders (2) analysis of fluoride release at 1st, 3rd, 7th, 15th, and 30th day, and (3) antimicrobial activity against Streptococcus mutans, Lactobacillus casei, and Candida albicans at 48 hours. Data was analyzed using unpaired t-test and two way analysis of variance followed by least significant difference post hoc test. A P value of < 0.05 was considered statistically significant. Results: Energy dispersive X-ray microanalysis revealed that, in both Zirconomer and Fuji IX glass powders, mean atomic percentage of oxygen was more than 50%. According to the weight percentage, zirconium in Zirconomer and silica in Fuji IX were the second main elements. Calcium, zinc, and zirconium were observed only in Zirconomer. At all the time intervals, statistically significant higher amount of fluoride release was observed with Zirconomer than Fuji IX. At 48 hours, mean ± standard deviation (SD) of zone of inhibition against Streptococcus mutans was 11.14 ± 0.77 mm and 8.51 ± 0.43 mm for Zirconomer and Fuji IX, respectively. Against Lactobacillus casei, it was 14.06 ± 0.71 mm for Zirconomer and 11.70 ± 0.39 mm for Fuji IX. No antifungal activity was observed against Candida albicans by Zirconomer and Fuji IX. Conclusion: Zirconomer had higher antibacterial activity against Streptococcus mutans and Lactobacillus casei, which may be attributed to its composition and higher fluoride release. However, it failed to show antifungal effect againstCandida albicans. PMID:27583226

  18. Determination of selenium at trace levels in geologic materials by energy-dispersive X-ray fluorescence spectrometry

    USGS Publications Warehouse

    Wahlberg, J.S.

    1981-01-01

    Low levels of selenium (0.1-500 ppm) in both organic and inorganic geologic materials can be semiquantitatively measured by isolating Se as a thin film for presentation to an energy-dispersive X-ray fluorescence spectrometer. Suitably pulverized samples are first digested by fusing with a mixture of Na2CO3 and Na2O2. The fusion cake is dissolved in distilled water, buffered with NH4Cl, and filtered to remove Si and the R2O3 group. A carrier solution of Na2TeO4, plus solid KI, hydrazine sulfate and Na2SO3, is added to the filtrate. The solution is then vacuum-filtered through a 0.45-??m pore-size filter disc. The filter, with the thin film of precipitate, is supported between two sheets of Mylar?? film for analysis. Good agreement is shown between data reported in this study and literature values reported by epithermal neutron-activation analysis and spectrofluorimetry. The method can be made quantitative by utilizing a secondary precipitation to assure complete recovery of the Se. The X-ray method offers fast turn-around time and a reasonably high production rate. ?? 1981.

  19. Gold nephropathy. Ultrastructural, fluorescent, and energy-dispersive x-ray microanalysis study

    SciTech Connect

    Ainsworth, S.K.; Swain, R.P.; Watabe, N.; Brackett, N.C. Jr.; Pilia, P.; Hennigar, G.R.

    1981-07-01

    The nephrotic syndrome developed in a patient receiving therapy with gold for rheumatoid arthritis. The results of a histopathological examination of the renal biopsy specimen were unremarkable. Immunofluorescent studies showed deposits of immunoglobulins and C3 in a granular pattern in the glomerular basement membranes. Ultrastructurally, the discrete osmiophilic immune complexes were epimembranous. By x-ray microanalysis, gold that was complexed with sulfur was present in proximal tubular cytoplasmic vacuoles and nuclei. Gold and sulfur could not be demonstrated in glomerular epimembranous deposits. The results of these studies suggest that immune complex deposition does not involve gold and sulfur acting as haptens. Gold-salt therapy may result in damage to proximal tubules that leak renal tubular antigens, which in turn complex with autoantibody and produce an autoimmune membranous nephropathy. The evidence for this mechanism is not convincing. Although the data indicate an immune-complex cause for gold-salt nephropathy, the incident antigen (or antigens) and mechanism of action remain unidentified.

  20. Effect of x-ray energy dispersion in digital subtraction imaging at the iodine K-edge--A Monte Carlo study

    SciTech Connect

    Prino, F.; Ceballos, C.; Cabal, A.; Sarnelli, A.; Gambaccini, M.; Ramello, L.

    2008-01-15

    The effect of the energy dispersion of a quasi-monochromatic x-ray beam on the performance of a dual-energy x-ray imaging system is studied by means of Monte Carlo simulations using MCNPX (Monte Carlo N-Particle eXtended) version 2.6.0. In particular, the case of subtraction imaging at the iodine K-edge, suitable for angiographic imaging application, is investigated. The average energies of the two beams bracketing the iodine K-edge are set to the values of 31.2 and 35.6 keV corresponding to the ones obtained with a compact source based on a conventional x-ray tube and a mosaic crystal monochromator. The energy dispersion of the two beams is varied between 0 and 10 keV of full width at half-maximum (FWHM). The signal and signal-to-noise ratio produced in the simulated images by iodine-filled cavities (simulating patient vessels) drilled in a PMMA phantom are studied as a function of the x-ray energy dispersion. The obtained results show that, for the considered energy separation of 4.4 keV, no dramatic deterioration of the image quality is observed with increasing x-ray energy dispersion up to a FWHM of about 2.35 keV. The case of different beam energies is also investigated by means of fast simulations of the phantom absorption.

  1. Scanning force microscope for in situ nanofocused X-ray diffraction studies

    PubMed Central

    Ren, Zhe; Mastropietro, Francesca; Davydok, Anton; Langlais, Simon; Richard, Marie-Ingrid; Furter, Jean-Jacques; Thomas, Olivier; Dupraz, Maxime; Verdier, Marc; Beutier, Guillaume; Boesecke, Peter; Cornelius, Thomas W.

    2014-01-01

    A compact scanning force microscope has been developed for in situ combination with nanofocused X-ray diffraction techniques at third-generation synchrotron beamlines. Its capabilities are demonstrated on Au nano-islands grown on a sapphire substrate. The new in situ device allows for in situ imaging the sample topography and the crystallinity by recording simultaneously an atomic force microscope (AFM) image and a scanning X-ray diffraction map of the same area. Moreover, a selected Au island can be mechanically deformed using the AFM tip while monitoring the deformation of the atomic lattice by nanofocused X-ray diffraction. This in situ approach gives access to the mechanical behavior of nanomaterials. PMID:25178002

  2. In situ/operando soft x-ray spectroscopy characterization of ion solvation and catalysis

    NASA Astrophysics Data System (ADS)

    Liu, Yi-Sheng; Guo, Jinghua

    Many important systems especially in energy-related regime are based on the complexity of material architecture, chemistry and interactions among constituents within. To understand and thus ultimately control the varying applications calls for in-situ/operando characterization tools. We will present the recent development of the in-situ/operando soft X-ray spectroscopic in the studies of catalytic and alkali ion solvation under bias condition, and reveal how to overcome the challenge that soft X-rays cannot easily peek into the high-pressure catalytic cells or liquid electrochemical cells. Also the different feasible detection approaches can provide surface and bulk sensitivity experimentally from those in-situ cells. The unique design of in-situ/operando soft X-ray spectroscopy instrumentation and fabrication principle with examples in Ca, Na, Mg based solutions at ambient pressure/temperature and high temperature (~250°C) gas catalysis will be shown.

  3. Energy dispersive X-ray fluorescence spectroscopy/Monte Carlo simulation approach for the non-destructive analysis of corrosion patina-bearing alloys in archaeological bronzes: The case of the bowl from the Fareleira 3 site (Vidigueira, South Portugal)

    NASA Astrophysics Data System (ADS)

    Bottaini, C.; Mirão, J.; Figuereido, M.; Candeias, A.; Brunetti, A.; Schiavon, N.

    2015-01-01

    Energy dispersive X-ray fluorescence (EDXRF) is a well-known technique for non-destructive and in situ analysis of archaeological artifacts both in terms of the qualitative and quantitative elemental composition because of its rapidity and non-destructiveness. In this study EDXRF and realistic Monte Carlo simulation using the X-ray Monte Carlo (XRMC) code package have been combined to characterize a Cu-based bowl from the Iron Age burial from Fareleira 3 (Southern Portugal). The artifact displays a multilayered structure made up of three distinct layers: a) alloy substrate; b) green oxidized corrosion patina; and c) brownish carbonate soil-derived crust. To assess the reliability of Monte Carlo simulation in reproducing the composition of the bulk metal of the objects without recurring to potentially damaging patina's and crust's removal, portable EDXRF analysis was performed on cleaned and patina/crust coated areas of the artifact. Patina has been characterized by micro X-ray Diffractometry (μXRD) and Back-Scattered Scanning Electron Microscopy + Energy Dispersive Spectroscopy (BSEM + EDS). Results indicate that the EDXRF/Monte Carlo protocol is well suited when a two-layered model is considered, whereas in areas where the patina + crust surface coating is too thick, X-rays from the alloy substrate are not able to exit the sample.

  4. Electrochemical cell for in-situ x-ray characterization

    SciTech Connect

    Doughty, D.H.; Ingersoll, D.; Rodriguez, M.A.

    1998-08-04

    An electrochemical cell suitable for in-situ XRD analysis is presented. Qualitative information such as phase formation and phase stability can be easily monitored using the in-situ cell design. Quantitative information such as lattice parameters and kinetic behavior is also straightforward. Analysis of the LiMn&sub2;O&sub4; spinel using this cell design shows that the lattice undergoes two major structural shrinkages at approx. 4.0 V and approx. 4.07 V during charging. These shrinkages correlate well with the two electrochemical waves observed and indicate the likelihood of two separate redox processes which charging and discharging.

  5. In situ X-ray microprobe study of salt layers during anodic dissolution of stainless steel in chloride solution

    SciTech Connect

    Isaacs, H.S.; Cho, J.H.; Rivers, M.L.; Sutton, S.R.

    1995-04-01

    Salt layers play an important role in many electrochemical dissolution processes. The composition of salt films formed on austenitic stainless steel have, for the first time, been determined using in situ energy dispersive X-ray fluorescence microanalysis during dissolution in a chloride solution. The electrode was the cross section of a nickel/chromium steel foil sandwiched between plastic sheets. The foil was electrochemically dissolved producing a pit 1.6 mm deep. The electrode configuration simulated localized corrosion with a one-dimensional diffusion geometry. X-ray fluorescence intensities of chromium K{sub {alpha}}, iron K{sub {alpha}}, an nickel K{sub {beta}} energies were measured as the steel/solution interface traversed a 6 {mu}m, polychromatic, high-intensity X-ray beam. Qualitative determinations were made of the composition of the salt layer and the composition of the saturated solution. Salt layer thickness was found to increase with increased applied potentials. The salt layer was found to be rich in iron and depleted in nickel and, particularly, chromium. The effective diffusion coefficients of the dissolved species were determined from the composition of the saturated solution at the interface. Nickel showed the highest and chromium the lowest effective diffusion coefficient.

  6. DIBENZYLAMMONIUM AND SODIUM DIBENZYLDITHIOCARBAMATES AS PRECIPITANTS FOR PRECONCENTRATION OF TRACE ELEMENTS IN WATER FOR ANALYSIS BY ENERGY DISPERSIVE X-RAY FLUORESCENCE

    EPA Science Inventory

    Precipitation with combined dibenzylammonium dibenzyldithiocarbamate and sodium dibenzyldithiocarbamate at pH 5.0 can be used to separate 22 trace elements from water. Membrane filtration on the precipitate yielded a thin sample, suitable for analysis by energy dispersive X-ray f...

  7. An atomic layer deposition chamber for in situ x-ray diffraction and scattering analysis

    SciTech Connect

    Geyer, Scott M.; Methaapanon, Rungthiwa; Kim, Woo-Hee; Bent, Stacey F.; Johnson, Richard W.; Van Campen, Douglas G.; Metha, Apurva

    2014-05-15

    The crystal structure of thin films grown by atomic layer deposition (ALD) will determine important performance properties such as conductivity, breakdown voltage, and catalytic activity. We report the design of an atomic layer deposition chamber for in situ x-ray analysis that can be used to monitor changes to the crystal structural during ALD. The application of the chamber is demonstrated for Pt ALD on amorphous SiO{sub 2} and SrTiO{sub 3} (001) using synchrotron-based high resolution x-ray diffraction, grazing incidence x-ray diffraction, and grazing incidence small angle scattering.

  8. A portable X-ray diffraction apparatus for in situ analyses of masters' paintings

    NASA Astrophysics Data System (ADS)

    Eveno, Myriam; Duran, Adrian; Castaing, Jacques

    2010-09-01

    It is rare that the analyses of materials in paintings can be carried out by taking micro-samples. Valuable works of art are best studied in situ by non-invasive techniques. For that purpose, a portable X-ray diffraction and fluorescence apparatus has been designed and constructed at the C2RMF. This apparatus has been used for paintings of Rembrandt, Leonardo da Vinci, Van Gogh, Mantegna, etc. Results are given to illustrate the performance of X-ray diffraction, especially when X-ray fluorescence does not bring sufficient information to conclude.

  9. Exposure and analysis of microparticles embedded in silica aerogel keystones using NF3-mediated electron beam-induced etching and energy-dispersive X-ray spectroscopy

    NASA Astrophysics Data System (ADS)

    Martin, Aiden A.; Lin, Ting; Toth, Milos; Westphal, Andrew J.; Vicenzi, Edward P.; Beeman, Jeffrey; Silver, Eric H.

    2016-07-01

    In 2006, NASA's Stardust spacecraft delivered to Earth dust particles collected from the coma of comet 81P/Wild 2, with the goal of furthering the understanding of solar system formation. Stardust cometary samples were collected in a low-density, nanoporous silica aerogel making their study technically challenging. This article demonstrates the identification, exposure, and elemental composition analysis of particles analogous to those collected by NASA's Stardust mission using in-situ SEM techniques. Backscattered electron imaging is shown by experimental observation and Monte Carlo simulation to be suitable for locating particles of a range of sizes relevant to Stardust (down to submicron diameters) embedded within silica aerogel. Selective removal of the silica aerogel encapsulating an embedded particle is performed by cryogenic NF3-mediated electron beam-induced etching. The porous, low-density nature of the aerogel results in an enhanced etch rate compared with solid material, making it an effective, nonmechanical method for the exposure of particles. After exposure, elemental composition of the particle was analyzed by energy-dispersive X-ray spectroscopy using a high spectral resolution microcalorimeter. Signals from fluorine contamination are shown to correspond to nonremoved silica aerogel and only in residual concentrations.

  10. Exposure and analysis of microparticles embedded in silica aerogel keystones using NF3-mediated electron beam-induced etching and energy-dispersive X-ray spectroscopy

    NASA Astrophysics Data System (ADS)

    Martin, Aiden A.; Lin, Ting; Toth, Milos; Westphal, Andrew J.; Vicenzi, Edward P.; Beeman, Jeffrey; Silver, Eric H.

    2016-04-01

    In 2006, NASA's Stardust spacecraft delivered to Earth dust particles collected from the coma of comet 81P/Wild 2, with the goal of furthering the understanding of solar system formation. Stardust cometary samples were collected in a low-density, nanoporous silica aerogel making their study technically challenging. This article demonstrates the identification, exposure, and elemental composition analysis of particles analogous to those collected by NASA's Stardust mission using in-situ SEM techniques. Backscattered electron imaging is shown by experimental observation and Monte Carlo simulation to be suitable for locating particles of a range of sizes relevant to Stardust (down to submicron diameters) embedded within silica aerogel. Selective removal of the silica aerogel encapsulating an embedded particle is performed by cryogenic NF3-mediated electron beam-induced etching. The porous, low-density nature of the aerogel results in an enhanced etch rate compared with solid material, making it an effective, nonmechanical method for the exposure of particles. After exposure, elemental composition of the particle was analyzed by energy-dispersive X-ray spectroscopy using a high spectral resolution microcalorimeter. Signals from fluorine contamination are shown to correspond to nonremoved silica aerogel and only in residual concentrations.

  11. In-situ X-ray diffraction system using sources and detectors at fixed angular positions

    DOEpatents

    Gibson, David M.; Gibson, Walter M.; Huang, Huapeng

    2007-06-26

    An x-ray diffraction technique for measuring a known characteristic of a sample of a material in an in-situ state. The technique includes using an x-ray source for emitting substantially divergent x-ray radiation--with a collimating optic disposed with respect to the fixed source for producing a substantially parallel beam of x-ray radiation by receiving and redirecting the divergent paths of the divergent x-ray radiation. A first x-ray detector collects radiation diffracted from the sample; wherein the source and detector are fixed, during operation thereof, in position relative to each other and in at least one dimension relative to the sample according to a-priori knowledge about the known characteristic of the sample. A second x-ray detector may be fixed relative to the first x-ray detector according to the a-priori knowledge about the known characteristic of the sample, especially in a phase monitoring embodiment of the present invention.

  12. In situ anodization of aluminum surfaces studied by x-ray reflectivity and electrochemical impedance spectroscopy

    SciTech Connect

    Bertram, F. Evertsson, J.; Messing, M. E.; Mikkelsen, A.; Lundgren, E.; Zhang, F.; Pan, J.; Carlà, F.; Nilsson, J.-O.

    2014-07-21

    We present results from the anodization of an aluminum single crystal [Al(111)] and an aluminum alloy [Al 6060] studied by in situ x-ray reflectivity, in situ electrochemical impedance spectroscopy and ex situ scanning electron microscopy. For both samples, a linear increase of oxide film thickness with increasing anodization voltage was found. However, the slope is much higher in the single crystal case, and the break-up of the oxide film grown on the alloy occurs at a lower anodization potential than on the single crystal. The reasons for these observations are discussed as are the measured differences observed for x-ray reflectivity and electrochemical impedance spectroscopy.

  13. In situ anodization of aluminum surfaces studied by x-ray reflectivity and electrochemical impedance spectroscopy

    NASA Astrophysics Data System (ADS)

    Bertram, F.; Zhang, F.; Evertsson, J.; Carlà, F.; Pan, J.; Messing, M. E.; Mikkelsen, A.; Nilsson, J.-O.; Lundgren, E.

    2014-07-01

    We present results from the anodization of an aluminum single crystal [Al(111)] and an aluminum alloy [Al 6060] studied by in situ x-ray reflectivity, in situ electrochemical impedance spectroscopy and ex situ scanning electron microscopy. For both samples, a linear increase of oxide film thickness with increasing anodization voltage was found. However, the slope is much higher in the single crystal case, and the break-up of the oxide film grown on the alloy occurs at a lower anodization potential than on the single crystal. The reasons for these observations are discussed as are the measured differences observed for x-ray reflectivity and electrochemical impedance spectroscopy.

  14. Distribution of toxic elements in teeth treated with amalgam using μ-energy dispersive X-ray fluorescence

    NASA Astrophysics Data System (ADS)

    Guerra, M.; Ferreira, C.; Carvalho, M. L.; Santos, J. P.; Pessanha, S.

    2016-08-01

    Over the years, the presence of mercury in amalgam fillings has raised some safety concerns. Amalgam is one of the most commonly used tooth fillings and contains approximately 50% of elemental mercury and 50% of other metals, mostly silver, tin and copper. Amalgam can release small amounts of mercury vapor over time, and patients can absorb these vapors by inhaling or ingesting them. In this study, 10 human teeth treated with dental amalgam were analyzed using energy dispersive X-ray fluorescence (EDXRF) to study the diffusion of its constituents, Ag, Cu, Sn and Hg. The used EDXRF setup, makes use of a polycapillary lens to focus radiation up to 25 μm allowing the mapping of the elemental distribution in the samples. Quantification was performed using the inbuilt software based on the Fundamental Parameters method for bulk samples, considering a hydroxyapatite matrix. The teeth were longitudinally cut and each slice was scanned from the surface enamel to the inner region (dentin and pulp cavity). Mercury concentration profiles show strong levels of this element close to the amalgam region, decreasing significantly in the dentin, and increasing again up to 40,000 μg·g- 1 in the cavity were the pulp used to exist when the tooth was vital.

  15. Atomic-scale Chemical Imaging and Quantification of Metallic Alloy Structures by Energy-Dispersive X-ray Spectroscopy

    PubMed Central

    Lu, Ping; Zhou, Lin; Kramer, M. J.; Smith, David J.

    2014-01-01

    Determination of atomic-scale crystal structure for nanostructured intermetallic alloys, such as magnetic alloys containing Al, Ni, Co (alnico) and Fe, is crucial for understanding physical properties such as magnetism, but technically challenging due to the small interatomic distances and the similar atomic numbers. By applying energy-dispersive X-ray spectroscopy (EDS) mapping to the study of two intermetallic phases of an alnico alloy resulting from spinodal decomposition, we have determined atomic-scale chemical composition at individual lattice sites for the two phases: one is the B2 phase with Fe0.76Co0.24 -Fe0.40Co0.60 ordering and the other is the L21 phase with Ni0.48Co0.52 at A-sites, Al at BΙ-sites and Fe0.20Ti0.80 at BΙΙ-sites, respectively. The technique developed through this study represents a powerful real-space approach to investigate structure chemically at the atomic scale for a wide range of materials systems. PMID:24492747

  16. Scanning Electron Microscopy Findings With Energy-Dispersive X-ray Investigations of Cosmetically Tinted Contact Lenses

    PubMed Central

    Hotta, Fumika; Imai, Shoji; Miyamoto, Tatsuro; Mitamura-Aizawa, Sayaka; Mitamura, Yoshinori

    2015-01-01

    Objective: To investigate the surfaces and principal elements of the colorants of cosmetically tinted contact lenses (Cos-CLs). Methods: We analyzed the surfaces and principal elements of the colorants of five commercially available Cos-CLs using scanning electron microscopy with energy-dispersive x-ray analysis. Results: In two Cos-CLs, the anterior and posterior surfaces were smooth, and colorants were found inside the lens. One lens showed colorants located to a depth of 8 to 14 μm from the anterior side of the lens. In the other lens, colorants were found in the most superficial layer on the posterior surface, although a coated layer was observed. The colorants in the other three lenses were deposited on either lens surface. Although a print pattern was uniform in embedded type lenses, uneven patterns were apparent in dot-matrix design lenses. Colorants used in all lenses contained chlorine, iron, and titanium. In the magnified scanning electron microscopy images of a certain lens, chlorine is exuded and spread. Conclusions: Cosmetically tinted contact lenses have a wide variety of lens surfaces and colorants. Colorants may be deposited on the lens surface and consist of an element that has tissue toxicity. PMID:25799458

  17. Atomic-scale chemical imaging and quantification of metallic alloy structures by energy-dispersive X-ray spectroscopy.

    PubMed

    Lu, Ping; Zhou, Lin; Kramer, M J; Smith, David J

    2014-01-01

    Determination of atomic-scale crystal structure for nanostructured intermetallic alloys, such as magnetic alloys containing Al, Ni, Co (alnico) and Fe, is crucial for understanding physical properties such as magnetism, but technically challenging due to the small interatomic distances and the similar atomic numbers. By applying energy-dispersive X-ray spectroscopy (EDS) mapping to the study of two intermetallic phases of an alnico alloy resulting from spinodal decomposition, we have determined atomic-scale chemical composition at individual lattice sites for the two phases: one is the B2 phase with Fe0.76Co0.24 -Fe0.40Co0.60 ordering and the other is the L2(1) phase with Ni0.48Co0.52 at A-sites, Al at B(Ι)-sites and Fe0.20Ti0.80 at B(ΙΙ)-sites, respectively. The technique developed through this study represents a powerful real-space approach to investigate structure chemically at the atomic scale for a wide range of materials systems. PMID:24492747

  18. NASA Li/CF(x) cell problem analysis: Scanning electron microscopy with energy dispersive x ray spectrometry

    NASA Technical Reports Server (NTRS)

    Baker, John

    1991-01-01

    An analysis was made of Lithium/carbon fluoride cell parts for possible chloride contamination induced by exposure to thionyl chloride (SOCl2); various samples were submitted for analysis. Only a portion of the analysis which has been conducted is covered, herein, namely analysis by scanning electron microscopy with energy dispersive x ray spectrometry (SEM/EDS). A strip of nickel was exposed to SOCl2 vapors to observe variations in surface concentrations of sulfur and chlorine with time. By detecting chlorine one can not infer contamination by SOCl2 only that contamination is present. Six samples of stainless steel foil were analyzed for chlorine using EDS. Chlorine was not detected on background samples but was detected on the samples which had been handled including those which had been cleaned. Cell covers suspected of being contaminated while in storage and covers which were not exposed to the same storage conditions were analyzed for chlorine. Although no chlorine was found on the covers from cells, it was found on all stored covers. Results are presented with techniques shown for analysis and identification. Relevant photomicrographs are presented.

  19. In-situ observations of catalytic surface reactions with soft x-rays under working conditions

    NASA Astrophysics Data System (ADS)

    Toyoshima, Ryo; Kondoh, Hiroshi

    2015-03-01

    Catalytic chemical reactions proceeding on solid surfaces are an important topic in fundamental science and industrial technologies such as energy conversion, pollution control and chemical synthesis. Complete understanding of the heterogeneous catalysis and improving its efficiency to an ultimate level are the eventual goals for many surface scientists. Soft x-ray is one of the prime probes to observe electronic and structural information of the target materials. Most studies in surface science using soft x-rays have been performed under ultra-high vacuum conditions due to the technical limitation, though the practical catalytic reactions proceed under ambient pressure conditions. However, recent developments of soft x-ray based techniques operating under ambient pressure conditions have opened a door to the in-situ observation of materials under realistic environments. The near-ambient-pressure x-ray photoelectron spectroscopy (NAP-XPS) using synchrotron radiation enables us to observe the chemical states of surfaces of condensed matters under the presence of gas(es) at elevated pressures, which has been hardly conducted with the conventional XPS technique. Furthermore, not only the NAP-XPS but also ambient-pressure compatible soft x-ray core-level spectroscopies, such as near-edge absorption fine structure (NEXAFS) and x-ray emission spectroscopy (XES), have been significantly contributing to the in-situ observations. In this review, first we introduce recent developments of in-situ observations using soft x-ray techniques and current status. Then we present recent new findings on catalytically active surfaces using soft x-ray techniques, particularly focusing on the NAP-XPS technique. Finally we give a perspective on the future direction of this emerging technique.

  20. Setup for in situ x-ray diffraction study of swift heavy ion irradiated materials

    SciTech Connect

    Kulriya, P. K.; Singh, F.; Tripathi, A.; Ahuja, R.; Kothari, A.; Dutt, R. N.; Mishra, Y. K.; Kumar, Amit; Avasthi, D. K.

    2007-11-15

    An in situ x-ray diffraction (XRD) setup is designed and installed in the materials science beam line of the Pelletron accelerator at the Inter-University Accelerator Centre for in situ studies of phase change in swift heavy ion irradiated materials. A high vacuum chamber with suitable windows for incident and diffracted X-rays is integrated with the goniometer and the beamline. Indigenously made liquid nitrogen (LN{sub 2}) temperature sample cooling unit is installed. The snapshots of growth of particles with fluence of 90 MeV Ni ions were recorded using in situ XRD experiment, illustrating the potential of this in situ facility. A thin film of C{sub 60} was used to test the sample cooling unit. It shows that the phase of the C{sub 60} film transforms from a cubic lattice (at room temperature) to a fcc lattice at around T=255 K.

  1. Probing electrode/electrolyte interfaces in situ by X-ray spectroscopies: old methods, new tricks.

    PubMed

    Wu, Cheng Hao; Weatherup, Robert S; Salmeron, Miquel B

    2015-11-11

    Electrode/electrolyte interfaces play a vital role in various electrochemical systems, but in situ characterization of such buried interfaces remains a major challenge. Several efforts to develop techniques or to modify existing techniques to study such interfaces are showing great promise to overcome this challenge. Successful examples include electrochemical scanning tunneling microscopy (EC-STM), surface-sensitive vibrational spectroscopies, environmental transmission electron microscopy (E-TEM), and surface X-ray scattering. Other techniques such as X-ray core-level spectroscopies are element-specific and chemical-state-specific, and are being widely applied in materials science research. Herein we showcase four types of newly developed strategies to probe electrode/electrolyte interfaces in situ with X-ray core-level spectroscopies. These include the standing wave approach, the meniscus approach, and two liquid cell approaches based on X-ray photoelectron spectroscopy and soft X-ray absorption spectroscopy. These examples demonstrate that with proper modifications, many ultra-high-vacuum based techniques can be adapted to study buried electrode/electrolyte interfaces and provide interface-sensitive, element- and chemical-state-specific information, such as solute distribution, hydrogen-bonding network, and molecular reorientation. At present, each method has its own specific limitations, but all of them enable in situ and operando characterization of electrode/electrolyte interfaces that can provide important insights into a variety of electrochemical systems. PMID:26514115

  2. Functional materials analysis using in situ and in operando X-ray and neutron scattering.

    PubMed

    Peterson, Vanessa K; Papadakis, Christine M

    2015-03-01

    In situ and in operando studies are commonplace and necessary in functional materials research. This review highlights recent developments in the analysis of functional materials using state-of-the-art in situ and in operando X-ray and neutron scattering and analysis. Examples are given covering a number of important materials areas, alongside a description of the types of information that can be obtained and the experimental setups used to acquire them. PMID:25866665

  3. Functional materials analysis using in situ and in operando X-ray and neutron scattering

    PubMed Central

    Peterson, Vanessa K.; Papadakis, Christine M.

    2015-01-01

    In situ and in operando studies are commonplace and necessary in functional materials research. This review highlights recent developments in the analysis of functional materials using state-of-the-art in situ and in operando X-ray and neutron scattering and analysis. Examples are given covering a number of important materials areas, alongside a description of the types of information that can be obtained and the experimental setups used to acquire them. PMID:25866665

  4. Gas cell for in situ soft X-ray transmission-absorption spectroscopy of materials

    SciTech Connect

    Drisdell, W. S.; Kortright, J. B.

    2014-07-15

    A simple gas cell design, constructed primarily from commercially available components, enables in situ soft X-ray transmission-absorption spectroscopy of materials in contact with gas at ambient temperature. The cell has a minimum X-ray path length of 1 mm and can hold gas pressures up to ∼300 Torr, and could support higher pressures with simple modifications. The design enables cycling between vacuum and gas environments without interrupting the X-ray beam, and can be fully sealed to allow for measurements of air-sensitive samples. The cell can attach to the downstream port of any appropriate synchrotron beamline, and offers a robust and versatile method for in situ measurements of certain materials. The construction and operation of the cell are discussed, as well as sample preparation and proper spectral analysis, illustrated by examples of spectral measurements. Potential areas for improvement and modification for specialized applications are also mentioned.

  5. Nitride-MBE system for in situ synchrotron X-ray measurements

    NASA Astrophysics Data System (ADS)

    Sasaki, Takuo; Ishikawa, Fumitaro; Yamaguchi, Tomohiro; Takahasi, Masamitu

    2016-05-01

    A molecular beam epitaxy (MBE) chamber dedicated to nitride growth was developed at the synchrotron radiation facility SPring-8. This chamber has two beryllium windows for incident and outgoing X-rays, and is directly connected to an X-ray diffractometer, enabling in situ synchrotron X-ray measurements during the nitride growth. Experimental results on initial growth dynamics in GaN/SiC, AlN/SiC, and InN/GaN heteroepitaxy were presented. We achieved high-speed and high-sensitivity reciprocal space mapping with a thickness resolution of atomic-layer scale. This in situ measurement using the high-brilliance synchrotron light source will be useful for evaluating structural variations in the initial growth stage of nitride semiconductors.

  6. A furnace and environmental cell for the in situ investigation of molten salt electrolysis using high-energy X-ray diffraction.

    PubMed

    Styles, Mark J; Rowles, Matthew R; Madsen, Ian C; McGregor, Katherine; Urban, Andrew J; Snook, Graeme A; Scarlett, Nicola V Y; Riley, Daniel P

    2012-01-01

    This paper describes the design, construction and implementation of a relatively large controlled-atmosphere cell and furnace arrangement. The purpose of this equipment is to facilitate the in situ characterization of materials used in molten salt electrowinning cells, using high-energy X-ray scattering techniques such as synchrotron-based energy-dispersive X-ray diffraction. The applicability of this equipment is demonstrated by quantitative measurements of the phase composition of a model inert anode material, which were taken during an in situ study of an operational Fray-Farthing-Chen Cambridge electrowinning cell, featuring molten CaCl(2) as the electrolyte. The feasibility of adapting the cell design to investigate materials in other high-temperature environments is also discussed. PMID:22186642

  7. In-situ Measurements of Colloid Transport and Retention Using Synchroton X-ray Fluorescence

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The physics regarding the retention and mobilization of colloids in saturated and unsaturated conditions remains poorly understood, partially due to the inability to measure colloid concentrations in-situ. In this study, we attached Cd+2 ions to clay colloids, and used synchrotron x-rays to cause th...

  8. Characterization of the interfacial geomechanics in gas shales via integrated Raman spectroscopy, nanoindentation and energy dispersive X-ray spectroscopy

    NASA Astrophysics Data System (ADS)

    Ferralis, N.; Abedi, S.; Grossman, J. C.; Ulm, F.

    2012-12-01

    The geomechanical characterization of gas shales at the microscale is currently enabled by the use of grid-based nanoindentation techniques. However, the inability to probe the chemical and mineral heterogeneity of gas shales limits the identification of the geomechanical properties of individual components and phases within the probed region. The development of an integrated multiphysics approach that combines geomechanical and chemical information is crucial for the characterization of interfaces between phases, leading to the identification of regions with low yield strain. Here we present a comprehensive investigation where a spatially aligned coupled multiphysics analysis of gas shales is used to identify relevant the geomechanics of mineral and organic phases and their interfaces. This method uses grid-based nanondentation to extract the geomechanical information. Raman spectroscopy is used to identify the majority of inorganic components (calcite, quartz, anatase, pyrite, clay) as well as to characterize the diversity and maturity in the organic component (kerogen). Energy dispersive X-ray is used in combination with Raman to identify clay. With the use of clustering analysis statistical tools a correlation analysis over the full range of data (geomechanics and chemical data), we identify several mineral phases, and we clearly associate the mechanical properties (defined in terms of hardness, modulus and yield strain) with each phase. With this innovative multiphysics analysis we were able to identify interfacial phases between inorganic phases, with distinct hardness and yield strain. We find that regions between calcite-rich or quartz rich phases and clay-rich phases showed a lower than of that of the corresponding boundary phases. Hence this approach provides a viable method for the identification of the "weakest links" in gas shales with the highest probability of fracture.

  9. Gunshot residue testing in suicides: Part I: Analysis by scanning electron microscopy with energy-dispersive X-ray.

    PubMed

    Molina, D Kimberley; Martinez, Michael; Garcia, James; DiMaio, Vincent J M

    2007-09-01

    Several different methods can be employed to test for gunshot residue (GSR) on a deceased person's hands, including scanning electron microscopy with energy-dispersive x-ray spectroscopy (SEM-EDX) and inductively coupled plasma-atomic emission spectrometry (ICP-AES). Each of these techniques has been extensively studied, especially on living individuals. The current studies (Part I and Part II) were designed to compare the use and utility of the different GSR testing techniques in a medical examiner setting. In Part I, the hands of deceased persons who died from undisputed suicidal handgun wounds were tested for GSR by SEM-EDX over a 4-year period. A total of 116 cases were studied and analyzed for caliber of weapon, proximity of wound, and results of GSR testing, including spatial deposition upon the hands. It was found that in only 50% of cases with a known self-inflicted gunshot wound was SEM-EDX positive for at least 1 specific particle for GSR. In 18% of the cases there was a discernible pattern (spatial distribution) of the particles on the hand such that the manner in which the weapon was held could be determined. Since only 50% of cases where the person is known to have fired a weapon immediately prior to death were positive for GSR by SEM-EDX, this test should not be relied upon to determine whether a deceased individual has discharged a firearm. Furthermore, in only 18% of cases was a discernible pattern present indicating how the firearm was held. The low sensitivity, along with the low percentage of cases with a discernible pattern, limits the usefulness of GSR test results by SEM-EDX in differentiating self-inflicted from non-self-inflicted wounds. PMID:17721163

  10. Matrix effects in the energy dispersive X-ray analysis of CaO-Al(2)O(3)-MgO inclusions in steel.

    PubMed

    Pistorius, Petrus Christiaan; Verma, Neerav

    2011-12-01

    Energy dispersive X-ray microanalysis of micron-sized inclusions in steel is of considerable industrial importance. Measured spectra and Monte Carlo simulations show a significant effect of the steel matrix on analysis of CaO-Al(2)O(3)-MgO inclusions: the steel matrix filters the softer (Al and Mg) characteristic X-rays, increasing the relative height of the Ca peak. Bulk matrix correction methods would not result in correct inclusion compositions, but operating at a lower acceleration voltage shifts the effect to smaller inclusion sizes. PMID:22051086

  11. Note: Sample chamber for in situ x-ray absorption spectroscopy studies of battery materials

    SciTech Connect

    Pelliccione, CJ; Timofeeva, EV; Katsoudas, JP; Segre, CU

    2014-12-01

    In situ x-ray absorption spectroscopy (XAS) provides element-specific characterization of both crystalline and amorphous phases and enables direct correlations between electrochemical performance and structural characteristics of cathode and anode materials. In situ XAS measurements are very demanding to the design of the experimental setup. We have developed a sample chamber that provides electrical connectivity and inert atmosphere for operating electrochemical cells and also accounts for x-ray interactions with the chamber and cell materials. The design of the sample chamber for in situ measurements is presented along with example XAS spectra from anode materials in operating pouch cells at the Zn and Sn K-edges measured in fluorescence and transmission modes, respectively. (C) 2014 AIP Publishing LLC.

  12. Facility for combined in situ magnetron sputtering and soft x-ray magnetic circular dichroism

    SciTech Connect

    Telling, N. D.; Laan, G. van der; Georgieva, M. T.; Farley, N. R. S.

    2006-07-15

    An ultrahigh vacuum chamber that enables the in situ growth of thin films and multilayers by magnetron sputtering techniques is described. Following film preparation, x-ray absorption spectroscopy (XAS) and x-ray magnetic circular dichroism (XMCD) measurements are performed by utilizing an in vacuum electromagnet. XMCD measurements on sputtered thin films of Fe and Co yield spin and orbital moments that are consistent with those obtained previously on films measured in transmission geometry and grown in situ by evaporation methods. Thin films of FeN prepared by reactive sputtering are also examined and reveal an apparent enhancement in the orbital moment for low N content samples. The advantages of producing samples for in situ XAS and XMCD studies by magnetron sputtering are discussed.

  13. In situ x-ray, electrochemical, and modeling investigation of the oxygen electrode activation.

    SciTech Connect

    Yildiz, B.; Chang, K.-C.; Meyers, D.; Carter, J. D.; You, H.

    2006-01-01

    Oxygen electrodes of solid oxide electrochemical cells have been shown to improve under strong cathodic and anodic polarization. Our study investigates the mechanism causing such improvement, using in situ x-ray and electrochemical characterization and electrochemical impedance modeling of the oxygen electrodes. Several porous and dense thin-film model electrodes of La{sub 0.8}Sr{sub 0.2}MnO{sub 3} (LSM) and La{sub 0.8}Sr{sub 0.2}MnO{sub 3} (LCM) on single crystal yttria-stabilized zirconia (YSZ) electrolytes have been analyzed in situ at the Advanced Photon Source (APS) using x-ray reflectivity and x-ray absorption near edge spectroscopy (XANES) at the Mn K-edge and La LII-edge. In situ x-ray reflectivity analysis show that no clear correlation between the polarization of the electrode and any further changes in the roughness of the LSM/YSZ interface exist. XANES measurements illustrate that the cathodic or anodic dc polarization at high temperature induces no detectable changes in Mn chemical state either in the bulk or at the surface of the LCM and LSM electrodes on YSZ, while the La chemical state changes reversibly at the electrode surface. This field-induced chemical change of La at the surface of electrodes is assumed to be a cause of the electrochemical activation through enhanced surface exchange of oxygen on the doped lanthanum manganite electrodes.

  14. Energy dispersive X-ray fluorescence analysis of ancient coins: The case of Greek silver drachmae from the Emporion site in Spain

    NASA Astrophysics Data System (ADS)

    Pitarch, A.; Queralt, I.

    2010-05-01

    Greek colonizers arrived at the Iberian Peninsula at the beginning of the sixth century B.C. and founded a small colony known as Emporion in north-east Spain. By the fifth century B.C., this colony became a small polis with a well-organized administrative structure. In this context, the necessity of coinage was a fact and the first coins were minted [1]. Some of these coins were characterized by using energy dispersive X-ray fluorescence equipment. The analytical study focused on the elemental characterization of the coins minted from the fourth century to the first century B.C. and their compositional evolution during this period. The investigation has pointed out a very high fineness of the alloys throughout the time, with an average silver content around 98.32%, and the feasibility of energy dispersive X-ray fluorescence as a screening tool for the characterization of the alloys.

  15. In situ observation of cellular organelles with a contact x-ray microscope

    NASA Astrophysics Data System (ADS)

    Kado, M.; Kishimoto, M.; Tamotsu, S.; Yasuda, K.; Shinohara, K.

    2013-10-01

    A contact x-ray microscope coupled with a highly intense laser plasma soft x-ray source has been developed and in situ observations of cellular organelles have been conducted. The soft x-rays were generated by irradiating a high power laser pulse onto a thin-foiled gold target and about 1.3×1015 photons/sr were obtained, which allowed the inner structures of live wet biological cells to be imaged. Single shot flash imaging is a key technique to image cellular organelles of live biological cells avoiding degradation of the spatial resolution of the images resulting from motion blur and radiation damage. The use of a fluorescence microscope to identify cellular organelles in conjunction with the soft x-ray microscope has allowed several cellular organelles to be identified precisely in the soft x-ray images. Combining the fluorescence microscope with the soft x-ray microscope will be very useful and will establish the technique as a powerful tool to analyze living function of biological cells.

  16. In Situ Synchrotron X-Ray Techniques for the Study of Lithium Battery Materials

    SciTech Connect

    McBreen, J.; Mukerjee, S.; Yang, X. Q.; Sun, X., Ein-Eli, Y.

    1998-11-01

    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 transition metal oxides. Because of its element specific nature XAS can identify the occurrence of redox processes on the various cations in doped oxide cathode materials. Since XAS probes short range order and is particularly useful in the study of amorphous tin based composite oxide anode materials.

  17. Amalgam tattoo: report of an unusual clinical presentation and the use of energy dispersive X-ray analysis as an aid to diagnosis

    SciTech Connect

    McGinnis, J.P. Jr.; Greer, J.L.; Daniels, D.S.

    1985-01-01

    An unusual appearing gingival amalgam pigmentation (amalgam tattoo) that completely surrounded the maxillary right first premolar in a 13-year-old boy is presented. Because of the wide distribution and apparent clinical progression of the discoloration, an excisional biopsy was performed. The histopathologic diagnosis of amalgam pigmentation was confirmed in paraffin sections by energy dispersive X-ray microanalysis. Silver, tin, and mercury were detected in the specimen.

  18. Energy-dispersive X-ray emission spectroscopy using an X-ray free-electron laser in a shot-by-shot mode

    PubMed Central

    Alonso-Mori, Roberto; Kern, Jan; Gildea, Richard J.; Sokaras, Dimosthenis; Weng, Tsu-Chien; Lassalle-Kaiser, Benedikt; Tran, Rosalie; Hattne, Johan; Laksmono, Hartawan; Hellmich, Julia; Glöckner, Carina; Echols, Nathaniel; Sierra, Raymond G.; Schafer, Donald W.; Sellberg, Jonas; Kenney, Christopher; Herbst, Ryan; Pines, Jack; Hart, Philip; Herrmann, Sven; Grosse-Kunstleve, Ralf W.; Latimer, Matthew J.; Fry, Alan R.; Messerschmidt, Marc M.; Miahnahri, Alan; Seibert, M. Marvin; Zwart, Petrus H.; White, William E.; Adams, Paul D.; Bogan, Michael J.; Boutet, Sébastien; Williams, Garth J.; Zouni, Athina; Messinger, Johannes; Glatzel, Pieter; Sauter, Nicholas K.; Yachandra, Vittal K.; Yano, Junko; Bergmann, Uwe

    2012-01-01

    The ultrabright femtosecond X-ray pulses provided by X-ray free-electron lasers open capabilities for studying the structure and dynamics of a wide variety of systems beyond what is possible with synchrotron sources. Recently, this “probe-before-destroy” approach has been demonstrated for atomic structure determination by serial X-ray diffraction of microcrystals. There has been the question whether a similar approach can be extended to probe the local electronic structure by X-ray spectroscopy. To address this, we have carried out femtosecond X-ray emission spectroscopy (XES) at the Linac Coherent Light Source using redox-active Mn complexes. XES probes the charge and spin states as well as the ligand environment, critical for understanding the functional role of redox-active metal sites. Kβ1,3 XES spectra of MnII and Mn2III,IV complexes at room temperature were collected using a wavelength dispersive spectrometer and femtosecond X-ray pulses with an individual dose of up to >100 MGy. The spectra were found in agreement with undamaged spectra collected at low dose using synchrotron radiation. Our results demonstrate that the intact electronic structure of redox active transition metal compounds in different oxidation states can be characterized with this shot-by-shot method. This opens the door for studying the chemical dynamics of metal catalytic sites by following reactions under functional conditions. The technique can be combined with X-ray diffraction to simultaneously obtain the geometric structure of the overall protein and the local chemistry of active metal sites and is expected to prove valuable for understanding the mechanism of important metalloproteins, such as photosystem II. PMID:23129631

  19. In Situ X-Ray Probing Reveals Fingerprints of Surface Platinum Oxide

    SciTech Connect

    Friebel, Daniel

    2011-08-24

    In situ x-ray absorption spectroscopy (XAS) at the Pt L{sub 3} edge is a useful probe for Pt-O interactions at polymer electrolyte membrane fuel cell (PEMFC) cathodes. We show that XAS using the high energy resolution fluorescence detection (HERFD) mode, applied to a well-defined monolayer Pt/Rh(111) sample where the bulk penetrating hard x-rays probe only surface Pt atoms, provides a unique sensitivity to structure and chemical bonding at the Pt-electrolyte interface. Ab initio multiple-scattering calculations using the FEFF8 code and complementary extended x-ray absorption fine structure (EXAFS) results indicate that the commonly observed large increase of the white-line at high electrochemical potentials on PEMFC cathodes originates from platinum oxide formation, whereas previously proposed chemisorbed oxygen-containing species merely give rise to subtle spectral changes.

  20. In situ X-ray snapshot analysis of transient molecular adsorption in a crystalline channel

    NASA Astrophysics Data System (ADS)

    Kubota, Ryou; Tashiro, Shohei; Shiro, Motoo; Shionoya, Mitsuhiko

    2014-10-01

    Molecular adsorption is a fundamental phenomenon in porous materials and is usually characterized by the efficiency and selectivity of molecular separations and reactions. However, for functional porous materials, analysis of the dynamic behaviour of molecular adsorbents is a major challenge. Here, we use in situ single-crystal X-ray diffraction to analyse multi-step molecular adsorption in a crystalline nanochannel of a metal-macrocycle framework. The pore surface of the metal-macrocycle framework crystal contains five different enantiomerically paired binding pockets, to which the adsorption of a (1R)-1-(3-chlorophenyl)ethanol solution was monitored with time. The resulting X-ray snapshot analyses suggest that the guest adsorption process takes a two-step pathway before equilibrium, in which the guest molecule is temporarily trapped by a neighbouring binding site. This demonstrates the potential for using X-ray analyses to visualize a transient state during a non-covalent self-assembly process.

  1. In situ laser heating and radial synchrotron X-ray diffraction ina diamond anvil cell

    SciTech Connect

    Kunz, Martin; Caldwell, Wendel A.; Miyagi, Lowell; Wenk,Hans-Rudolf

    2007-06-29

    We report a first combination of diamond anvil cell radialx-ray diffraction with in situ laser heating. The laser-heating setup ofALS beamline 12.2.2 was modified to allow one-sided heating of a samplein a diamond anvil cell with an 80 W yttrium lithium fluoride laser whileprobing the sample with radial x-ray diffraction. The diamond anvil cellis placed with its compressional axis vertical, and perpendicular to thebeam. The laser beam is focused onto the sample from the top while thesample is probed with hard x-rays through an x-ray transparentboron-epoxy gasket. The temperature response of preferred orientation of(Fe,Mg)O is probed as a test experiment. Recrystallization was observedabove 1500 K, accompanied by a decrease in stress.

  2. Investigation of x-ray photon counting using a silicon-PIN diode and its application to energy-dispersive computed tomography

    NASA Astrophysics Data System (ADS)

    Kodama, Hajime; Sato, Eiichi; Sagae, Michiaki; Hagiwara, Osahiko; Matsukiyo, Hiroshi; Osawa, Akihiro; Enomoto, Toshiyuki; Watanabe, Manabu; Kusachi, Shinya; Sato, Shigehiro; Ogawa, Akira

    2013-09-01

    X-ray photon counting was performed using a readymade silicon-PIN photodiode (Si-PIN-PD) at tube voltages ranging from 42 to 60 kV, and X-ray photons are directly detected using the 100 MHz Si-PIN-PD without a scintillator. Photocurrent from the diode is amplified using charge-sensitive and shaping amplifiers. Using a multichannel analyzer, X-ray spectra at a tube voltage of 60 kV could easily be measured. The photon-counting computed tomography (PCCT) is accomplished by repeated linear scans and rotations of an object, and projection curves of the object are obtained by the linear scan. In the PC-CT, we confirmed the energy-dispersive effect with changes in lower-level voltage of the event pulse using a comparator.

  3. Cyclic olefin homopolymer-based microfluidics for protein crystallization and in situ X-ray diffraction

    SciTech Connect

    Emamzadah, Soheila; Petty, Tom J.; De Almeida, Victor; Nishimura, Taisuke; Joly, Jacques; Ferrer, Jean-Luc; Halazonetis, Thanos D.

    2009-09-01

    A cyclic olefin homopolymer-based microfluidics system has been established for protein crystallization and in situ X-ray diffraction. Microfluidics is a promising technology for the rapid identification of protein crystallization conditions. However, most of the existing systems utilize silicone elastomers as the chip material which, despite its many benefits, is highly permeable to water vapour. This limits the time available for protein crystallization to less than a week. Here, the use of a cyclic olefin homopolymer-based microfluidics system for protein crystallization and in situ X-ray diffraction is described. Liquid handling in this system is performed in 2 mm thin transparent cards which contain 500 chambers, each with a volume of 320 nl. Microbatch, vapour-diffusion and free-interface diffusion protocols for protein crystallization were implemented and crystals were obtained of a number of proteins, including chicken lysozyme, bovine trypsin, a human p53 protein containing both the DNA-binding and oligomerization domains bound to DNA and a functionally important domain of Arabidopsis Morpheus’ molecule 1 (MOM1). The latter two polypeptides have not been crystallized previously. For X-ray diffraction analysis, either the cards were opened to allow mounting of the crystals on loops or the crystals were exposed to X-rays in situ. For lysozyme, an entire X-ray diffraction data set at 1.5 Å resolution was collected without removing the crystal from the card. Thus, cyclic olefin homopolymer-based microfluidics systems have the potential to further automate protein crystallization and structural genomics efforts.

  4. In situ surface/interface x-ray diffractometer for oxide molecular beam epitaxy

    SciTech Connect

    Lee, J. H.; Tung, I. C.; Chang, S. -H.; Bhattacharya, A.; Fong, D. D.; Freeland, J. W.; Hong, Hawoong

    2016-01-01

    In situ studies of oxide molecular beam epitaxy by synchrotron x-ray scattering has been made possible by upgrading an existing UHV/molecular beam epitaxy (MBE) six-circle diffractometer system. For oxide MBE growth, pure ozone delivery to the chamber has been made available, and several new deposition sources have been made available on a new 12 in. CF (ConFlat, a registered trademark of Varian, Inc.) flange. X-ray diffraction has been used as a major probe for film growth and structures for the system. In the original design, electron diffraction was intended for the secondary diagnostics available without the necessity of the x-ray and located at separate positions. Deposition of films was made possible at the two diagnostic positions. And, the aiming of the evaporation sources is fixed to the point between two locations. Ozone can be supplied through two separate nozzles for each location. Also two separate thickness monitors are installed. Additional features of the equipment are also presented together with the data taken during typical oxide film growth to illustrate the depth of information available via in situ x-ray techniques.

  5. In situ surface/interface x-ray diffractometer for oxide molecular beam epitaxy.

    PubMed

    Lee, J H; Tung, I C; Chang, S-H; Bhattacharya, A; Fong, D D; Freeland, J W; Hong, Hawoong

    2016-01-01

    In situ studies of oxide molecular beam epitaxy by synchrotron x-ray scattering has been made possible by upgrading an existing UHV/molecular beam epitaxy (MBE) six-circle diffractometer system. For oxide MBE growth, pure ozone delivery to the chamber has been made available, and several new deposition sources have been made available on a new 12 in. CF (ConFlat, a registered trademark of Varian, Inc.) flange. X-ray diffraction has been used as a major probe for film growth and structures for the system. In the original design, electron diffraction was intended for the secondary diagnostics available without the necessity of the x-ray and located at separate positions. Deposition of films was made possible at the two diagnostic positions. And, the aiming of the evaporation sources is fixed to the point between two locations. Ozone can be supplied through two separate nozzles for each location. Also two separate thickness monitors are installed. Additional features of the equipment are also presented together with the data taken during typical oxide film growth to illustrate the depth of information available via in situ x-ray techniques. PMID:26827327

  6. Two-dimensional in situ metrology of X-ray mirrors using the speckle scanning technique.

    PubMed

    Wang, Hongchang; Kashyap, Yogesh; Laundy, David; Sawhney, Kawal

    2015-07-01

    In situ metrology overcomes many of the limitations of existing metrology techniques and is capable of exceeding the performance of present-day optics. A novel technique for precisely characterizing an X-ray bimorph mirror and deducing its two-dimensional (2D) slope error map is presented. This technique has also been used to perform fast optimization of a bimorph mirror using the derived 2D piezo response functions. The measured focused beam size was significantly reduced after the optimization, and the slope error map was then verified by using geometrical optics to simulate the focused beam profile. This proposed technique is expected to be valuable for in situ metrology of X-ray mirrors at synchrotron radiation facilities and in astronomical telescopes. PMID:26134795

  7. Electrochemical flowcell for in-situ investigations by soft x-ray absorption and emission spectroscopy

    SciTech Connect

    Schwanke, C.; Lange, K. M.; Golnak, R.; Xiao, J.

    2014-10-15

    A new liquid flow-cell designed for electronic structure investigations at the liquid-solid interface by soft X-ray absorption and emission spectroscopy is presented. A thin membrane serves simultaneously as a substrate for the working electrode and solid state samples as well as for separating the liquid from the surrounding vacuum conditions. In combination with counter and reference electrodes this approach allows in-situ studies of electrochemical deposition processes and catalytic reactions at the liquid-solid interface in combination with potentiostatic measurements. As model system in-situ monitoring of the deposition process of Co metal from a 10 mM CoCl{sub 2} aqueous solution by X-ray absorption and emission spectroscopy is presented.

  8. In situ x-ray investigation of freestanding nanoscale Cu-Nb multilayers under tensile load.

    SciTech Connect

    Aydiner, C. C.; Misra, A.; Brown, D. W.; Mara, N. A.; Almer, J. D

    2009-01-01

    The yield behavior in a freestanding sputter-deposited Cu/Nb multilayer with 30 nm nominal individual layer thickness has been investigated with in situ synchrotron x-ray diffraction during tensile loading. A pronounced elastic-plastic transition is observed with the fraction of plastically yielded grains increasing gradually with strain. Near synchronous yielding is observed in the Cu and Nb grains. The gradual progression in yield behavior is interpreted in terms of residual stresses, and elastic and plastic anisotropy.

  9. Development of in situ, at-wavelength metrology for soft x-ray nano-focusing

    SciTech Connect

    Yuan, Sheng Sam; Yashchuk, Valeriy V.; Goldberg, Kenneth A.; Celestre, Richard; McKinney, Wayne R.; Morrison, Gregory Y.; Warwick, Tony; Padmore, Howard A.

    2010-09-19

    At the Advanced Light Source (ALS), we are developing broadly applicable, high-accuracy, in situ, at-wavelength wavefront slope measurement techniques for Kirkpatrick-Baez (KB) mirror nano-focusing. We describe here details of the metrology beamline endstation, the at-wavelength tests, and an original alignment method that have already allowed us to precisely set a bendable KB mirror to achieve a FWHM focused spot size of ~;;120 nm, at 1-nm soft x-ray wavelength.

  10. In-situ synchrotron x-ray transmission microscopy of the sintering of multilayers

    NASA Astrophysics Data System (ADS)

    Yan, Zilin; Guillon, Olivier; Martin, Christophe L.; Wang, Steve; Lee, Chul-Seung; Bouvard, Didier

    2013-06-01

    This letter reports on in-situ characterization of the high temperature sintering of multilayer ceramic capacitors by high-resolution synchrotron x-ray imaging. Microstructural evolution was obtained in real time by a continuous recording of 2-dimensional radiographs. Anisotropic strains were measured for different layers. Quantification of defects was conducted with 3-dimensional nano-computed tomography. These in-situ observations prove that electrode discontinuities occur at the early stage of sintering and originate from initial heterogeneities linked to the particulate nature of the starting powders.

  11. In Situ Soft X-ray Spectroscopy Characterization of Interfacial Phenomena in Energy Materials and Devices

    NASA Astrophysics Data System (ADS)

    Guo, Jinghua; Liu, Yi-Sheng; Kapilashrami, Mukes; Glans, Per-Anders; Bora, Debajeet; Braun, Artur; Velasco Vélez, Juan Jesús; Salmeron, Miquel; ALS/LBNL Team; EMPA, MSD/LBNL Collaboration

    2015-03-01

    Advanced energy technology arises from the understanding in basic science, thus rest in large on in-situ/operando characterization tools for observing the physical and chemical interfacial processes, which has been largely limited in a framework of thermodynamic and kinetic concepts or atomic and nanoscale. In many important energy systems such as energy conversion, energy storage and catalysis, advanced materials and functionality in devices are based on the complexity of material architecture, chemistry and interactions among constituents within. To understand and thus ultimately control the energy conversion and energy storage applications calls for in-situ/operando characterization tools. Soft X-ray spectroscopy offers a number of very unique features. We will present our development of the in-situ/operando soft X-ray spectroscopic tools of catalytic and electrochemical reactions in recent years, and reveal how to overcome the challenge that soft X-rays cannot easily peek into the high-pressure catalytic cells or liquid electrochemical cells. In this presentation a number of examples are given, including the nanocatalysts and the recent experiment performed for studying the hole generation in a specifically designed photoelectrochemical cell under operando conditions. The ALS is supported by the the U.S. Department of Energy.

  12. THIN-FILM DENSITY DETERMINATION OF TANTALUM, TANTALUM OXIDES, AND XEROGELS BY MULTIPLE RADIATION ENERGY DISPERSIVE X-RAY REFLECTIVITY

    EPA Science Inventory

    X-ray reflectivity provides a nondestructive technique for measuring density in thin films. A conventional laboratory, Bragg-Brentano geometry diffractometer was employed to show the generalized feasibility of this technique. X-ray tubes with chromium, copper, and molybdenum targ...

  13. X-ray energy dispersive spectroscopy of uranium ore using a TES microcalorimeter mounted on a field-emission scanning electron microscope

    NASA Astrophysics Data System (ADS)

    Maehata, Keisuke; Idemitsu, Kazuya; Tanaka, Keiichi

    2011-08-01

    Energy dispersive spectroscopic measurements of uranium ore were conducted using a superconducting phase transition-edge-thermosensor (TES) microcalorimeter mounted on a field-emission scanning electron microscope (SEM) to demonstrate its potential for high-precision microanalysis. The effective solid angle for X-ray detection is found to be larger than 2 msr by precise adjustments in the X-ray polycapillary alignment. The observed detection signal pulses with decay time constant of 50 μs enable maximum count rates larger than 300 counts per second. The energy resolution was determined to be 14.6 eV FWHM at Al Kα X-ray energies of 1487 eV. Distinct peaks appear in the resulting X-ra y energy spectrum associated with U-Mα, U-Mβ and U-Mγ X-rays emitted by the uranium ore specimens. This spectrum includes weaker peaks corresponding to C-Kα, Fe-Lα, Cu-L and Sr L α1 X rays.

  14. Determination of trace elements in Syrian medicinal plants and their infusions by energy dispersive X-ray fluorescence and total reflection X-ray fluorescence spectrometry

    NASA Astrophysics Data System (ADS)

    Khuder, A.; Sawan, M. Kh.; Karjou, J.; Razouk, A. K.

    2009-07-01

    X-ray fluorescence (XRF) and total-reflection X-ray fluorescence (TXRF) techniques suited well for a multi-element determination of K, Ca, Mn, Fe, Cu, Zn, Rb, and Sr in some Syrian medicinal plant species. The accuracy and the precision of both techniques were verified by analyzing the Standard Reference Materials (SRM) peach-1547 and apple leaves-1515. A good agreement between the measured concentrations of the previously mentioned elements and the certified values were obtained with errors less than 10.7% for TXRF and 15.8% for XRF. The determination of Br was acceptable only by XRF with an error less than 24%. Furthermore, the XRF method showed a very good applicability for the determination of K, Ca, Mn, Fe, Cu, Zn, Rb, Sr, and Br in infusions of different Syrian medicinal plant species, namely anise ( Anisum vulgare), licorice root ( Glycyrrhiza glabra), and white wormwood ( Artemisia herba-alba).

  15. Electron-excited energy dispersive X-ray spectrometry at high speed and at high resolution: silicon drift detectors and microcalorimeters.

    PubMed

    Newbury, Dale E

    2006-12-01

    Two recent developments in X-ray spectrometer technology provide dramatic improvements in analytical capabilities that impact the frontiers of electron microscopy. Silicon drift detectors (SDD) use the same physics as silicon (lithium) energy dispersive spectrometers [Si(Li) EDS] but differ in design: only 10% of the thickness of the Si(Li) EDS with an anode area below 0.1 mm2 and a complex rear surface electrode pattern that creates a lateral internal charge collection field. The SDD equals or betters the Si(Li) EDS in most measures of performance. For output versus input count rate, the SDD exceeds the Si(Li) EDS by a factor of 5 to 10 for the same resolution. This high throughput can benefit analytical measurements that are count limited, such as X-ray mapping and trace measurements. The microcalorimeter EDS determines the X-ray energy by measuring the temperature rise in a metal absorber. Operating at 100 mK, the microcalorimeter EDS achieves resolution of 2-5 eV over a photon energy range of 200 eV to 10 keV in energy dispersive operation, eliminating most peak interference situations and providing high peak-to-background to detect low fluorescence yield peaks. Chemical bonding effects on low energy (< 2 keV) peak shapes can be measured. PMID:19830945

  16. In situ x-ray diffraction measurements of the capillary fountain jet produced via ultrasonic atomization

    NASA Astrophysics Data System (ADS)

    Yano, Yohko F.; Douguchi, Junya; Kumagai, Atsushi; Iijima, Takao; Tomida, Yukinobu; Miyamoto, Toshiaki; Matsuura, Kazuo

    2006-11-01

    In situ x-ray diffraction measurements were carried out for investigating the liquid structure in the ultrasonic fountain jet to consider the mechanism of the "ultrasonic ethanol separation" reported by Sato et al. [J. Chem. Phys. 114, 2382 (2001)]. For pure liquids (water and ethanol), it was found that the high frequency ultrasound does not affect the liquid structure microscopically. For the 20mol% ethanol-water mixture, the estimated ethanol mole fraction in the ultrasonic fountain jet by using the position of the main maximum in the x-ray diffraction profile coincided with that in the reservoir. This result suggests that the ethanol separation is not caused by any distorted liquid structure under the ultrasound irradiation and occurs when or after the generation of the liquid droplet mist.

  17. In situ x-ray diffraction measurements of the capillary fountain jet produced via ultrasonic atomization.

    PubMed

    Yano, Yohko F; Douguchi, Junya; Kumagai, Atsushi; Iijima, Takao; Tomida, Yukinobu; Miyamoto, Toshiaki; Matsuura, Kazuo

    2006-11-01

    In situ x-ray diffraction measurements were carried out for investigating the liquid structure in the ultrasonic fountain jet to consider the mechanism of the "ultrasonic ethanol separation" reported by Sato et al. [J. Chem. Phys. 114, 2382 (2001)]. For pure liquids (water and ethanol), it was found that the high frequency ultrasound does not affect the liquid structure microscopically. For the 20 mol % ethanol-water mixture, the estimated ethanol mole fraction in the ultrasonic fountain jet by using the position of the main maximum in the x-ray diffraction profile coincided with that in the reservoir. This result suggests that the ethanol separation is not caused by any distorted liquid structure under the ultrasound irradiation and occurs when or after the generation of the liquid droplet mist. PMID:17100459

  18. Instrument for x-ray absorption spectroscopy with in situ electrical control characterizations

    SciTech Connect

    Huang, Chun-Chao; Chang, Shu-Jui; Yang, Chao-Yao; Tseng, Yuan-Chieh; Chou, Hsiung

    2013-12-15

    We report a synchrotron-based setup capable of performing x-ray absorption spectroscopy and x-ray magnetic circular dichroism with simultaneous electrical control characterizations. The setup can enable research concerning electrical transport, element- and orbital-selective magnetization with an in situ fashion. It is a unique approach to the real-time change of spin-polarized electronic state of a material/device exhibiting magneto-electric responses. The performance of the setup was tested by probing the spin-polarized states of cobalt and oxygen of Zn{sub 1-x}Co{sub x}O dilute magnetic semiconductor under applied voltages, both at low (∼20 K) and room temperatures, and signal variations upon the change of applied voltage were clearly detected.

  19. In situ compressive damage of cement paste characterized by lab source X-ray computer tomography

    SciTech Connect

    Wan, Keshu; Xue, Xiaobo

    2013-08-15

    This paper aims at illustrating the potential of lab source X-ray CT for studying the damage behavior of cement based materials through in situ load experiments. This approach permits quantifying the microstructure prior and during loading. The load damage is separated from the specimen deformation using an image interpolation method. A quantitative relationship between external load and internal specimen damage is analyzed using the statistical information of gray scale values of the CT data. Local damage degrees are defined on 3D subset, and the 3D spatial distribution of damage information is clarified in this research. - Highlights: • On line damage is characterized by lab source X-ray CT. • Loading damage is separated with the specimen deformation. • Local damage is analyzed using gray scale values of the CT data. • 3D spatial distribution of the local damage information is clarified.

  20. Rapid in situ X-ray position stabilization via extremum seeking feedback.

    PubMed

    Zohar, S; Venugopalan, N; Kissick, D; Becker, M; Xu, S; Makarov, O; Stepanov, S; Ogata, C; Sanishvili, R; Fischetti, R F

    2016-03-01

    X-ray beam stability is crucial for acquiring high-quality data at synchrotron beamline facilities. When the X-ray beam and defining apertures are of similar dimensions, small misalignments driven by position instabilities give rise to large intensity fluctuations. This problem is solved using extremum seeking feedback control (ESFC) for in situ vertical beam position stabilization. In this setup, the intensity spatial gradient required for ESFC is determined by phase comparison of intensity oscillations downstream from the sample with pre-existing vertical beam oscillations. This approach compensates for vertical position drift from all sources with position recovery times <6 s and intensity stability through a 5 µm aperture measured at 1.5% FWHM over a period of 8 hours. PMID:26917131

  1. In situ x-ray photoelectron spectroscopy for electrochemical reactions in ordinary solvents

    SciTech Connect

    Masuda, Takuya; Yoshikawa, Hideki; Kobata, Masaaki; Kobayashi, Keisuke; Noguchi, Hidenori; Kawasaki, Tadahiro; Uosaki, Kohei

    2013-09-09

    In situ electrochemical X-ray photoelectron spectroscopy (XPS) apparatus, which allows XPS at solid/liquid interfaces under potential control, was constructed utilizing a microcell with an ultra-thin Si membrane, which separates vacuum and a solution. Hard X-rays from a synchrotron source penetrate into the Si membrane surface exposed to the solution. Electrons emitted at the Si/solution interface can pass through the membrane and be analyzed by an analyzer placed in vacuum. Its operation was demonstrated for potential-induced Si oxide growth in water. Effect of potential and time on the thickness of Si and Si oxide layers was quantitatively determined at sub-nanometer resolution.

  2. Solution spectroelectrochemical cell for in situ X-ray absorption fine structure

    SciTech Connect

    Antonio, M.R.; Soderholm, L.; Song, I.

    1995-06-12

    A purpose-built spectroelectrochemical cell for in situ fluorescence XAFS (X-ray Absorption Fine Structure) measurements of bulk solution species during constant-potential electrolysis is described. The cell performance was demonstrated by the collection of europium L{sub 3}-edge XANES (X-ray Absorption Near Edge Structure) throughout the course of electrolysis of an aqueous solution of EuCl{sub 3}{center_dot}6H{sub 2}O in 1 M H{sub 2}SO{sub 4}. The europium L{sub 3}-edge resonances reported here for the Eu{sup III} and Eu{sup II} ions demonstrate that their 2p{sub 3/2} {yields} 5d electronic transition probabilities are not the same.

  3. A correlative approach to segmenting phases and ferrite morphologies in transformation-induced plasticity steel using electron back-scattering diffraction and energy dispersive X-ray spectroscopy.

    PubMed

    Gazder, Azdiar A; Al-Harbi, Fayez; Spanke, Hendrik Th; Mitchell, David R G; Pereloma, Elena V

    2014-12-01

    Using a combination of electron back-scattering diffraction and energy dispersive X-ray spectroscopy data, a segmentation procedure was developed to comprehensively distinguish austenite, martensite, polygonal ferrite, ferrite in granular bainite and bainitic ferrite laths in a thermo-mechanically processed low-Si, high-Al transformation-induced plasticity steel. The efficacy of the ferrite morphologies segmentation procedure was verified by transmission electron microscopy. The variation in carbon content between the ferrite in granular bainite and bainitic ferrite laths was explained on the basis of carbon partitioning during their growth. PMID:25126753

  4. X-ray Photon Counting Using 100 MHz Ready-Made Silicon P-Intrinsic-N X-ray Diode and Its Application to Energy-Dispersive Computed Tomography

    NASA Astrophysics Data System (ADS)

    Kodama, Hajime; Watanabe, Manabu; Sato, Eiichi; Oda, Yasuyuki; Hagiwara, Osahiko; Matsukiyo, Hiroshi; Osawa, Akihiro; Enomoto, Toshiyuki; Kusachi, Shinya; Sato, Shigehiro; Ogawa, Akira

    2013-07-01

    X-ray photons are directly detected using a 100 MHz ready-made silicon P-intrinsic-N X-ray diode (Si-PIN-XD). The Si-PIN-XD is shielded using an aluminum case with a 25-µm-thick aluminum window and a BNC connector. The photocurrent from the Si-PIN-XD is amplified by charge sensitive and shaping amplifiers, and the event pulses are sent to a multichannel analyzer (MCA) to measure X-ray spectra. At a tube voltage of 90 kV, we observe K-series characteristic X-rays of tungsten. Photon-counting computed tomography (PC-CT) is accomplished by repeated linear scans and rotations of an object, and projection curves of the object are obtained by linear scanning at a tube current of 2.0 mA. The exposure time for obtaining a tomogram is 10 min with scan steps of 0.5 mm and rotation steps of 1.0°. At a tube voltage of 90 kV, the maximum count rate is 150 kcps. We carry out PC-CT using gadolinium media and confirm the energy-dispersive effect with changes in the lower level voltage of the event pulse using a comparator.

  5. A new method for polychromatic X-ray μLaue diffraction on a Cu pillar using an energy-dispersive pn-junction charge-coupled device

    SciTech Connect

    Abboud, A.; Send, S.; Pashniak, N.; Pietsch, U.; Kirchlechner, C.; Micha, J. S.; Ulrich, O.; Keckes, J.

    2014-11-15

    μLaue diffraction with a polychromatic X-ray beam can be used to measure strain fields and crystal orientations of micro crystals. The hydrostatic strain tensor can be obtained once the energy profile of the reflections is measured. However, this remains a challenge both on the time scale and reproducibility of the beam position on the sample. In this review, we present a new approach to obtain the spatial and energy profiles of Laue spots by using a pn-junction charge-coupled device, an energy-dispersive area detector providing 3D resolution of incident X-rays. The morphology and energetic structure of various Bragg peaks from a single crystalline Cu micro-cantilever used as a test system were simultaneously acquired. The method facilitates the determination of the Laue spots’ energy spectra without filtering the white X-ray beam. The synchrotron experiment was performed at the BM32 beamline of ESRF using polychromatic X-rays in the energy range between 5 and 25 keV and a beam size of 0.5 μm × 0.5 μm. The feasibility test on the well known system demonstrates the capabilities of the approach and introduces the “3D detector method” as a promising tool for material investigations to separate bending and strain for technical materials.

  6. A new method for polychromatic X-ray μLaue diffraction on a Cu pillar using an energy-dispersive pn-junction charge-coupled device.

    PubMed

    Abboud, A; Kirchlechner, C; Send, S; Micha, J S; Ulrich, O; Pashniak, N; Strüder, L; Keckes, J; Pietsch, U

    2014-11-01

    μLaue diffraction with a polychromatic X-ray beam can be used to measure strain fields and crystal orientations of micro crystals. The hydrostatic strain tensor can be obtained once the energy profile of the reflections is measured. However, this remains a challenge both on the time scale and reproducibility of the beam position on the sample. In this review, we present a new approach to obtain the spatial and energy profiles of Laue spots by using a pn-junction charge-coupled device, an energy-dispersive area detector providing 3D resolution of incident X-rays. The morphology and energetic structure of various Bragg peaks from a single crystalline Cu micro-cantilever used as a test system were simultaneously acquired. The method facilitates the determination of the Laue spots' energy spectra without filtering the white X-ray beam. The synchrotron experiment was performed at the BM32 beamline of ESRF using polychromatic X-rays in the energy range between 5 and 25 keV and a beam size of 0.5 μm × 0.5 μm. The feasibility test on the well known system demonstrates the capabilities of the approach and introduces the "3D detector method" as a promising tool for material investigations to separate bending and strain for technical materials. PMID:25430118

  7. The Analysis of Particles at Low Accelerating Voltages (≤ 10 kV) With Energy Dispersive X-Ray Spectroscopy (EDS)

    PubMed Central

    Small, J. A.

    2002-01-01

    In recent years, there have been a series of advancements in electron beam instruments and x-ray detectors which may make it possible to improve significantly the quality of results from the quantitative electron-probe analysis of individual particles. These advances include: (1) field-emission gun electron beam instruments such as scanning electron microscopes (FEG-SEMs) that have high brightness electron guns with excellent performance at low beam energies, E0 ≤ 10 keV and (2) high-resolution energy-dispersive x-ray spectrometers, like the microcalorimeter detector, that provide high-resolution (< 10 eV) parallel x-ray collection. These devices make it possible to separate low energy (< 4 keV) x-ray lines including the K lines of carbon, nitrogen and oxygen and the L and M lines for elements with atomic numbers in the range of 25 to 83. In light of these advances, this paper investigates the possibility of using accelerating voltages ≤ 10 kV, as a method to improve the accuracy of elemental analysis for micrometer-sized particles.

  8. In situ X-ray monitoring of damage accumulation in SiC/RBSN tensile specimens

    NASA Technical Reports Server (NTRS)

    Baaklini, George Y.; Bhatt, Ramkrishna T.

    1991-01-01

    The room-temperature tensile testing of silicon carbide fiber reinforced reaction-bonded silicon nitride (SiC/RBSN) composite specimens was monitored by using in-situ X-ray film radiography. Radiographic evaluation before, during, and after loading provided data on the effect of preexisting volume flaws (high density impurities, and local density variations) on the fracture behavior of composites. Results from (O)1, (O)3, (O)5, and (O)8 composite specimens showed that X-ray film radiography can monitor damage accumulations during tensile loading. Matrix cracking, fiber-matrix debonding, and fiber pullout were imaged throughout the tensile loading history of the specimens. Further, in-situ film radiography was found to be a helpful and practical technique for estimating interfacial shear strength between the SiC fiber and the RBSN matrix by the matrix crack spacing method. It is concluded that pretest, in-situ, and post-test radiography can provide for a greater understanding of ceramic matrix composite mechanical behavior, a verification of related experimental procedures, and a validation and development of related analytical models.

  9. X-ray microscopy for in situ characterization of 3D nanostructural evolution in the laboratory

    NASA Astrophysics Data System (ADS)

    Hornberger, Benjamin; Bale, Hrishikesh; Merkle, Arno; Feser, Michael; Harris, William; Etchin, Sergey; Leibowitz, Marty; Qiu, Wei; Tkachuk, Andrei; Gu, Allen; Bradley, Robert S.; Lu, Xuekun; Withers, Philip J.; Clarke, Amy; Henderson, Kevin; Cordes, Nikolaus; Patterson, Brian M.

    2015-09-01

    X-ray microscopy (XRM) has emerged as a powerful technique that reveals 3D images and quantitative information of interior structures. XRM executed both in the laboratory and at the synchrotron have demonstrated critical analysis and materials characterization on meso-, micro-, and nanoscales, with spatial resolution down to 50 nm in laboratory systems. The non-destructive nature of X-rays has made the technique widely appealing, with potential for "4D" characterization, delivering 3D micro- and nanostructural information on the same sample as a function of sequential processing or experimental conditions. Understanding volumetric and nanostructural changes, such as solid deformation, pore evolution, and crack propagation are fundamental to understanding how materials form, deform, and perform. We will present recent instrumentation developments in laboratory based XRM including a novel in situ nanomechanical testing stage. These developments bridge the gap between existing in situ stages for micro scale XRM, and SEM/TEM techniques that offer nanometer resolution but are limited to analysis of surfaces or extremely thin samples whose behavior is strongly influenced by surface effects. Several applications will be presented including 3D-characterization and in situ mechanical testing of polymers, metal alloys, composites and biomaterials. They span multiple length scales from the micro- to the nanoscale and different mechanical testing modes such as compression, indentation and tension.

  10. In situ X-ray monitoring of damage accumulation in SiC/RBSN tensile specimens

    SciTech Connect

    Baaklini, G.Y.; Bhatt, R.T.

    1991-08-01

    The room-temperature tensile testing of silicon carbide fiber reinforced reaction-bonded silicon nitride (SiC/RBSN) composite specimens was monitored by using in-situ X-ray film radiography. Radiographic evaluation before, during, and after loading provided data on the effect of preexisting volume flaws (high density impurities, and local density variations) on the fracture behavior of composites. Results from (O)1, (O)3, (O)5, and (O)8 composite specimens showed that X-ray film radiography can monitor damage accumulations during tensile loading. Matrix cracking, fiber-matrix debonding, and fiber pullout were imaged throughout the tensile loading history of the specimens. Further, in-situ film radiography was found to be a helpful and practical technique for estimating interfacial shear strength between the SiC fiber and the RBSN matrix by the matrix crack spacing method. It is concluded that pretest, in-situ, and post-test radiography can provide for a greater understanding of ceramic matrix composite mechanical behavior, a verification of related experimental procedures, and a validation and development of related analytical models. 14 refs.

  11. In situ X-ray pair distribution function analysis of geopolymer gel nanostructure formation kinetics.

    PubMed

    White, Claire E; Provis, John L; Bloomer, Breaunnah; Henson, Neil J; Page, Katharine

    2013-06-14

    With the ever-increasing environmentally-driven demand for technologically advanced structural materials, geopolymer cement is fast becoming a viable alternative to traditional cements due to its proven engineering characteristics and the reduction in CO2 emitted during manufacturing (as much as 80% less CO2 emitted in manufacture, compared to ordinary Portland cement). Nevertheless, much remains unknown regarding the kinetics of reaction responsible for nanostructural evolution during the geopolymerisation process. Here, in situ X-ray total scattering measurements and pair distribution function (PDF) analysis are used to quantify the extent of reaction as a function of time for alkali-activated metakaolin/slag geopolymer binders, including the impact of various activators (alkali hydroxide/silicate) on the kinetics of the geopolymerisation reaction. Quantifying the reaction process in situ from X-ray PDF data collected during the initial ten hours can provide an estimate of the total reaction extent, but when combined with data obtained at longer times (128 days here) enables more accurate determination of the overall rate of reaction. To further assess the initial stages of the geopolymerisation reaction process, a pseudo-single step first order rate equation is fitted to the extent of reaction data, which reveals important mechanistic information regarding the role of free silica in the activators in the evolution of the binder systems. Hence, it is shown that in situ X-ray PDF analysis is an ideal experimental local structure tool to probe the reaction kinetics of complex reacting systems involving transitions between disordered/amorphous phases, of which geopolymerisation is an important example. PMID:23450172

  12. [Energy-dispersive x-ray fluorescence spectrometry--a forensic chemistry method for determination of shooting distance].

    PubMed

    Havel, J

    2003-10-01

    The article follows up the experiences Energo-dispersive X-ray fluorescence spectrometry (EDXRF) as the forensic necrochemical method as the tool for detection of metals (gunshot residues--GSR) in connection with gunshot-wounds of persons--authors: dipl. Ing. J. Havel and dipl. Ing. K. Zelenka and Energo-dispersive X-ray fluorescence spectrometry (EDXRF) as the forensic method as the tool for identification of inlets (gunshot--entries) and outlets (gunshot--exits)--author: dipl. Ing. J. Havel. PMID:14661530

  13. In situ x-ray diffraction of shock-driven deformation and phase transformation in titanium

    NASA Astrophysics Data System (ADS)

    Bolme, Cynthia; Lazicki, Amy; Brown, Don; Gleason, Arianna; Cerreta, Ellen; Morrow, Ben; Ali, Suzanne; Swift, Damian; Nagler, Bob; Galtier, Eric; Granados, Eduardo; Milathianaki, Despina; Heimann, Phil

    2015-06-01

    Titanium alloys are employed in demanding engineering applications due to their high strength-to-weight ratio and their resistance to corrosion. Pure titanium and titanium with high levels of oxygen impurities were studied under laser-driven shock compression at the Matter in Extreme Conditions endstation at the Linac Coherent Light Source. In situ x-ray diffraction data were acquired during compression, showing the lattice-level response of titanium as it underwent plastic deformation and phase transformation. The kinetics of these processes and the influence of oxygen impurities on the deformation behavior will be presented.

  14. In-situ x-ray absorption study of copper films in ground watersolutions

    SciTech Connect

    Kvashnina, K.O.; Butorin, S.M.; Modin, A.; Soroka, I.; Marcellini, M.; Nordgren, J.; Guo, J.-H.; Werme, L.

    2007-10-29

    This study illustrates how the damage from copper corrosion can be reduced by modifying the chemistry of the copper surface environment. The surface modification of oxidized copper films induced by chemical reaction with Cl{sup -} and HCO{sub 3}{sup -} in aqueous solutions was monitored by in situ X-ray absorption spectroscopy. The results show that corrosion of copper can be significantly reduced by adding even a small amount of sodium bicarbonate. The studied copper films corroded quickly in chloride solutions, whereas the same solution containing 1.1 mM HCO{sub 3}{sup -} prevented or slowed down the corrosion processes.

  15. In situ X-ray absorption study of copper films in ground water solutions

    NASA Astrophysics Data System (ADS)

    Kvashnina, K. O.; Butorin, S. M.; Modin, A.; Soroka, I.; Marcellini, M.; Nordgren, J.; Guo, J.-H.; Werme, L.

    2007-10-01

    This study illustrates how the damage from copper corrosion can be reduced by modifying the chemistry of the copper surface environment. The surface modification of oxidized copper films induced by chemical reaction with Cl - and HCO3- in aqueous solutions was monitored by in situ X-ray absorption spectroscopy. The results show that corrosion of copper can be significantly reduced by adding even a small amount of sodium bicarbonate. The studied copper films corroded quickly in chloride solutions, whereas the same solution containing 1.1 mM HCO3- prevented or slowed down the corrosion processes.

  16. In-situ X-ray characterization of the reaction of lithium with InSe

    SciTech Connect

    Levy-Clement, C.; Dahn, J.R.; McKinnon, W.R.; Rioux, J.

    1984-12-01

    The reaction at room temperature of Li with InSe in Li/InSe electrochemical cells was studied using in-situ X-ray diffraction. Li reacts with InSe first to form Li/sub 2/Se and In, then reacts with the In to form InLi. An intermediate phase appears in each of these two steps. The first intermediate phase may be an intercalation compound Li /SUB x/ InSe, the second some In-Li alloy.

  17. In-Situ Silver Acetylide Silver Nitrate Explosive Deposition Measurements Using X-Ray Fluorescence.

    SciTech Connect

    Covert, Timothy Todd

    2014-09-01

    The Light Initiated High Explosive facility utilized a spray deposited coating of silver acetylide - silver nitrate explosive to impart a mechanical shock into targets of interest. A diagnostic was required to measure the explosive deposition in - situ. An X - ray fluorescence spectrometer was deployed at the facility. A measurement methodology was developed to measure the explosive quantity with sufficient accuracy. Through the use of a tin reference material under the silver based explosive, a field calibration relationship has been developed with a standard deviation of 3.2 % . The effect of the inserted tin material into the experiment configuration has been explored.

  18. Development of a speckle-based portable device for in situ metrology of synchrotron X-ray mirrors.

    PubMed

    Kashyap, Yogesh; Wang, Hongchang; Sawhney, Kawal

    2016-09-01

    A portable device for in situ metrology of synchrotron X-ray mirrors based on the near-field speckle scanning technique has been developed. Ultra-high angular sensitivity is achieved by scanning a piece of abrasive paper or filter membrane in the X-ray beam. In addition to the compact setup and ease of implementation, a user-friendly graphical user interface has been developed to ensure that optimizing active X-ray mirrors is simple and fast. The functionality and feasibility of this device have been demonstrated by characterizing and optimizing X-ray mirrors. PMID:27577767

  19. Development of a speckle-based portable device for in situ metrology of synchrotron X-ray mirrors

    PubMed Central

    Kashyap, Yogesh; Wang, Hongchang; Sawhney, Kawal

    2016-01-01

    A portable device for in situ metrology of synchrotron X-ray mirrors based on the near-field speckle scanning technique has been developed. Ultra-high angular sensitivity is achieved by scanning a piece of abrasive paper or filter membrane in the X-ray beam. In addition to the compact setup and ease of implementation, a user-friendly graphical user interface has been developed to ensure that optimizing active X-ray mirrors is simple and fast. The functionality and feasibility of this device have been demonstrated by characterizing and optimizing X-ray mirrors. PMID:27577767

  20. ENERGY DISPERSIVE X-RAY FLUORESCENCE ANALYSIS OF DUST COLLECTED USING A VERTICAL ELUTRIATOR COTTON DUST SAMPLER

    EPA Science Inventory

    X-ray fluorescence (XRF) spectroscopy has been used to analyze trace element concentrations in cotton dusts collected on verticle elutriator filter media. Twenty-three samples collected from ten bales of cotton processed in a model card room have been analyzed. The major elements...

  1. An analytic model for the response of a CZT detector in diagnostic energy dispersive x-ray spectroscopy

    SciTech Connect

    LeClair, Robert J.; Wang Yinkun; Zhao Peiying; Boileau, Michel; Wang, Lilie; Fleurot, Fabrice

    2006-05-15

    A CdZnTe detector (CZTD) can be very useful for measuring diagnostic x-ray spectra. The semiconductor detector does, however, exhibit poor hole transport properties and fluorescence generation upon atomic de-excitations. This article describes an analytic model to characterize these two phenomena that occur when a CZTD is exposed to diagnostic x rays. The analytical detector response functions compare well with those obtained via Monte Carlo calculations. The response functions were applied to 50, 80, and 110 kV x-ray spectra. Two 50 kV spectra were measured; one with no filtration and the other with 1.35 mm Al filtration. The unfiltered spectrum was numerically filtered with 1.35 mm of Al in order to see whether the recovered spectrum resembled the filtered spectrum actually measured. A deviation curve was obtained by subtracting one curve from the other on an energy bin by bin basis. The deviation pattern fluctuated around the zero line when corrections were applied to both spectra. Significant deviations from zero towards the lower energies were observed when the uncorrected spectra were used. Beside visual observations, the exposure obtained using the numerically attenuated unfiltered beam was compared to the exposure calculated with the actual filtered beam. The percent differences were 0.8% when corrections were applied and 25% for no corrections. The model can be used to correct diagnostic x-ray spectra measured with a CdZnTe detector.

  2. Relationship between dislocations and residual stresses in cold-drawn pearlitic steel analyzed by energy-dispersive X-ray diffraction

    SciTech Connect

    Sato, Shigeo; Wagatsuma, Kazuaki; Suzuki, Shigeru; Kumagai, Masayoshi; Imafuku, Muneyuki; Tashiro, Hitoshi; Kajiwara, Kentaro; Shobu, Takahiasa

    2013-09-15

    We analyzed the dislocation distribution of cold-drawn pearlitic-steel wire by using the line-profile analysis based on the energy dispersive X-ray diffraction (EDXD). Although this line-profile analysis requires a high resolution in reciprocal space, the resolution for EDXD is generally poor due to the energy resolution of the detector. Our analysis demonstrated that the resolution in the reciprocal space can be maximized at small scattering angles. Using the line-profile analysis based on the EDXD, the microstructural parameters such as the crystallite size and the dislocation density of the ferrite phase in the pearlitic steel were successfully analyzed. In addition, the distribution of the residual stress of the ferrite phase of a pearlitic steel wire was also analyzed using the EDXD measurement. - Highlights: • Energy dispersive X-ray diffraction is applied to the line-profile analysis. • Distribution of dislocations in ferrite in the pearlitic steel wire is analyzed. • Relationship between dislocations and residual stress is discussed.

  3. Scanning electron microscopy/energy dispersive spectrometry fixedbeam or overscan x-ray microanalysis of particles can miss the real structure: x-ray spectrum image mapping reveals the true nature

    NASA Astrophysics Data System (ADS)

    Newbury, Dale E.; Ritchie, Nicholas W. M.

    2013-05-01

    The typical strategy for analysis of a microscopic particle by scanning electron microscopy/energy dispersive spectrometry x-ray microanalysis (SEM/EDS) is to use a fixed beam placed at the particle center or to continuously overscan to gather an "averaged" x-ray spectrum. While useful, such strategies inevitably concede any possibility of recognizing microstructure within the particle, and such fine scale structure is often critical for understanding the origins, behavior, and fate of particles. Elemental imaging by x-ray mapping has been a mainstay of SEM/EDS analytical practice for many years, but the time penalty associated with mapping with older EDS technology has discouraged its general use and reserved it more for detailed studies that justified the time investment. The emergence of the high throughput, high peak stability silicon drift detector (SDD-EDS) has enabled a more effective particle mapping strategy: "flash" x-ray spectrum image maps can now be recorded in seconds that capture the spatial distribution of major (concentration, C > 0.1 mass fraction) and minor (0.01 <= C <= 0.1) constituents. New SEM/SDD-EDS instrument configurations feature multiple SDDs that view the specimen from widely spaced azimuthal angles. Multiple, simultaneous measurements from different angles enable x-ray spectrometry and mapping that can minimize the strong geometric effects of particles. The NIST DTSA-II software engine is a powerful aid for quantitatively analyzing EDS spectra measured individually as well as for mapping information (available free for Java platforms at: http://www.cstl.nist.gov/div837/837.02/epq/dtsa2/index.html).

  4. In-situ reactive of x-ray optics by glow discharge

    SciTech Connect

    Johnson, E.D.; Garrett, R.F.

    1987-01-01

    We have developed a method of in-situ reactive glow discharge cleaning of x-ray optical surfaces which is capable of complete removal of carbon contamination. Our work is the first to successfully clean an entire optical system in-situ and characterize its performance at short wavelengths (as low as 10 /angstrom/). The apparatus required is quite simple and can easily be fitted to most existing UHV (ultra high vacuum) mirror boxes of monochromators. The advantages of this technique over previously available methods include dramatic improvements in instrument performance and reductions in down time since the whole process typically takes a few days. This paper will briefly describe our results and detail the experimental considerations for application of the technique on different monochromator geometries. Possible improvements and extensions of the technique are also discussed.

  5. Mass Spectrometry Guided In Situ Proteolysis to Obtain Crystals for X-ray Structure Determination

    SciTech Connect

    Gheyi, Tarun; Rodgers, Logan; Romero, Richard; Sauder, J. Michael; Burley, Stephen K.

    2012-04-30

    A strategy for increasing the efficiency of protein crystallization/structure determination with mass spectrometry has been developed. This approach combines insights from limited proteolysis/mass spectrometry and crystallization via in situ proteolysis. The procedure seeks to identify protease-resistant polypeptide chain segments from purified proteins on the time-scale of crystal formation, and subsequently crystallizing the target protein in the presence of the optimal protease at the right relative concentration. We report our experience with 10 proteins of unknown structure, two of which yielded high-resolution X-ray structures. The advantage of this approach comes from its ability to select only those structure determination candidates that are likely to benefit from application of in situ proteolysis, using conditions most likely to result in formation of a stable proteolytic digestion product suitable for crystallization.

  6. In situ azimuthal rotation device for linear dichroism measurements in scanning transmission x-ray microscopy

    NASA Astrophysics Data System (ADS)

    Hernández-Cruz, D.; Hitchcock, A. P.; Tyliszczak, T.; Rousseau, M.-E.; Pézolet, M.

    2007-03-01

    A novel miniature rotation device used in conjunction with a scanning transmission x-ray microscope is described. It provides convenient in situ sample rotation to enable measurements of linear dichroism at high spatial resolution. The design, fabrication, and mechanical characterization are presented. This device has been used to generate quantitative maps of the spatial distribution of the orientation of proteins in several different spider and silkworm silks. Specifically, quantitative maps of the dichroic signal at the C 1s→π*amide transition in longitudinal sections of the silk fibers give information about the spatial orientation, degree of alignment, and spatial distribution of protein peptide bonds. A new approach for analyzing the dichroic signal to extract orientation distributions, in addition to magnitudes of aligned components, is presented and illustrated with results from Nephila clavipes dragline spider silk measured using the in situ rotation device.

  7. Experimental novaculite deformation: interpretation of in-situ X-ray diffraction data using EPSC models

    NASA Astrophysics Data System (ADS)

    Thomas, S.; Willenweber, A.; Cline, C. J.; Sas, M.; Pape, D.; Erickson, B.; Bright, T.; Burnley, P. C.

    2012-12-01

    The deformation behavior of fine-grained polycrystalline quartz (novaculite) was studied experimentally using in-situ X-ray diffraction and theoretically by elastic plastic self consistent modeling (EPSC). Previous experimental work has shown that different subpopulations of crystals experience different stress levels during high pressure deformation and reflection stresses may lead to poor approximations of macroscopic sample stresses, since in-situ diffraction data originates from grain scale phenomena rather than macroscopic sample properties [1]. In this context EPSC models have been utilized to interpret diffraction data, i.e., to independently derive the macroscopic sample load and to directly compare results with diffraction data. In our study a series of novaculite samples with 645 ± 50 wt ppm H2O was deformed in different regimes of disclocation-creep, at 2.5 GPa and up to ~1000 °C, in the D-DIA apparatus at the NSLS X17B2 beamline. In-situ synchrotron X-ray diffraction was used to monitor the sample stress state during controlled deformation and to observe the strain behavior of the individual lattice reflections of novaculite. Lattice strains were calculated from measured lattice spacings. The macroscopic sample strain was determined by sample radiographs. The strains provide information about how individual grains or grain populations react to stress depending on their orientation within the aggregate. We observe a reproducible elastic slope across the series of experiments and a temperature dependence of individual lattice strains and yield strength. In addition, EPSC models were calculated to theoretically determine macroscopic sample stresses and to match measured rheological sample properties with simulations. Depending on deformation conditions measured elastic lattice strains could be matched by activating basal and/or prism and/or pyramidal slip systems of the crystal structure. Here, we present EPSC models, compare macroscopic stresses

  8. In meso in situ serial X-ray crystallography of soluble and membrane proteins

    SciTech Connect

    Huang, Chia-Ying; Olieric, Vincent; Ma, Pikyee; Panepucci, Ezequiel; Diederichs, Kay; Wang, Meitian; Caffrey, Martin

    2015-05-14

    A method for performing high-throughput in situ serial X-ray crystallography with soluble and membrane proteins in the lipid cubic phase is described. It works with microgram quantities of protein and lipid (and ligand when present) and is compatible with the most demanding sulfur SAD phasing. The lipid cubic phase (LCP) continues to grow in popularity as a medium in which to generate crystals of membrane (and soluble) proteins for high-resolution X-ray crystallographic structure determination. To date, the PDB includes 227 records attributed to the LCP or in meso method. Among the listings are some of the highest profile membrane proteins, including the β{sub 2}-adrenoreceptor–G{sub s} protein complex that figured in the award of the 2012 Nobel Prize in Chemistry to Lefkowitz and Kobilka. The most successful in meso protocol to date uses glass sandwich crystallization plates. Despite their many advantages, glass plates are challenging to harvest crystals from. However, performing in situ X-ray diffraction measurements with these plates is not practical. Here, an alternative approach is described that provides many of the advantages of glass plates and is compatible with high-throughput in situ measurements. The novel in meso in situ serial crystallography (IMISX) method introduced here has been demonstrated with AlgE and PepT (alginate and peptide transporters, respectively) as model integral membrane proteins and with lysozyme as a test soluble protein. Structures were solved by molecular replacement and by experimental phasing using bromine SAD and native sulfur SAD methods to resolutions ranging from 1.8 to 2.8 Å using single-digit microgram quantities of protein. That sulfur SAD phasing worked is testament to the exceptional quality of the IMISX diffraction data. The IMISX method is compatible with readily available, inexpensive materials and equipment, is simple to implement and is compatible with high-throughput in situ serial data collection at

  9. In meso in situ serial X-ray crystallography of soluble and membrane proteins

    PubMed Central

    Huang, Chia-Ying; Olieric, Vincent; Ma, Pikyee; Panepucci, Ezequiel; Diederichs, Kay; Wang, Meitian; Caffrey, Martin

    2015-01-01

    The lipid cubic phase (LCP) continues to grow in popularity as a medium in which to generate crystals of membrane (and soluble) proteins for high-resolution X-ray crystallographic structure determination. To date, the PDB includes 227 records attributed to the LCP or in meso method. Among the listings are some of the highest profile membrane proteins, including the β2-adrenoreceptor–Gs protein complex that figured in the award of the 2012 Nobel Prize in Chemistry to Lefkowitz and Kobilka. The most successful in meso protocol to date uses glass sandwich crystallization plates. Despite their many advantages, glass plates are challenging to harvest crystals from. However, performing in situ X-ray diffraction measurements with these plates is not practical. Here, an alternative approach is described that provides many of the advantages of glass plates and is compatible with high-throughput in situ measurements. The novel in meso in situ serial crystallography (IMISX) method introduced here has been demonstrated with AlgE and PepT (alginate and peptide transporters, respectively) as model integral membrane proteins and with lysozyme as a test soluble protein. Structures were solved by molecular replacement and by experimental phasing using bromine SAD and native sulfur SAD methods to resolutions ranging from 1.8 to 2.8 Å using single-digit microgram quantities of protein. That sulfur SAD phasing worked is testament to the exceptional quality of the IMISX diffraction data. The IMISX method is compatible with readily available, inexpensive materials and equipment, is simple to implement and is compatible with high-throughput in situ serial data collection at macromolecular crystallography synchrotron beamlines worldwide. Because of its simplicity and effectiveness, the IMISX approach is likely to supplant existing in meso crystallization protocols. It should prove particularly attractive in the area of ligand screening for drug discovery and development. PMID

  10. In meso in situ serial X-ray crystallography of soluble and membrane proteins.

    PubMed

    Huang, Chia Ying; Olieric, Vincent; Ma, Pikyee; Panepucci, Ezequiel; Diederichs, Kay; Wang, Meitian; Caffrey, Martin

    2015-06-01

    The lipid cubic phase (LCP) continues to grow in popularity as a medium in which to generate crystals of membrane (and soluble) proteins for high-resolution X-ray crystallographic structure determination. To date, the PDB includes 227 records attributed to the LCP or in meso method. Among the listings are some of the highest profile membrane proteins, including the β2-adrenoreceptor-Gs protein complex that figured in the award of the 2012 Nobel Prize in Chemistry to Lefkowitz and Kobilka. The most successful in meso protocol to date uses glass sandwich crystallization plates. Despite their many advantages, glass plates are challenging to harvest crystals from. However, performing in situ X-ray diffraction measurements with these plates is not practical. Here, an alternative approach is described that provides many of the advantages of glass plates and is compatible with high-throughput in situ measurements. The novel in meso in situ serial crystallography (IMISX) method introduced here has been demonstrated with AlgE and PepT (alginate and peptide transporters, respectively) as model integral membrane proteins and with lysozyme as a test soluble protein. Structures were solved by molecular replacement and by experimental phasing using bromine SAD and native sulfur SAD methods to resolutions ranging from 1.8 to 2.8 Å using single-digit microgram quantities of protein. That sulfur SAD phasing worked is testament to the exceptional quality of the IMISX diffraction data. The IMISX method is compatible with readily available, inexpensive materials and equipment, is simple to implement and is compatible with high-throughput in situ serial data collection at macromolecular crystallography synchrotron beamlines worldwide. Because of its simplicity and effectiveness, the IMISX approach is likely to supplant existing in meso crystallization protocols. It should prove particularly attractive in the area of ligand screening for drug discovery and development. PMID:26057665

  11. Development of an in situ temperature stage for synchrotron X-ray spectromicroscopy

    NASA Astrophysics Data System (ADS)

    Chakraborty, R.; Serdy, J.; West, B.; Stuckelberger, M.; Lai, B.; Maser, J.; Bertoni, M. I.; Culpepper, M. L.; Buonassisi, T.

    2015-11-01

    In situ characterization of micro- and nanoscale defects in polycrystalline thin-film materials is required to elucidate the physics governing defect formation and evolution during photovoltaic device fabrication and operation. X-ray fluorescence spectromicroscopy is particularly well-suited to study defects in compound semiconductors, as it has a large information depth appropriate to study thick and complex materials, is sensitive to trace amounts of atomic species, and provides quantitative elemental information, non-destructively. Current in situ methods using this technique typically require extensive sample preparation. In this work, we design and build an in situ temperature stage to study defect kinetics in thin-film solar cells under actual processing conditions, requiring minimal sample preparation. Careful selection of construction materials also enables controlled non-oxidizing atmospheres inside the sample chamber such as H2Se and H2S. Temperature ramp rates of up to 300 °C/min are achieved, with a maximum sample temperature of 600 °C. As a case study, we use the stage for synchrotron X-ray fluorescence spectromicroscopy of CuInxGa1-xSe2 (CIGS) thin-films and demonstrate predictable sample thermal drift for temperatures 25-400 °C, allowing features on the order of the resolution of the measurement technique (125 nm) to be tracked while heating. The stage enables previously unattainable in situ studies of nanoscale defect kinetics under industrially relevant processing conditions, allowing a deeper understanding of the relationship between material processing parameters, materials properties, and device performance.

  12. Development of an in situ temperature stage for synchrotron X-ray spectromicroscopy

    SciTech Connect

    Chakraborty, R. E-mail: buonassisi@mit.edu; Serdy, J.; Culpepper, M. L.; Buonassisi, T. E-mail: buonassisi@mit.edu; West, B.; Stuckelberger, M.; Bertoni, M. I.; Lai, B.; Maser, J.

    2015-11-15

    In situ characterization of micro- and nanoscale defects in polycrystalline thin-film materials is required to elucidate the physics governing defect formation and evolution during photovoltaic device fabrication and operation. X-ray fluorescence spectromicroscopy is particularly well-suited to study defects in compound semiconductors, as it has a large information depth appropriate to study thick and complex materials, is sensitive to trace amounts of atomic species, and provides quantitative elemental information, non-destructively. Current in situ methods using this technique typically require extensive sample preparation. In this work, we design and build an in situ temperature stage to study defect kinetics in thin-film solar cells under actual processing conditions, requiring minimal sample preparation. Careful selection of construction materials also enables controlled non-oxidizing atmospheres inside the sample chamber such as H{sub 2}Se and H{sub 2}S. Temperature ramp rates of up to 300 °C/min are achieved, with a maximum sample temperature of 600 °C. As a case study, we use the stage for synchrotron X-ray fluorescence spectromicroscopy of CuIn{sub x}Ga{sub 1−x}Se{sub 2} (CIGS) thin-films and demonstrate predictable sample thermal drift for temperatures 25–400 °C, allowing features on the order of the resolution of the measurement technique (125 nm) to be tracked while heating. The stage enables previously unattainable in situ studies of nanoscale defect kinetics under industrially relevant processing conditions, allowing a deeper understanding of the relationship between material processing parameters, materials properties, and device performance.

  13. Simulations of in situ x-ray diffraction from uniaxially compressed highly textured polycrystalline targets

    SciTech Connect

    McGonegle, David Wark, Justin S.; Higginbotham, Andrew; Milathianaki, Despina; Remington, Bruce A.

    2015-08-14

    A growing number of shock compression experiments, especially those involving laser compression, are taking advantage of in situ x-ray diffraction as a tool to interrogate structure and microstructure evolution. Although these experiments are becoming increasingly sophisticated, there has been little work on exploiting the textured nature of polycrystalline targets to gain information on sample response. Here, we describe how to generate simulated x-ray diffraction patterns from materials with an arbitrary texture function subject to a general deformation gradient. We will present simulations of Debye-Scherrer x-ray diffraction from highly textured polycrystalline targets that have been subjected to uniaxial compression, as may occur under planar shock conditions. In particular, we study samples with a fibre texture, and find that the azimuthal dependence of the diffraction patterns contains information that, in principle, affords discrimination between a number of similar shock-deformation mechanisms. For certain cases, we compare our method with results obtained by taking the Fourier transform of the atomic positions calculated by classical molecular dynamics simulations. Illustrative results are presented for the shock-induced α–ϵ phase transition in iron, the α–ω transition in titanium and deformation due to twinning in tantalum that is initially preferentially textured along [001] and [011]. The simulations are relevant to experiments that can now be performed using 4th generation light sources, where single-shot x-ray diffraction patterns from crystals compressed via laser-ablation can be obtained on timescales shorter than a phonon period.

  14. In situ x-ray photoemission studies of the oxidation of Y-Ba-Cu films

    SciTech Connect

    Price, R.J.; Jackman, R.B.; Foord, J.S.

    1988-12-15

    X-ray photoemission has been used to investigate the formation of Y-Ba-Cu films on Si(100) and as an in situ probe of their subsequent oxidation to yield the associated oxide ceramic. The layers are prepared by coevaporation of the metallic components under ultrahigh vacuum, and pure alloy phases can be deposited at 300 K; reaction with the underlying substrate resulting in loss of Cu and incorporation by Si in the film takes place, however, at higher temperatures. Room-temperature oxidation stabilizes the film against this interaction and results in the preferential oxidation and surface segregation of barium at the expense of Cu. This segregation process becomes even more apparent during higher temperature (approx.600 K) oxidation reactions. Chemical shifts and associated effects in x-ray photoelectron spectra are used to infer information on the chemical changes that occur in the film as oxidation proceeds. The thin-film phases prepared in situ in this work reveal a very similar surface composition to bulk superconducting samples prepared ex situ. This suggests that the surface segregation in bulk samples does not simply result from reaction with species such as water vapor, but instead may represent an equilibrium state of the oxide-oxygen interface.

  15. An experimental system for high temperature X-ray diffraction studies with in situ mechanical loading

    PubMed Central

    Oswald, Benjamin B.; Schuren, Jay C.; Pagan, Darren C.; Miller, Matthew P.

    2013-01-01

    An experimental system with in situ thermomechanical loading has been developed to enable high energy synchrotron x-ray diffraction studies of crystalline materials. The system applies and maintains loads of up to 2250 N in uniaxial tension or compression at a frequency of up to 100 Hz. The furnace heats the specimen uniformly up to a maximum temperature of 1200 °C in a variety of atmospheres (oxidizing, inert, reducing) that, combined with in situ mechanical loading, can be used to mimic processing and operating conditions of engineering components. The loaded specimen is reoriented with respect to the incident beam of x-rays using two rotational axes to increase the number of crystal orientations interrogated. The system was used at the Cornell High Energy Synchrotron Source to conduct experiments on single crystal silicon and polycrystalline Low Solvus High Refractory nickel-based superalloy. The data from these experiments provide new insights into how stresses evolve at the crystal scale during thermomechanical loading and complement the development of high-fidelity material models. PMID:23556825

  16. In Situ X-ray Reflectivity Studies of Protein Adsorption onto Functionalized Surfaces

    NASA Astrophysics Data System (ADS)

    Richter, Andrew

    2007-03-01

    The adsorption of protein films onto solid surfaces, both artificial and naturally occurring, have been widely studied using a variety of techniques due to their importance in medicine, biomedical applications, and the general understanding of protein structure and function. What have yet to be performed are in situ, time-resolved, high-resolution structural studies of these systems. We have begun a project that uses the technique of in situ x-ray reflectivity to obtain highly resolved structural information with time resolution on the order of minutes. This talk will present our first findings of serum albumin and immunoglobulin G films on hydrophobic self-assembled monolayers. The protein films are readily observable, showing extensive denaturing after adsorption with a slow decay of density into the aqueous solution. Additionally, a thin low-density region that occurs between the hydrophobic film and the solution persists after protein deposition. Comparisons to films that are removed from solution, the influence of solution concentration, the effects of x-ray damage, and the time scales for protein film formation and evolution will also be discussed.

  17. In situ high-resolution X-ray photoelectron spectroscopy - Fundamental insights in surface reactions

    NASA Astrophysics Data System (ADS)

    Papp, Christian; Steinrück, Hans-Peter

    2013-11-01

    Since the advent of third generation synchrotron light sources optimized for providing soft X-rays up to 2 keV, X-ray photoelectron spectroscopy (XPS) has been developed to be an outstanding tool to study surface properties and surface reactions at an unprecedented level. The high resolution allows identifying various surface species, and for small molecules even the vibrational fine structure can be resolved in the XP spectra. The high photon flux reduces the required measuring time per spectrum to the domain of a few seconds or even less, which enables to follow surface processes in situ. Moreover, it also provides access to very small coverages down to below 0.1% of a monolayer, enabling the investigation of minority species or processes at defect sites. The photon energy can be adjusted according to the requirement of a particular experiment, i.e., to maximize or minimize the surface sensitivity or the photoionization cross-section of the substrate or the adsorbate. For a few instruments worldwide, a next step forward was taken by combining in situ high-resolution spectrometers with supersonic molecular beams. These beams allow to control and vary the kinetic and internal energies of the incident molecules and provide a local pressure of up to ~10-5 mbar, which can be switched on and off in a controllable way, thus offering a well-defined time structure to study adsorption or reaction processes.

  18. Chemometric classification of gunshot residues based on energy dispersive X-ray microanalysis and inductively coupled plasma analysis with mass-spectrometric detection

    NASA Astrophysics Data System (ADS)

    Steffen, S.; Otto, M.; Niewoehner, L.; Barth, M.; Bro¿żek-Mucha, Z.; Biegstraaten, J.; Horváth, R.

    2007-09-01

    A gunshot residue sample that was collected from an object or a suspected person is automatically searched for gunshot residue relevant particles. Particle data (such as size, morphology, position on the sample for manual relocation, etc.) as well as the corresponding X-ray spectra and images are stored. According to these data, particles are classified by the analysis-software into different groups: 'gunshot residue characteristic', 'consistent with gunshot residue' and environmental particles, respectively. Potential gunshot residue particles are manually checked and - if necessary - confirmed by the operating forensic scientist. As there are continuing developments on the ammunition market worldwide, it becomes more and more difficult to assign a detected particle to a particular ammunition brand. As well, the differentiation towards environmental particles similar to gunshot residue is getting more complex. To keep external conditions unchanged, gunshot residue particles were collected using a specially designed shooting device for the test shots revealing defined shooting distances between the weapon's muzzle and the target. The data obtained as X-ray spectra of a number of particles (3000 per ammunition brand) were reduced by Fast Fourier Transformation and subjected to a chemometric evaluation by means of regularized discriminant analysis. In addition to the scanning electron microscopy in combination with energy dispersive X-ray microanalysis results, isotope ratio measurements based on inductively coupled plasma analysis with mass-spectrometric detection were carried out to provide a supplementary feature for an even lower risk of misclassification.

  19. Rigorous quantitative elemental microanalysis by scanning electron microscopy/energy dispersive x-ray spectrometry (SEM/EDS) with spectrum processing by NIST DTSA-II

    NASA Astrophysics Data System (ADS)

    Newbury, Dale E.; Ritchie, Nicholas W. M.

    2014-09-01

    Quantitative electron-excited x-ray microanalysis by scanning electron microscopy/silicon drift detector energy dispersive x-ray spectrometry (SEM/SDD-EDS) is capable of achieving high accuracy and high precision equivalent to that of the high spectral resolution wavelength dispersive x-ray spectrometer even when severe peak interference occurs. The throughput of the SDD-EDS enables high count spectra to be measured that are stable in calibration and resolution (peak shape) across the full deadtime range. With this high spectral stability, multiple linear least squares peak fitting is successful for separating overlapping peaks and spectral background. Careful specimen preparation is necessary to remove topography on unknowns and standards. The standards-based matrix correction procedure embedded in the NIST DTSA-II software engine returns quantitative results supported by a complete error budget, including estimates of the uncertainties from measurement statistics and from the physical basis of the matrix corrections. NIST DTSA-II is available free for Java-platforms at: http://www.cstl.nist.gov/div837/837.02/epq/dtsa2/index.html).

  20. Misidentification of major constituents by automatic qualitative energy dispersive X-ray microanalysis: a problem that threatens the credibility of the analytical community.

    PubMed

    Newbury, Dale E

    2005-12-01

    Automatic qualitative analysis for peak identification is a standard feature of virtually all modern computer-aided analysis software for energy dispersive X-ray spectrometry with electron excitation. Testing of recently installed systems from four different manufacturers has revealed the occasional occurrence of misidentification of peaks of major constituents whose concentrations exceeded 0.1 mass fraction (10 wt%). Test materials where peak identification failures were observed included ZnS, KBr, FeS2, tantalum-niobium alloy, NIST Standard Reference Material 482 (copper-gold alloy), Bi2Te3, uranium-rhodium alloys, platinum-chromium alloy, GaAs, and GaP. These misidentifications of major constituents were exacerbated when the incident beam energy was 10 keV or lower, which restricted or excluded the excitation of the high photon energy K- and L-shell X-rays where multiple peaks, for example, Kalpha (K-L2,3)-Kbeta (K-M2,3); Lalpha (L3-M4,5)-Lbeta (L2-M4)-Lgamma (L2-N4), are well resolved and amenable to identification with high confidence. These misidentifications are so severe as to properly qualify as blunders that present a serious challenge to the credibility of this critical analytical technique. Systematic testing of a peak identification system with a suite of diverse materials can reveal the specific elements and X-ray peaks where failures are likely to occur. PMID:17481333

  1. Misidentification of Major Constituents by Automatic Qualitative Energy Dispersive X-ray Microanalysis: A Problem that Threatens the Credibility of the Analytical Community

    NASA Astrophysics Data System (ADS)

    Newbury*, Dale E.

    2005-12-01

    Automatic qualitative analysis for peak identification is a standard feature of virtually all modern computer-aided analysis software for energy dispersive X-ray spectrometry with electron excitation. Testing of recently installed systems from four different manufacturers has revealed the occasional occurrence of misidentification of peaks of major constituents whose concentrations exceeded 0.1 mass fraction (10 wt%). Test materials where peak identification failures were observed included ZnS, KBr, FeS2, tantalum-niobium alloy, NIST Standard Reference Material 482 (copper gold alloy), Bi2Te3, uranium rhodium alloys, platinum chromium alloy, GaAs, and GaP. These misidentifications of major constituents were exacerbated when the incident beam energy was 10 keV or lower, which restricted or excluded the excitation of the high photon energy K- and L-shell X-rays where multiple peaks, for example, K[alpha] (K-L2,3) K[beta] (K-M2,3); L[alpha] (L3-M4,5) L[beta] (L2-M4) L[gamma] (L2-N4), are well resolved and amenable to identification with high confidence. These misidentifications are so severe as to properly qualify as blunders that present a serious challenge to the credibility of this critical analytical technique. Systematic testing of a peak identification system with a suite of diverse materials can reveal the specific elements and X-ray peaks where failures are likely to occur.

  2. Development of in-line furnace for in-situ nanoscale resolution x-ray microscopy

    NASA Astrophysics Data System (ADS)

    Eng, Christopher; Chen-Wiegart, Yu-Chen K.; Wang, Jun

    2013-09-01

    Full field transmission x-ray microscopy (TXM) is a newly developed x-ray imaging technique to provide quantitative and non-destructive 3D characterization of the complex microstructure of materials at nanometer resolution. A key missing component is an in situ apparatus enabling the imaging of the complex structural evolution of the materials and to correlate the structural change with a material's functionality under real operating conditions. This work describes the design of an environmental cell which satisfies the requirements for in situ TXM studies. The limited space within the TXM presents a spatial constraint which prohibits the use of conventional heaters, as well as requiring consideration in designing for safe and controlled operation of the system and alignment of the cell with the beam. A gravity drip-fed water cooling jacket was installed in place around the heating module to maintain critical components of the microscope at safe operating temperatures. A motion control system consisting of pulse width modulated DC motor driven XYZ translation stages was developed to facilitate fine alignment of the cell. Temperature of the sample can be controlled remotely and accurately through a controller to temperatures as high as 1200 K. Heating zone measurement was carried out and shows a 500 x 500 x 500 μm3 homogeneous zone volume for sample area, which is a critical parameter to ensure accurate observation of structural evolution at nanometer scale with a sample in size of tens of microns. Application on Ni particles for in situ oxidation experiment and dehydrogenation of aluminum hydride is also discussed.

  3. Synchrotron Radiation and Energy Dispersive X-Ray Fluorescence Applications on Elemental Distribution in Human Hair and Bones

    SciTech Connect

    Carvalho, M.L.; Marques, A.F.; Brito, J.

    2003-01-24

    This work is an application of synchrotron microprobe X- Ray fluorescence in order to study elemental distribution along human hair samples of contemporary citizens. Furthermore, X-Ray fluorescence spectrometry is also used to analyse human bones of different historical periods: Neolithic and contemporary subjects. The elemental content in the bones allowed us to conclude about environmental contamination, dietary habits and health status influence in the corresponding citizens. All samples were collected post-mortem. Quantitative analysis was performed for Mn, Fe, Co, Ni, Cu, Zn, Br, Rb, Sr and Pb. Mn and Fe concentration were much higher in bones from pre-historic periods. On the contrary, Pb bone concentrations of contemporary subjects are much higher than in pre-historical ones, reaching 100 {mu}g g-1, in some cases. Very low concentrations for Co, Ni, Br and Rb were found in all the analysed samples. Cu concentrations, allows to distinguish Chalcolithic bones from the Neolithic ones. The distribution of trace elements along human hair was studied for Pb and the obtained pattern was consistent with the theoretical model, based on the diffusion of this element from the root and along the hair. Therefore, the higher concentrations in hair for Pb of contemporary individuals were also observed in the bones of citizens of the same sampling sites. All samples were analysed directly without any chemical treatment.

  4. Neighborite Under High Pressure: In Situ Angle Dispersive X-ray Diffraction Study Using Synchrotron Radiation

    NASA Astrophysics Data System (ADS)

    Liu, H.; Chen, J.; Weidner, D.; Hu, J.; Meng, Y.; Mao, H.

    2003-12-01

    The neighborite (NaMgF3) is an ideal analogue model for silicate perovskite (MgSiO3) due to the similarities between their crystal and electronic structures. The advantage of the analogue study is that the weaker bonding feature of neighborite grants us the opportunity to simulate behavior of silicate perovskite at lower mantlei. e.high pressure and high temperature condition, at relatively lower P-T conditions. The previous high pressure studies for neighborite were reported by Zhao et al [1, 2]. Energy dispersive x-ray diffraction data were achieved within 10GPa and 1000oC, while angle dispersive x-ray diffraction data were obtained only at 4.9GPa and room temperature.More information of atomic position change is required to reveal the role of MgF6 octahedral framework tilting during its phase transition process responding to heating andcompressing. Thus the high-resolution monochromatic x-ray powder diffraction studies on NaMgF3 perovskite at high pressure were carried out using diamond anvil cell at X17C of National Synchrotron Light Source (Brookhaven) and HPCAT of Advance Photon Source (Argonne). The orthorhombic structure keeps stable under pressure up to 30 GPa, and the crystal structure is refined using Rietveld method. The result indicates that tilting angle of the MgF6 octahedral framework increases continually while the octahedral Mg-F bond length decreases slightly with increasing pressure.Difference between the tilting angles derived from macro-structure (lattice parameters) and from micro-structure (atomic positions), as well as the trend of change in the tilting angle with temperature and pressureare discussed. [1]. Zhao YS, Weidner DJ, Ko JD, Leinenweber K, Liu X, Li BS, Meng Y,Pacalo REG, Vaughan MT, Wang YB, Yeganehhaeri A,J.Geophys. Res. Solid Earth, 99 (1994) 2871. [2]. Zhao YS, Parise JB, Wang YB, Kusaba K, Vaughan MT, Weidner DJ, Kikegawa T, Chen J, Shimomura O,Am.Miner., 79 (1994) 615.

  5. Atomic Structure of Pt3Ni Nanoframe Electrocatalysts by in Situ X-ray Absorption Spectroscopy.

    PubMed

    Becknell, Nigel; Kang, Yijin; Chen, Chen; Resasco, Joaquin; Kornienko, Nikolay; Guo, Jinghua; Markovic, Nenad M; Somorjai, Gabor A; Stamenkovic, Vojislav R; Yang, Peidong

    2015-12-23

    Understanding the atomic structure of a catalyst is crucial to exposing the source of its performance characteristics. It is highly unlikely that a catalyst remains the same under reaction conditions when compared to as-synthesized. Hence, the ideal experiment to study the catalyst structure should be performed in situ. Here, we use X-ray absorption spectroscopy (XAS) as an in situ technique to study Pt3Ni nanoframe particles which have been proven to be an excellent electrocatalyst for the oxygen reduction reaction (ORR). The surface characteristics of the nanoframes were probed through electrochemical hydrogen underpotential deposition and carbon monoxide electrooxidation, which showed that nanoframe surfaces with different structure exhibit varying levels of binding strength to adsorbate molecules. It is well-known that Pt-skin formation on Pt-Ni catalysts will enhance ORR activity by weakening the binding energy between the surface and adsorbates. Ex situ and in situ XAS results reveal that nanoframes which bind adsorbates more strongly have a rougher Pt surface caused by insufficient segregation of Pt to the surface and consequent Ni dissolution. In contrast, nanoframes which exhibit extremely high ORR activity simultaneously demonstrate more significant segregation of Pt over Ni-rich subsurface layers, allowing better formation of the critical Pt-skin. This work demonstrates that the high ORR activity of the Pt3Ni hollow nanoframes depends on successful formation of the Pt-skin surface structure. PMID:26652294

  6. Calibration of a compact XUV soft X-ray monochromator with a digital autocollimator in situ.

    PubMed

    Yuh, Jih Young; Lin, Shang Wei; Huang, Liang Jen; Lee, Long Life

    2016-09-01

    A digital autocollimator of resolution 0.1 µrad (0.02 arcsec) serves as a handy correction tool for calibrating the angular uncertainty during angular and lateral movements of gratings inside a monochromator chamber under ultra-high vacuum. The photon energy dispersed from the extreme ultraviolet (XUV) to the soft X-ray region of the synchrotron beamline at the Taiwan Light Source was monitored using molecular ionization spectra at high resolution as energy references that correlate with the fine angular steps during grating rotation. The angular resolution of the scanning mechanism was <0.3 µrad, which results in an energy shift of 80 meV at 867 eV. The angular uncertainties caused by the lateral movement during a grating exchange were decreased from 2.2 µrad to 0.1 µrad after correction. The proposed method provides a simple solution for on-site beamline diagnostics of highly precise multi-axis optical manipulating instruments at synchrotron facilities and in-house laboratories. PMID:27577780

  7. Near-isothermal furnace for in situ and real time X-ray radiography solidification experiments

    NASA Astrophysics Data System (ADS)

    Becker, M.; Dreißigacker, C.; Klein, S.; Kargl, F.

    2015-06-01

    In this paper, we present a newly developed near-isothermal X-ray transparent furnace for in situ imaging of solidification processes in thin metallic samples. We show that the furnace is ideally suited to study equiaxed microstructure evolution and grain interaction. To observe the growth dynamics of equiaxed dendritic structures, a minimal temperature gradient across the sample is required. A uniform thermal profile inside a circular sample is achieved by positioning the sample in the center of a cylindrical furnace body surrounded by a circular heater arrangement. Performance tests with the hypo-eutectic Al-15wt.%Cu and the near-eutectic Al-33wt.%Cu alloys validate the near-isothermal character of the sample environment. Controlled cooling rates of less than 0.5 K min-1 up to 10 K min-1 can be achieved in a temperature range of 720 K-1220 K. Integrated in our rotatable laboratory X-ray facility, X-RISE, the furnace provides a large field of view of 10.5 mm in diameter and a high spatial resolution of ˜4 μm. With the here presented furnace, equiaxed dendrite growth models can be rigorously tested against experiments on metal alloys by, e.g., enabling dendrite growth velocities to be determined as a function of undercooling or solutal fields in front of the growing dendrite to be measured.

  8. Near-isothermal furnace for in situ and real time X-ray radiography solidification experiments

    SciTech Connect

    Becker, M. Dreißigacker, C.; Klein, S.; Kargl, F.

    2015-06-15

    In this paper, we present a newly developed near-isothermal X-ray transparent furnace for in situ imaging of solidification processes in thin metallic samples. We show that the furnace is ideally suited to study equiaxed microstructure evolution and grain interaction. To observe the growth dynamics of equiaxed dendritic structures, a minimal temperature gradient across the sample is required. A uniform thermal profile inside a circular sample is achieved by positioning the sample in the center of a cylindrical furnace body surrounded by a circular heater arrangement. Performance tests with the hypo-eutectic Al-15wt.%Cu and the near-eutectic Al-33wt.%Cu alloys validate the near-isothermal character of the sample environment. Controlled cooling rates of less than 0.5 K min{sup −1} up to 10 K min{sup −1} can be achieved in a temperature range of 720 K–1220 K. Integrated in our rotatable laboratory X-ray facility, X-RISE, the furnace provides a large field of view of 10.5 mm in diameter and a high spatial resolution of ∼4 μm. With the here presented furnace, equiaxed dendrite growth models can be rigorously tested against experiments on metal alloys by, e.g., enabling dendrite growth velocities to be determined as a function of undercooling or solutal fields in front of the growing dendrite to be measured.

  9. An apparatus for in situ x-ray scattering measurements during polymer injection molding

    NASA Astrophysics Data System (ADS)

    Rendon, Stanley; Fang, Jun; Burghardt, Wesley R.; Bubeck, Robert A.

    2009-04-01

    We report a novel instrument for synchrotron-based in situ x-ray scattering measurements during injection molding processing. It allows direct, real-time monitoring of molecular-scale structural evolution in polymer materials undergoing a complex processing operation. The instrument is based on a laboratory-scale injection molding machine, and employs customized mold tools designed to allow x-ray access during mold filling and subsequent solidification, while providing sufficient robustness to withstand high injection pressures. The use of high energy, high flux synchrotron radiation, and a fast detector allows sufficiently rapid data acquisition to resolve time-dependent orientation dynamics in this transient process. Simultaneous monitoring of temperature and pressure signals allows transient scattering data to be referenced to various stages of the injection molding cycle. Representative data on a commercial liquid crystalline polymer, Vectra® B950, are presented to demonstrate the features of this apparatus; however, it may find application in a wide range of polymeric materials such as nanocomposites, semicrystalline polymers and fiber-reinforced thermoplastics.

  10. Near-isothermal furnace for in situ and real time X-ray radiography solidification experiments.

    PubMed

    Becker, M; Dreißigacker, C; Klein, S; Kargl, F

    2015-06-01

    In this paper, we present a newly developed near-isothermal X-ray transparent furnace for in situ imaging of solidification processes in thin metallic samples. We show that the furnace is ideally suited to study equiaxed microstructure evolution and grain interaction. To observe the growth dynamics of equiaxed dendritic structures, a minimal temperature gradient across the sample is required. A uniform thermal profile inside a circular sample is achieved by positioning the sample in the center of a cylindrical furnace body surrounded by a circular heater arrangement. Performance tests with the hypo-eutectic Al-15wt.%Cu and the near-eutectic Al-33wt.%Cu alloys validate the near-isothermal character of the sample environment. Controlled cooling rates of less than 0.5 K min(-1) up to 10 K min(-1) can be achieved in a temperature range of 720 K-1220 K. Integrated in our rotatable laboratory X-ray facility, X-RISE, the furnace provides a large field of view of 10.5 mm in diameter and a high spatial resolution of ∼4 μm. With the here presented furnace, equiaxed dendrite growth models can be rigorously tested against experiments on metal alloys by, e.g., enabling dendrite growth velocities to be determined as a function of undercooling or solutal fields in front of the growing dendrite to be measured. PMID:26133847

  11. Use of x-ray fluorescence for in-situ detection of metals

    NASA Astrophysics Data System (ADS)

    Elam, W. T. E.; Whitlock, Robert R.; Gilfrich, John V.

    1995-01-01

    X-ray fluorescence (XRF) is a well-established, non-destructive method of determining elemental concentrations at ppm levels in complex samples. It can operate in atmosphere with no sample preparation, and provides accuracies of 1% or better under optimum conditions. This report addresses two sets of issues concerning the use of x-ray fluorescence as a sensor technology for the cone penetrometer, for shipboard waste disposal, or for other in-situ, real- time environmental applications. The first issue concerns the applicability of XRF to these applications, and includes investigation of detection limits and matrix effects. We have evaluated the detection limits and quantitative accuracy of a sensor mock-up for metals in soils under conditions expected in the field. In addition, several novel ways of improving the lower limits of detection to reach the drinking water regulatory limits have been explored. The second issue is the engineering involved with constructing a spectrometer within the 1.75 inch diameter of the penetrometer pipe, which is the most rigorous physical constraint. Only small improvements over current state-of-the-art are required. Additional advantages of XRF are that no radioactive sources or hazardous materials are used in the sensor design, and no reagents or any possible sources of ignition are involved.

  12. In-situ x-ray characterization of wurtzite formation in GaAs nanowires

    SciTech Connect

    Krogstrup, Peter; Hannibal Madsen, Morten; Nygaard, Jesper; Feidenhans'l, Robert; Hu Wen; Kozu, Miwa; Nakata, Yuka; Takahasi, Masamitu

    2012-02-27

    In-situ monitoring of the crystal structure formation during Ga-assisted GaAs nanowire growth on Si(111) substrates has been performed in a combined molecular beam epitaxy growth and x-ray characterization experiment. Under Ga rich conditions, we show that an increase in the V/III ratio increases the formation rate of the wurtzite structure. Moreover, the response time for changes in the structural phase formation to changes in the beam fluxes is observed to be much longer than predicted time scales of adatom kinetics and liquid diffusion. This suggests that the morphology of the growth interface plays the key role for the relative growth structure formation rates.

  13. In situ surface X-ray scattering of stepped surface of platinum: Pt(311).

    PubMed

    Nakahara, Akira; Nakamura, Masashi; Sumitani, Kazushi; Sakata, Osami; Hoshi, Nagahiro

    2007-10-23

    Surface structure of a stepped surface of Pt, Pt(311) (=2(100)-(111)), has been determined under potential control in 0.1 M HClO4 with the use of in situ surface X-ray scattering (SXS). The crystal truncation rods (CTRs) are reproduced well with the (1x2) missing-row model. Relaxation of surface layers, which is observed on the low-index planes of Pt, is not found on Pt(311) in the "adsorbed hydrogen region". CTRs at 0.10 (RHE) have the same feature as those at 0.50 V, showing that the surface layers of Pt(311) have no potential dependence. Scanning tunneling microscopy (STM) also supports the (1x2) structure of Pt(311) in 0.1 M HClO4. PMID:17902717

  14. Kinetics of Methane Hydrate Decomposition Studied via in Situ Low Temperature X-ray Powder Diffraction

    SciTech Connect

    Everett, Susan M; Rawn, Claudia J; Keffer, David J.; Mull, Derek L; Payzant, E Andrew; Phelps, Tommy Joe

    2013-01-01

    Gas hydrates are known to have a slowed decomposition rate at ambient pressure and temperatures below the melting point of ice termed self-preservation or anomalous preservation. As hydrate exothermically decomposes, gas is released and water of the clathrate cages transforms into ice. Two regions of slowed decomposition for methane hydrate, 180 200 K and 230 260 K, were observed, and the kinetics were studied by in situ low temperature x-ray powder diffraction. The kinetic constants for ice formation from methane hydrate were determined by the Avrami model within each region and activation energies, Ea, were determined by the Arrhenius plot. Ea determined from the data for 180 200 K was 42 kJ/mol and for 230 260 K was 22 kJ/mol. The higher Ea in the colder temperature range was attributed to a difference in the microstructure of ice between the two regions.

  15. Hydride reorientation in Zircaloy-4 examined by in situ synchrotron X-ray diffraction

    NASA Astrophysics Data System (ADS)

    Weekes, H. E.; Jones, N. G.; Lindley, T. C.; Dye, D.

    2016-09-01

    The phenomenon of stress-reorientation has been investigated using in situ X-ray diffraction during the thermomechanical cycling of hydrided Zircaloy-4 tensile specimens. Results have shown that loading along a sample's transverse direction (TD) leads to a greater degree of hydride reorientation when compared to rolling direction (RD)-aligned samples. The elastic lattice micro-strains associated with radially oriented hydrides have been revealed to be greater than those oriented circumferentially, a consequence of strain accommodation. Evidence of hydride redistribution after cycling, to α-Zr grains oriented in a more favourable orientation when under an applied stress, has also been observed and its behaviour has been found to be highly dependent on the loading axis. Finally, thermomechanical loading across multiple cycles has been shown to reduce the difference in terminal solid solubility of hydrogen during dissolution (TSSD,H) and precipitation (TSSP,H).

  16. Tracking the catalyzed growth process of nanowires by in situ x-ray diffraction

    NASA Astrophysics Data System (ADS)

    Kirkham, Melanie; Wang, Zhong Lin; Snyder, Robert L.

    2010-07-01

    Quasi-one-dimensional nanostructures of silicon, oxides, and other materials show great promise for a variety of applications. These nanostructures are commonly grown using metal catalyst nanoparticles. This paper investigates the growth mechanism of Au-catalyzed Si nanowires through in situ x-ray diffraction, and the results are compared to previously studied Au-catalyzed ZnO nanorods. The Si nanowires were found to grow from molten catalyst particles, however, the ZnO nanorods were found to grow from solid catalyst particles through a surface diffusion process. From this comparison, the relative bonding types of the catalyst and source material are determined to have a significant effect on the growth mechanism.

  17. In situ X-ray polymerization: from swollen lamellae to polymer-surfactant complexes.

    PubMed

    Agzenai, Yahya; Lindman, Björn; Alfredsson, Viveka; Topgaard, Daniel; Renamayor, Carmen S; Pacios, Isabel E

    2014-01-30

    The influence of the monomer diallyldimethylammonium chloride (D) on the lamellar liquid crystal formed by the anionic surfactant aerosol OT (AOT) and water is investigated, determining the lamellar spacings by SAXS and the quadrupolar splittings by deuterium NMR, as a function of the D or AOT concentrations. The cationic monomer D induces a destabilization of the AOT lamellar structure such that, at a critical concentration higher than 5 wt %, macroscopic phase separation takes place. When the monomer, which is dissolved in the AOT lamellae, is polymerized in situ by X-ray initiation, a new collapsed lamellar phase appears, corresponding to the complexation of the surfactant with the resulting polymer. A theoretical model is employed to analyze the variation of the interactions between the AOT bilayers and the stability of the lamellar structure. PMID:24410395

  18. In situ synchrotron x-ray studies of LiMn{sub 2}O{sub 4} cathodes

    SciTech Connect

    McBreen, J.; Mukerjee, S.; Yang, X.Q.

    1997-05-01

    LiCoO{sub 2} cathodes are now used in most commercial lithium ion batteries. LiMn{sub 2}O{sub 4} is an attractive low cost alternative. However, it is difficult to make reproducibly. At Brookhaven National Laboratory two in situ synchrotron x-ray techniques, that are available at the National Synchrotron Light Source (NSLS), have been used to investigate LiMn{sub 2}O{sub 4}. The techniques are x-ray absorption and high resolution x-ray diffraction. With x-ray absorption it is possible to follow the changes in the Mn oxidation state and the changes in the Mn-O and Mn-Mn bond lengths on cycling. Also it is possible to detect amorphous phases. The high energy x-rays at the diffraction Beam Lines at the NSLS (up to 24 KeV) permit in situ x-ray diffraction, in the transmission mode, in thin lithium and lithium ion cells. The evolution of the structural chances that occur on cycling can be followed. These in situ measurements were done on Li/LiMn{sub 2}O{sub 4} cells with a liquid electrolyte (1 M LiPF{sub 6} in a 1:1:3 PC:EC:DMC solvent).

  19. Thickness measurement of semiconductor thin films by energy dispersive X-ray fluorescence benchtop instrumentation: Application to GaN epilayers grown by molecular beam epitaxy

    NASA Astrophysics Data System (ADS)

    Queralt, I.; Ibañez, J.; Marguí, E.; Pujol, J.

    2010-07-01

    The importance of thin films in modern high technology products, such as semiconductors, requires fast and non-destructive analysis. A methodology to determine the thickness of single layers with benchtop energy dispersive X-ray fluorescence (EDXRF) instrumentation is described and tested following analytical validation criteria. The experimental work was carried out on gallium nitride thin films epitaxially grown on sapphire substrate. The results of samples with layers in the range from 400 to 1000 nm exhibit a good correlation with the layer thickness determined by optical reflectance. Spectral data obtained using thin layered samples indicate the possibility to precisely evaluate layer thickness from 5 nm, with a low relative standard deviation (RSD < 2%) of the results. In view of the limits of optical reflectance for very thin layer determination, EDXRF analysis offers the potential for the thickness determination of such kind of samples.

  20. Effects of Pamidronate on Dental Enamel Formation Assessed by Light Microscopy, Energy-Dispersive X-Ray Analysis, Scanning Electron Microscopy, and Microhardness Testing.

    PubMed

    Soares, Ana P; do Espírito Santo, Renan F; Line, Sérgio R P; Pinto, Maria das G F; Santos, Pablo de M; Toralles, Maria Betania P; do Espírito Santo, Alexandre R

    2016-06-01

    The aim of the present work was to investigate birefringence and morphology of the secretory-stage enamel organic extracellular matrix (EOECM), and structural and mechanical properties of mature enamel of upper incisors from adult rats that had been treated with pamidronate disodium (0.5 mg/kg/week for 56 days), using transmitted polarizing and bright-field light microscopies (TPLM and BFLM), energy-dispersive X-ray (EDX) analysis, scanning electron microscopy (SEM) and microhardness testing. BFLM showed no morphological changes of the EOECM in pamidronate and control groups, but TPLM revealed a statistically significant reduction in optical retardation values of birefringence brightness of pamidronate-treated rats when compared with control animals (p0.05). The present study indicates that pamidronate can affect birefringence of the secretory-stage EOECM, which does not seem to be associated with significant changes in morphological and/or mechanical properties of mature enamel. PMID:27212049

  1. Analysis of Catalonian silver coins from the Spanish War of Independence period (1808-1814) by Energy Dispersive X-ray Fluorescence

    NASA Astrophysics Data System (ADS)

    Pitarch, A.; Queralt, I.; Alvarez-Perez, A.

    2011-02-01

    Between the years 1808 and 1814, the Spanish War of Independence took place. This period, locally known as "Guerra del Francès", generated the need for money and consequently five mints were opened around the Catalan territory. To mark the 200th anniversary of the beginning of the war, an extensive campaign of Energy Dispersive X-ray Fluorescence measurements of some of these "emergency coins" was carried out. Apart from the silver (major constituent of all the studied coins) it has been possible to recognize copper as main metal alloying element. Likewise, the presence of zinc, tin, lead, gold, platinum, antimony, nickel and iron has been also identified. The obtained results have been useful not only for the characterization of the alloys, but also to determine the differences and analogies between the emissions and for historical explanations.

  2. Atomic-Resolution X-ray Energy-Dispersive Spectroscopy Chemical Mapping of Substitutional Dy Atoms in a High-Coercivity Neodymium Magnet

    NASA Astrophysics Data System (ADS)

    Itakura, Masaru; Watanabe, Natsuki; Nishida, Minoru; Daio, Takeshi; Matsumura, Syo

    2013-05-01

    We have investigated local element distributions in a Dy-doped Nd2Fe14B hot-deformed magnet by atomic-column resolution chemical mapping using an X-ray energy-dispersive spectrometer (XEDS) attached to an aberration-corrected scanning transmission electron microscope (Cs-corrected STEM). The positions of the Nd and Dy atomic columns were visualized in the XEDS maps. The substitution of Dy was limited to a surface layer 2-3 unit cells thick in the Nd2Fe14B grains, and the Dy atoms preferentially occupied the 4f-Nd sites of Nd2Fe14B. These results provide further insights into the principal mechanism governing the coercivity enhancement due to Dy doping.

  3. Peritoneal "melanosis" associated with a ruptured ovarian dermoid cyst: report of a case with electron-probe energy dispersive X-ray analysis.

    PubMed

    Jaworski, R C; Boadle, R; Greg, J; Cocks, P

    2001-10-01

    A case of peritoneal "melanosis" due to a ruptured left ovarian dermoid cyst is described. Histology showed that the dermoid contained gastric mucosa associated with ulceration, necrosis, and hemorrhage. The areas of pigmentation within the dermoid, omentum, and peritoneal cavity were due to collections of heavily pigment-laden macrophages. The pigment lacked the histochemical features of either melanin or hemosiderin, but electron-probe energy dispersive x-ray analysis showed that the pigment contained a high concentration of iron. It is postulated that peptic ulceration with hemorrhage is the most likely source of the pigment and that the peritoneal pigmentation is secondary to spillage of the contents of the dermoid cyst. PMID:11603224

  4. Remineralization of demineralized enamel by toothpastes: a scanning electron microscopy, energy dispersive X-ray analysis, and three-dimensional stereo-micrographic study.

    PubMed

    Gjorgievska, Elizabeta S; Nicholson, John W; Slipper, Ian J; Stevanovic, Marija M

    2013-06-01

    Remineralization of hard dental tissues is thought to be a tool that could close the gap between prevention and surgical procedures in clinical dentistry. The purpose of this study was to examine the remineralizing potential of different toothpaste formulations: toothpastes containing bioactive glass, hydroxyapatite, or strontium acetate with fluoride, when applied to demineralized enamel. Results obtained by scanning electron microscopy (SEM) and SEM/energy dispersive X-ray analyses proved that the hydroxyapatite and bioactive glass-containing toothpastes were highly efficient in promoting enamel remineralization by formation of deposits and a protective layer on the surface of the demineralized enamel, whereas the toothpaste containing 8% strontium acetate and 1040 ppm fluoride as NaF had little, if any, remineralization potential. In conclusion, the treatment of demineralized teeth with toothpastes containing hydroxyapatite or bioactive glass resulted in repair of the damaged tissue. PMID:23659606

  5. On the authenticity of eight Reales 1730 Mexican silver coins by X-ray diffraction and by energy dispersion spectroscopy techniques

    NASA Astrophysics Data System (ADS)

    Rojas-Rodriguez, I.; Herrera, A.; Vázquez-López, C.; Apolo, R.; González-Hernández, J.; Hernández-Landaverde, M. A.; Rodriguez, M. E.

    2004-02-01

    Ancient silver Mexican coins made during the years 1730-1734, were analyzed non-destructively by energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and by optical microscopy. Nine coins of denomination eight Reales were studied. These coins belong to the numismatic private collection in Mexico. Six elements (copper, aluminum, magnesium, silicon, chromium and silver) were determined quantitatively. The coins reveal a uniform Ag concentration. Some of the items are covered with patina. A strong positive correlation between Al and Cu content and also a strong negative correlation between S and Ag were determined. The weight of the coins varied between 26.1344 and 26.9913 g, which is a good indicator of the authenticity of the items. The purpose of this work is to investigate by precise means if some of the coins were falsified or if really all of them are authentic.

  6. Determination of heavy metals in suspended waste water collected from Oued El Harrach Algiers River by Energy Dispersive X-Ray Fluorescence

    NASA Astrophysics Data System (ADS)

    Ouziane, S.; Amokrane, A.; Toumert, I.

    2013-12-01

    A preliminary study of the atmospheric pollution in the centre of Algiers is one of the important fields of applications in the environmental science. Nowadays, we need to evaluate the level of the contamination which has an unfavourable effect on physicochemical properties of soils and plants and namely also on human health. In the present work, water samples collected from Oued El-Harrach Algiers River, have been filtered in 0.45 μm Millipore filters to be analysed by Energy Dispersive X-Ray Fluorescence technique using 109Cd radioisotope source. Concentrations of the toxic elements like heavy metals are determined and compared with the published ones values by Yoshida [1] and those obtained using PIXE and NAA techniques [6].

  7. Liver concentrations of copper, zinc, iron and molybdenum in sheep and goats from northern Greece, determined by energy-dispersive X-ray fluorescence spectrometry.

    PubMed

    Papachristodoulou, Christina; Stamoulis, Konstantinos; Tsakos, Panagiotis; Vougidou, Christina; Vozikis, Vasileios; Papadopoulou, Chrissanthy; Ioannides, Konstantinos

    2015-04-01

    Energy-dispersive X-Ray fluorescence spectrometry was used to determine the concentrations of copper (Cu), zinc, iron and molybdenum in the liver of 76 sheep and goats from the regions of Macedonia-Thrace, northern Greece. In general, metal concentrations were in the adequate range, with one main exception of Cu-deficiency observed in all of the examined goat liver samples and Cu-toxicity found in 4 % of the sheep liver samples. One-way analysis of variance was carried out to determine significant differences among means depending on animal species, sex and age. Pearson correlation analysis was used to explore correlations between metal concentrations. The results obtained in the present study are discussed in the framework of diagnostic ranges, suggested for classifying the metal status of sheep and goats, and are compared with liver metal concentrations reported world-wide. PMID:25694162

  8. Fast elemental screening of soil and sediment profiles using small-spot energy-dispersive X-ray fluorescence: application to mining sediments geochemistry.

    PubMed

    Gonzalez-Fernandez, Oscar; Queralt, Ignacio

    2010-09-01

    Elemental analysis of different sediment cores originating from the Cartagena-La Union mining district in Spain was carried out by means of a programmable small-spot energy-dispersive X-ray fluorescence (EDXRF) spectrometer to study the distribution of heavy metals along soil profiles. Cores were obtained from upstream sediments of a mining creek, from the lowland sedimentation plain, and from a mining landfill dump (tailings pile). A programmable two-dimensional (2D) stage and a focal spot resolution of 600 μm allow us to obtain complete core mapping. Geochemical results were verified using a more powerful wavelength-dispersion X-ray fluorescence (WDXRF) technique. The data obtained was processed in order to study the statistical correlations within the elemental compositions. The results obtained allow us to observe the differential in-depth distribution of heavy metals among the sampled zones. Dump site cores exhibit a homogeneous distribution of heavy metals, whereas the alluvial plain core shows accumulation of heavy metals in the upper part. This approach can be useful for the fast screening of heavy metals in depositional environments around mining sites. PMID:20828442

  9. A standards-based method for compositional analysis by energy dispersive X-ray spectrometry using multivariate statistical analysis: application to multicomponent alloys.

    PubMed

    Rathi, Monika; Ahrenkiel, S P; Carapella, J J; Wanlass, M W

    2013-02-01

    Given an unknown multicomponent alloy, and a set of standard compounds or alloys of known composition, can one improve upon popular standards-based methods for energy dispersive X-ray (EDX) spectrometry to quantify the elemental composition of the unknown specimen? A method is presented here for determining elemental composition of alloys using transmission electron microscopy-based EDX with appropriate standards. The method begins with a discrete set of related reference standards of known composition, applies multivariate statistical analysis to those spectra, and evaluates the compositions with a linear matrix algebra method to relate the spectra to elemental composition. By using associated standards, only limited assumptions about the physical origins of the EDX spectra are needed. Spectral absorption corrections can be performed by providing an estimate of the foil thickness of one or more reference standards. The technique was applied to III-V multicomponent alloy thin films: composition and foil thickness were determined for various III-V alloys. The results were then validated by comparing with X-ray diffraction and photoluminescence analysis, demonstrating accuracy of approximately 1% in atomic fraction. PMID:23298470

  10. Alterations of the intracellular water and ion concentrations in brain and liver cells during aging as revealed by energy dispersive X-ray microanalysis of bulk specimens

    SciTech Connect

    Lustyik, G.; Nagy, I.

    1985-01-01

    Age dependence of the intracellular concentrations of monovalent ions (Na+, K+ and Cl-) was examined in 1, 11 and 25-month-old rat brain and liver cells by using energy dispersive X-ray microanalysis. The in vivo concentrations of Na+, K+ and Cl- ions were calculated from two different measurements: The elemental concentrations were measured in freeze-dried tissue pieces, and the intracellular water content was determined by means of a recently developed X-ray microanalytic method, using frozen-hydrated and fractured bulk specimens as well as subsequent freeze-drying. All the single monovalent ion concentrations and consequently, also the total monovalent ion content showed statistically significant increases during aging in brain cortical neurons. A 3-6% loss of the intracellular water content was accompanied by a 25-45% increase of the monovalent ionic strengths by the age of 25 months. A membrane protective OH radical scavenger (centrophenoxine) reversed the dehydration in the nerve cells of old animals, resulting in a decrease of the intracellular ion concentrations. Aging has a less prominent effect on the water and ion contents of the hepatocytes. The degree of water loss of cytoplasm exceeds that of the nuclei in the liver, suggesting that dominantly the translational steps can be involved in the general age altered slowing down of the protein synthetic machinery, predicted by the membrane hypothesis of aging.

  11. Performance of a gaseous detector based energy dispersive X-ray fluorescence imaging system: Analysis of human teeth treated with dental amalgam

    NASA Astrophysics Data System (ADS)

    Silva, A. L. M.; Figueroa, R.; Jaramillo, A.; Carvalho, M. L.; Veloso, J. F. C. A.

    2013-08-01

    Energy dispersive X-ray fluorescence (EDXRF) imaging systems are of great interest in many applications of different areas, once they allow us to get images of the spatial elemental distribution in the samples. The detector system used in this study is based on a micro patterned gas detector, named Micro-Hole and Strip Plate. The full field of view system, with an active area of 28 × 28 mm2 presents some important features for EDXRF imaging applications, such as a position resolution below 125 μm, an intrinsic energy resolution of about 14% full width at half maximum for 5.9 keV X-rays, and a counting rate capability of 0.5 MHz. In this work, analysis of human teeth treated by dental amalgam was performed by using the EDXRF imaging system mentioned above. The goal of the analysis is to evaluate the system capabilities in the biomedical field by measuring the drift of the major constituents of a dental amalgam, Zn and Hg, throughout the tooth structures. The elemental distribution pattern of these elements obtained during the analysis suggests diffusion of these elements from the amalgam to teeth tissues.

  12. In Situ Density Measurement of Basaltic Melts at High Pressure by X-ray Absorption Method

    NASA Astrophysics Data System (ADS)

    Ando, R.; Ohtani, E.; Suzuki, A.; Urakawa, S.; Katayama, Y.

    2004-12-01

    Density of silicate melt at high pressure is one of the most important properties to understand magma migration in the planetary interior. However, because of experimental difficulties, the density of magma at high pressure is poorly known. Katayama et al. (1996) recently developed a new in situ density measurement method for metallic melts, based on the density dependency of X-ray absorption in the sample. In this study, we tried to measure the density of basaltic melt by this absorption method. When X-ray is transmitted to the sample, the intensity of the transmitted X-ray beam (I) is expressed as follows; I=I0exp(-μ ρ t), where I0 is the intensity of incident X-ray beam, μ is the mass absorption coefficient, ρ is the density of the sample, and t is the thickness of the sample. If t and μ are known, we can determine the density of the sample by measuring I and I0. This is the principle of the absorption method for density measurement. In this study, in order to determine t, we used a single crystalline diamond cylinder as a sample capsule, diamond is less compressive and less deformable so that even at high pressure t (thickness of the sample at the point x) is expressed as follows; t = 2*(R02-x2)1/2, R0 is the inner radius of cylinder at the ambient condition, and x is distance from a center of the capsule. And diamond also shows less absorption so that this make it possible to measure the density of silicate melt with smaller absorption coefficient than metallic melts. In order to know the μ of the sample, we measured both densities (ρ ) and absorptions (I/I0) for some glasses and crystals with same composition of the sample at the ambient condition, and calculated as fallows; μ =ln(I/I0)/ρ . Experiments were made at the beamline (BL22XU) of SPring-8. For generation of high pressure and high temperature, we used DIA-type cubic anvil apparatus (SMAP180) there. We used tungsten carbide anvils with the edge-length of 6 mm. The energy of monochromatic X-ray

  13. Combination of electron energy-loss spectroscopy and energy dispersive x-ray spectroscopy to determine indium concentration in InGaN thin film structures

    NASA Astrophysics Data System (ADS)

    Wang, X.; Chauvat, M. P.; Ruterana, P.; Walther, T.

    2015-11-01

    We demonstrate a method to determine the indium concentration, x, of In x Ga1-x N thin films by combining plasmon excitation studies in electron energy-loss spectroscopy (EELS) with a novel way of quantification of the intensity of x-ray lines in energy-dispersive x-ray spectroscopy (EDXS). The plasmon peak in EELS of InGaN is relatively broad. We fitted a Lorentz function to the main plasmon peak to suppress noise and the influence from the neighboring Ga 3d transition in the spectrum, which improves the precision in the evaluation of the plasmon peak position. As the indium concentration of InGaN is difficult to control during high temperature growth due to partial In desorption, the nominal indium concentrations provided by the growers were not considered reliable. The indium concentration obtained from EDXS quantification using Oxford Instrument ISIS 300 x-ray standard quantification software often did not agree with the nominal indium concentration, and quantification using K and L lines was inconsistent. We therefore developed a self-consistent iterative procedure to determine the In content from thickness-dependent k-factors, as described in recent work submitted to Journal of Microscopy. When the plasmon peak position is plotted versus the indium concentration from EDXS we obtain a linear relationship over the whole compositional range, and the standard error from linear least-squares fitting shows that the indium concentration can be determined from the plasmon peak position to within Δx = ± 0.037 standard deviation.

  14. Thermoelectrically cooled semiconductor detectors for non-destructive analysis of works of art by means of energy dispersive X-ray fluorescence

    NASA Astrophysics Data System (ADS)

    Cesareo, Roberto; Ettore Gigante, Giovanni; Castellano, Alfredo

    1999-06-01

    Thermoelectrically cooled semiconductor detectors, such as Si-PIN, Si-drift, Cd1-xZnxTe and HgI 2, coupled to miniaturized low-power X-ray tubes, are well suited in portable systems for energy-dispersive X-ray fluorescence (EDXRF), analysis of archaeological samples. The Si-PIN detector is characterized by a thickness of about 300 μm, an area of about 2×3 mm 2, an energy resolution of about 200-250 eV at 5.9 keV and an entrance window of 25-75 μm. The Si-drift detector has approximately the same area and thickness, but an energy resolution of 155 eV at 5.9 keV. The efficiency of these detectors is around 100% from 4 to 10 keV, and then decreases versus energy, reaching ˜9% at 30 keV. Coupled to a miniaturized 10 kV, 0.1 mA, Ca-anode or to a miniaturized 30 kV, 0.1 mA, W-anode X-ray tubes, portable systems can be constructed, which are able to analyse K-lines of elements up to about silver, and L-lines of heavy elements. The Cd 1- xZn xTe detector has an area of 4 mm 2 and a thickness of 3 mm. It has an energy resolution of about 300 eV at 5.9 keV, and an efficiency of 100% over the whole range of X-rays. Finally the HgI 2 detector has an efficiency of about 100% in the whole range of X-rays, and an energy resolution of about 200 eV at 5.9 keV. Coupled to a small 50-60 kV, 1 mA, W-anode X-ray tube, portable systems can be constructed, for the analysis of practically all elements. These systems were applied to analysis in the field of archaeometry and in all applications for which portable systems are needed or at least useful (for example X-ray transmission measurements, X-ray microtomography and so on). Results of in-field use of these detectors and a comparison among these room temperature detectors in relation to concrete applications are presented. More specifically, concerning EDXRF analysis, ancient gold samples were analysed in Rome, in Mexico City and in Milan, ancient bronzes in Sassari, in Bologna, in Chieti and in Naples, and sulfur (due to pollution

  15. In Situ Ambient Pressure X-ray Photoelectron Spectroscopy Studies of Lithium-Oxygen Redox Reactions

    NASA Astrophysics Data System (ADS)

    Lu, Yi-Chun; Crumlin, Ethan J.; Veith, Gabriel M.; Harding, Jonathon R.; Mutoro, Eva; Baggetto, Loïc; Dudney, Nancy J.; Liu, Zhi; Shao-Horn, Yang

    2012-10-01

    The lack of fundamental understanding of the oxygen reduction and oxygen evolution in nonaqueous electrolytes significantly hinders the development of rechargeable lithium-air batteries. Here we employ a solid-state Li4+xTi5O12/LiPON/LixV2O5 cell and examine in situ the chemistry of Li-O2 reaction products on LixV2O5 as a function of applied voltage under ultra high vacuum (UHV) and at 500 mtorr of oxygen pressure using ambient pressure X-ray photoelectron spectroscopy (APXPS). Under UHV, lithium intercalated into LixV2O5 while molecular oxygen was reduced to form lithium peroxide on LixV2O5 in the presence of oxygen upon discharge. Interestingly, the oxidation of Li2O2 began at much lower overpotentials (~240 mV) than the charge overpotentials of conventional Li-O2 cells with aprotic electrolytes (~1000 mV). Our study provides the first evidence of reversible lithium peroxide formation and decomposition in situ on an oxide surface using a solid-state cell, and new insights into the reaction mechanism of Li-O2 chemistry.

  16. Dynamics of barite growth in porous media quantified by in situ synchrotron X-ray tomography

    NASA Astrophysics Data System (ADS)

    Godinho, jose; Gerke, kirill

    2016-04-01

    Current models used to formulate mineral sequestration strategies of dissolved contaminants in the bedrock often neglect the effect of confinement and the variation of reactive surface area with time. In this work, in situ synchrotron X-ray micro-tomography is used to quantify barite growth rates in a micro-porous structure as a function of time during 13.5 hours with a resolution of 1 μm. Additionally, the 3D porous network at different time frames are used to simulate the flow velocities and calculate the permeability evolution during the experiment. The kinetics of barite growth under porous confinement is compared with the kinetics of barite growth on free surfaces in the same fluid composition. Results are discussed in terms of surface area normalization and the evolution of flow velocities as crystals fill the porous structure. During the initial hours the growth rate measured in porous media is similar to the growth rate on free surfaces. However, as the thinner flow paths clog the growth rate progressively decreases, which is correlated to a decrease of local flow velocity. The largest pores remain open, enabling growth to continue throughout the structure. Quantifying the dynamics of mineral precipitation kinetics in situ in 4D, has revealed the importance of using a time dependent reactive surface area and accounting for the local properties of the porous network, when formulating predictive models of mineral precipitation in porous media.

  17. Oxidation Induced Doping of Nanoparticles Revealed by in Situ X-ray Absorption Studies.

    PubMed

    Kwon, Soon Gu; Chattopadhyay, Soma; Koo, Bonil; Dos Santos Claro, Paula Cecilia; Shibata, Tomohiro; Requejo, Félix G; Giovanetti, Lisandro J; Liu, Yuzi; Johnson, Christopher; Prakapenka, Vitali; Lee, Byeongdu; Shevchenko, Elena V

    2016-06-01

    Doping is a well-known approach to modulate the electronic and optical properties of nanoparticles (NPs). However, doping at nanoscale is still very challenging, and the reasons for that are not well understood. We studied the formation and doping process of iron and iron oxide NPs in real time by in situ synchrotron X-ray absorption spectroscopy. Our study revealed that the mass flow of the iron triggered by oxidation is responsible for the internalization of the dopant (molybdenum) adsorbed at the surface of the host iron NPs. The oxidation induced doping allows controlling the doping levels by varying the amount of dopant precursor. Our in situ studies also revealed that the dopant precursor substantially changes the reaction kinetics of formation of iron and iron oxide NPs. Thus, in the presence of dopant precursor we observed significantly faster decomposition rate of iron precursors and substantially higher stability of iron NPs against oxidation. The same doping mechanism and higher stability of host metal NPs against oxidation was observed for cobalt-based systems. Since the internalization of the adsorbed dopant at the surface of the host NPs is driven by the mass transport of the host, this mechanism can be potentially applied to introduce dopants into different oxidized forms of metal and metal alloy NPs providing the extra degree of compositional control in material design. PMID:27152970

  18. In Situ Ambient Pressure X-ray Photoelectron Spectroscopy Studies of Lithium-Oxygen Redox Reactions

    PubMed Central

    Lu, Yi-Chun; Crumlin, Ethan J.; Veith, Gabriel M.; Harding, Jonathon R.; Mutoro, Eva; Baggetto, Loïc; Dudney, Nancy J.; Liu, Zhi; Shao-Horn, Yang

    2012-01-01

    The lack of fundamental understanding of the oxygen reduction and oxygen evolution in nonaqueous electrolytes significantly hinders the development of rechargeable lithium-air batteries. Here we employ a solid-state Li4+xTi5O12/LiPON/LixV2O5 cell and examine in situ the chemistry of Li-O2 reaction products on LixV2O5 as a function of applied voltage under ultra high vacuum (UHV) and at 500 mtorr of oxygen pressure using ambient pressure X-ray photoelectron spectroscopy (APXPS). Under UHV, lithium intercalated into LixV2O5 while molecular oxygen was reduced to form lithium peroxide on LixV2O5 in the presence of oxygen upon discharge. Interestingly, the oxidation of Li2O2 began at much lower overpotentials (~240 mV) than the charge overpotentials of conventional Li-O2 cells with aprotic electrolytes (~1000 mV). Our study provides the first evidence of reversible lithium peroxide formation and decomposition in situ on an oxide surface using a solid-state cell, and new insights into the reaction mechanism of Li-O2 chemistry. PMID:23056907

  19. In situ ambient pressure X-ray photoelectron spectroscopy studies of lithium-oxygen redox reactions.

    PubMed

    Lu, Yi-Chun; Crumlin, Ethan J; Veith, Gabriel M; Harding, Jonathon R; Mutoro, Eva; Baggetto, Loïc; Dudney, Nancy J; Liu, Zhi; Shao-Horn, Yang

    2012-01-01

    The lack of fundamental understanding of the oxygen reduction and oxygen evolution in nonaqueous electrolytes significantly hinders the development of rechargeable lithium-air batteries. Here we employ a solid-state Li(4+x)Ti(5)O(12)/LiPON/Li(x)V(2)O(5) cell and examine in situ the chemistry of Li-O(2) reaction products on Li(x)V(2)O(5) as a function of applied voltage under ultra high vacuum (UHV) and at 500 mtorr of oxygen pressure using ambient pressure X-ray photoelectron spectroscopy (APXPS). Under UHV, lithium intercalated into Li(x)V(2)O(5) while molecular oxygen was reduced to form lithium peroxide on Li(x)V(2)O(5) in the presence of oxygen upon discharge. Interestingly, the oxidation of Li(2)O(2) began at much lower overpotentials (~240 mV) than the charge overpotentials of conventional Li-O(2) cells with aprotic electrolytes (~1000 mV). Our study provides the first evidence of reversible lithium peroxide formation and decomposition in situ on an oxide surface using a solid-state cell, and new insights into the reaction mechanism of Li-O(2) chemistry. PMID:23056907

  20. Data of low-dose phase-based X-ray imaging for in situ soft tissue engineering assessments.

    PubMed

    Izadifar, Zohreh; Honaramooz, Ali; Wiebe, Sheldon; Belev, George; Chen, Xiongbiao; Chapman, Dean

    2016-03-01

    This article presents the data of using three phase-based X-ray imaging techniques to characterize biomaterial scaffold and soft tissues in situ, as reported in our study "Low-dose phase-based X-ray imaging techniques for in situ soft tissue engineering assessments" [1]. The examined parameters include the radiation dose, scan time, and image quality, which are all critical to longitudinal in situ live animal assessments. The data presented were obtained from three dimensional imaging of scaffolds in situ cartilage by means of synchrotron-based computed tomography-diffraction enhanced imaging (CT-DEI), analyzer based imaging (CT-ABI), and in-line phase contrast imaging (CT-PCI) at standard and low dose imaging modalities. PMID:26909381

  1. Data of low-dose phase-based X-ray imaging for in situ soft tissue engineering assessments

    PubMed Central

    Izadifar, Zohreh; Honaramooz, Ali; Wiebe, Sheldon; Belev, George; Chen, Xiongbiao; Chapman, Dean

    2016-01-01

    This article presents the data of using three phase-based X-ray imaging techniques to characterize biomaterial scaffold and soft tissues in situ, as reported in our study “Low-dose phase-based X-ray imaging techniques for in situ soft tissue engineering assessments” [1]. The examined parameters include the radiation dose, scan time, and image quality, which are all critical to longitudinal in situ live animal assessments. The data presented were obtained from three dimensional imaging of scaffolds in situ cartilage by means of synchrotron-based computed tomography-diffraction enhanced imaging (CT-DEI), analyzer based imaging (CT-ABI), and in-line phase contrast imaging (CT-PCI) at standard and low dose imaging modalities. PMID:26909381

  2. In-situ non-ambient X-ray diffraction studies of indium tungstate

    SciTech Connect

    Baiz, Tamam I.; Heinrich, Christophe P.; Banek, Nathan A.; Vivekens, Boris L.; Lind, Cora

    2012-03-15

    In situ variable temperature and high pressure X-ray diffraction studies were carried out on indium tungstate (In{sub 2}W{sub 3}O{sub 12}). This material displays positive volume expansion in both its low temperature monoclinic and high temperature orthorhombic phases, with negative thermal expansion along the a axis and positive thermal expansion along the b and c axes. Upon hydrostatic compression in a diamond anvil cell, one crystalline to crystalline phase transition is observed in the range 1.9 to 2.7 GPa, and progressive irreversible amorphization occurs at pressures above 4.3 GPa. The crystalline high pressure phase appears to be isostructural to previously observed high pressure phases in other A{sub 2}M{sub 3}O{sub 12} compounds. - Graphical abstract: Variable pressure X-ray diffraction patterns of In{sub 2}W{sub 3}O{sub 12} collected in a diamond anvil cell. A phase transition is clearly observed between 2.2 and 2.7 GPa, followed by irreversible amorphization. Highlights: Black-Right-Pointing-Pointer The structure of In{sub 2}W{sub 3}O{sub 12} was studied as a function of temperature and pressure. Black-Right-Pointing-Pointer Uniaxial negative thermal expansion was observed above 250 Degree-Sign C. Black-Right-Pointing-Pointer A pressure-induced phase transition occurred between 2.2 and 2.7 GPa. Black-Right-Pointing-Pointer Pressure-induced irreversible amorphization was observed above 4.3 GPa.

  3. High-pressure behavior and thermoelastic properties of niobium studied by in situ x-ray diffraction

    SciTech Connect

    Zou, Yongtao E-mail: yongtaozou6@gmail.com; Li, Baosheng; Qi, Xintong; Wang, Xuebing; Chen, Ting; Li, Xuefei; Welch, David

    2014-07-07

    In situ synchrotron energy dispersive x-ray diffraction (XRD) experiments on Nb have been conducted at pressures up to 6.4 GPa and temperatures up to 1073 K. From the pressure-volume-temperature measurements, thermoelastic parameters were derived for the first time for Nb based on the thermal pressure (ΔP{sub th}) equation of state (EOS), modified high-T Birch-Murnaghan EOS, and Mie-Grüneisen-Debye EOS. With the pressure derivative of the bulk modulus K{sub T}{sup ´} fixed at 4.0, we obtained the ambient isothermal bulk modulus K{sub T0}=174(5) GPa, the temperature derivative of bulk modulus at constant pressure (∂K{sub T}/∂T){sub P}=-0.060(8) GPa K⁻¹ and at constant volume (∂K{sub T}/∂T){sub V}=-0.046(8) GPa K⁻¹, the volumetric thermal expansivity α{sub T}(T)=2.3(3)×10⁻⁵+0.3(2)×10⁻⁸T (K⁻¹), as well as the pressure dependence of thermal expansion (∂α/∂P){sub T}=(₋2.0±0.4)×10⁻⁶ K⁻¹ GPa⁻¹. Fitting the present data to the Mie-Grüneisen-Debye EOS with Debye temperature Θ₀=276.6 K gives γ₀=1.27(8) and K{sub T0}=171(3) GPa at a fixed value of q=3.0. The ambient isothermal bulk modulus and Grüneisen parameter derived from this work are comparable to previously reported values from both experimental and theoretical studies. An in situ high-resolution, angle dispersive XRD study on Nb did not indicate any anomalous behavior related to pressure-induced electronic topological transitions at ~5 GPa as has been reported previously.

  4. An in situ XAFS study--the formation mechanism of gold nanoparticles from X-ray-irradiated ionic liquid.

    PubMed

    Ma, Jingyuan; Zou, Yang; Jiang, Zheng; Huang, Wei; Li, Jiong; Wu, Guozhong; Huang, Yuying; Xu, Hongjie

    2013-07-28

    An in situ X-ray absorption fine structure (XAFS) experiment has been performed to observe the evolution of gold nanoparticles in the ionic liquid [BMIM][AuCl4], by hard X-ray irradiation. The ionic liquid acts as both a reducing agent and a protective ligand. A synchrotron-based X-ray plays the role of the irradiation source, which induces the reduction of the gold species, as well as being a real time probe for XAFS measurements. From the extended X-ray absorption fine structure (EXAFS) fitting results for a series of spectra of gold L3-edge, it can be seen clearly that there is a single Au-Cl bond breaking process before the formation of Au-Au bonds, which is different from previous reports on the formation of Au nanoparticles by several chemical methods. PMID:23765109

  5. Synchrotron X-Ray Microprobe In-Situ Analysis of Extraterrestrial Particles Collected in Aerogel on the MIR Space Station

    NASA Technical Reports Server (NTRS)

    Flynn, G. J.; Sutton, S. R.; Horz, F.

    2000-01-01

    Using in-situ x-ray fluorescence, we determined the Cr/Fe, Mn/Fe and Ni/Fe of a particle captured in aerogel on MIR are approximately chondritic, indicating an extraterrestrial origin. Impurity of the aerogel precluded determining the Cu and Zn.

  6. In Situ X-ray Diffraction Studies of Cathode Materials in Lithium Batteries

    SciTech Connect

    Yang, X. Q.; Sun, X.; McBreen, J.; Mukerjee, S.; Gao, Yuan; Yakovleva, M. V.; Xing, X. K.; Daroux, M. L.

    1998-11-01

    system definitely requires an in situ XRD technique to study the detail structural changes of the system during charge and discharge. The in situ XRD technique was used by Reimers, Li,and Dahn to study the LiCoO{sub 2}, LiNiO{sub 2}, and LiMn{sub 2}O{sub 4} systems. Their results of these studies have demonstrated that in situ XRD can provide more detailed information about the cathode material structural changes during charge-discharge. Conventional x-ray sources were used in these studies and the beryllium windows were used in the in situ cells. Provisions were made to prevent corrosion of the beryllium windows during charge-discharge. For this reason, the in situ cells were often designed quite differently than a real battery. More seriously, the problem of beryllium corrosion restricted the voltage range of the cell below 4.5 V. This limited the use of this technique to study the effects of overcharge which is very important to the thermal stability of the cathodes. Using the plastic lithium battery technology, Amatucci, Tarascon, and Klein constructed an in situ XRD cell, which allows structural investigations at voltages greater than 5 V without any beryllium window corrosion. However, all of these in situ XRD studies using conventional x-ray sources probe the cell in reflection geometry. Therefore, the observed structural changes are predominantly from the top few microns of the electrode coating, which might not be representative for the whole coating during charge-discharge especially when the rate is high.

  7. Non-destructive in situ study of "Mad Meg" by Pieter Bruegel the Elder using mobile X-ray fluorescence, X-ray diffraction and Raman spectrometers

    NASA Astrophysics Data System (ADS)

    Van de Voorde, Lien; Van Pevenage, Jolien; De Langhe, Kaat; De Wolf, Robin; Vekemans, Bart; Vincze, Laszlo; Vandenabeele, Peter; Martens, Maximiliaan P. J.

    2014-07-01

    "Mad Meg", a figure of Flemish folklore, is the subject of a famous oil-on-panel painting by the Flemish renaissance artist Pieter Bruegel the Elder, exhibited in the Museum Mayer van den Bergh (Antwerp, Belgium). This article reports on the in situ chemical characterization of this masterpiece by using currently available state-of-the-art portable analytical instruments. The applied non-destructive analytical approach involved the use of a) handheld X-ray fluorescence instrumentation for retrieving elemental information and b) portable X-ray fluorescence/X-ray diffraction instrumentation and laser-based Raman spectrometers for obtaining structural/molecular information. Next to material characterization of the used pigments and of the different preparation layers of the painting, also the verification of two important historical iconographic hypotheses is performed concerning the economic way of painting by Brueghel, and whether or not he used blue smalt pigment for painting the boat that appears towards the top of the painting. The pigments identified are smalt pigment (65% SiO2 + 15% K2O + 10% CoO + 5% Al2O3) for the blue color present in all blue areas of the painting, probably copper resinate for the green colors, vermillion (HgS) as red pigment and lead white is used to form different colors. The comparison of blue pigments used on different areas of the painting gives no differences in the elemental fingerprint which confirms the existing hypothesis concerning the economic painting method by Bruegel.

  8. Single-pulse x-ray diffraction using polycapillary optics for in situ dynamic diffraction.

    PubMed

    Maddox, B R; Akin, M C; Teruya, A; Hunt, D; Hahn, D; Cradick, J; Morgan, D V

    2016-08-01

    Diagnostic use of single-pulse x-ray diffraction (XRD) at pulsed power facilities can be challenging due to factors such as the high flux and brightness requirements for diffraction and the geometric constraints of experimental platforms. By necessity, the x-ray source is usually positioned very close, within a few inches of the sample. On dynamic compression platforms, this puts the x-ray source in the debris field. We coupled x-ray polycapillary optics to a single-shot needle-and-washer x-ray diode source using a laser-based alignment scheme to obtain high-quality x-ray diffraction using a single 16 ns x-ray pulse with the source >1 m from the sample. The system was tested on a Mo sample in reflection geometry using 17 keV x-rays from a Mo anode. We also identified an anode conditioning effect that increased the x-ray intensity by 180%. Quantitative measurements of the x-ray focal spot produced by the polycapillary yielded a total x-ray flux on the sample of 3.3 ± 0.5 × 10(7) molybdenum Kα photons. PMID:27587130

  9. Rapid thermal processing chamber for in-situ x-ray diffraction.

    PubMed

    Ahmad, Md Imteyaz; Van Campen, Douglas G; Fields, Jeremy D; Yu, Jiafan; Pool, Vanessa L; Parilla, Philip A; Ginley, David S; Van Hest, Maikel F A M; Toney, Michael F

    2015-01-01

    Rapid thermal processing (RTP) is widely used for processing a variety of materials, including electronics and photovoltaics. Presently, optimization of RTP is done primarily based on ex-situ studies. As a consequence, the precise reaction pathways and phase progression during the RTP remain unclear. More awareness of the reaction pathways would better enable process optimization and foster increased adoption of RTP, which offers numerous advantages for synthesis of a broad range of materials systems. To achieve this, we have designed and developed a RTP instrument that enables real-time collection of X-ray diffraction data with intervals as short as 100 ms, while heating with ramp rates up to 100 °Cs(-1), and with a maximum operating temperature of 1200 °C. The system is portable and can be installed on a synchrotron beamline. The unique capabilities of this instrument are demonstrated with in-situ characterization of a Bi2O3-SiO2 glass frit obtained during heating with ramp rates 5 °C s(-1) and 100 °C s(-1), revealing numerous phase changes. PMID:25638092

  10. Rapid thermal processing chamber for in-situ x-ray diffraction

    NASA Astrophysics Data System (ADS)

    Ahmad, Md. Imteyaz; Van Campen, Douglas G.; Fields, Jeremy D.; Yu, Jiafan; Pool, Vanessa L.; Parilla, Philip A.; Ginley, David S.; Van Hest, Maikel F. A. M.; Toney, Michael F.

    2015-01-01

    Rapid thermal processing (RTP) is widely used for processing a variety of materials, including electronics and photovoltaics. Presently, optimization of RTP is done primarily based on ex-situ studies. As a consequence, the precise reaction pathways and phase progression during the RTP remain unclear. More awareness of the reaction pathways would better enable process optimization and foster increased adoption of RTP, which offers numerous advantages for synthesis of a broad range of materials systems. To achieve this, we have designed and developed a RTP instrument that enables real-time collection of X-ray diffraction data with intervals as short as 100 ms, while heating with ramp rates up to 100 °Cs-1, and with a maximum operating temperature of 1200 °C. The system is portable and can be installed on a synchrotron beamline. The unique capabilities of this instrument are demonstrated with in-situ characterization of a Bi2O3-SiO2 glass frit obtained during heating with ramp rates 5 °C s-1 and 100 °C s-1, revealing numerous phase changes.

  11. Shock Melting of Forsterite by In-Situ X-Ray Diffraction

    NASA Astrophysics Data System (ADS)

    Newman, M.; Kraus, R. G.; Wicks, J. K.; Coppari, F.; Smith, R.; Duffy, T. S.

    2015-12-01

    The equation of state of magnesium silicates at pressures and temperatures near the solid-liquid coexistence curve is important for understanding the thermal evolution and interior structure of rocky planets. Here, we present a series of laser driven shock-melt experiments on single crystal Mg_2SiO_4 forsterite, conducted at the Omega EP laser facility. Particle velocities in the Mg_2SiO_4 samples were measured using a line VISAR and used to infer the thermodynamic state of the shocked samples. In situ X-ray diffraction measurements are used to probe the melting transition and investigate the potential decomposition of Mg_2SiO_4 in to MgO and MgSiO_3 upon melt. This work examines potential kinetic effects of decomposition due to the short time scale of laser-shock experiments. In addition, the thermodynamic data collected in these experiments adds to a limited body of information regarding the equation of state of Mg_2SiO_4, which is the dominant end member composition in Earth's upper mantle. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  12. Hydrazine reduction of transition metal oxides - In situ characterization using X-ray photoelectron spectroscopy

    NASA Technical Reports Server (NTRS)

    Littrell, D. M.; Tatarchuk, B. J.

    1986-01-01

    The transition metal oxides (TMOs) V2O5, FeO3, Co3O4, NiO, CuO, and ZnO were exposed to hydrazine at various pressures. The metallic surfaces were surveyed by in situ X-ray photoelectron spectroscopy to determine the irrelative rate of reduction by hydrazine. The most easily reducible oxide, CuO, could be reduced to the metallic state at room temperature and 10 to the -6th torr. The reaction is first order with respect to CuO, with an activation energy of about 35 kJ/mol. Two types of adsorption were seen to occur at 295 K: (1) a reversible component in which the measured N:Cu ratio increased to 0.60 at hydrazine pressures up to 0.5 torr, and (2) an irreversible component, with a N:Cu ratio of 0.28, which could not be removed by extended vacuum pumping. The results of this study are useful for the identification of TMO's that can be used as solid neatallizers of hydrazine spills, and for the preparation of metal surfaces for electroplating and evaporative thin-film coating.

  13. Versatile in situ powder X-ray diffraction cells for solid–gas investigations

    PubMed Central

    Jensen, Torben R.; Nielsen, Thomas K.; Filinchuk, Yaroslav; Jørgensen, Jens-Erik; Cerenius, Yngve; Gray, Evan MacA.; Webb, Colin J.

    2010-01-01

    This paper describes new sample cells and techniques for in situ powder X-ray diffraction specifically designed for gas absorption studies up to ca 300 bar (1 bar = 100 000 Pa) gas pressure. The cells are for multipurpose use, in particular the study of solid–gas reactions in dosing or flow mode, but can also handle samples involved in solid–liquid–gas studies. The sample can be loaded into a single-crystal sapphire (Al2O3) capillary, or a quartz (SiO2) capillary closed at one end. The advantages of a sapphire single-crystal cell with regard to rapid pressure cycling are discussed, and burst pressures are calculated and measured to be ∼300 bar. An alternative and simpler cell based on a thin-walled silicate or quartz glass capillary, connected to a gas source via a VCR fitting, enables studies up to ∼100 bar. Advantages of the two cell types are compared and their applications are illustrated by case studies. PMID:22477780

  14. Kinetics of methane hydrate decomposition studied via in situ low temperature X-ray powder diffraction.

    PubMed

    Everett, S Michelle; Rawn, Claudia J; Keffer, David J; Mull, Derek L; Payzant, E Andrew; Phelps, Tommy J

    2013-05-01

    Gas hydrate is known to have a slowed decomposition rate at ambient pressure and temperatures below the melting point of ice. As hydrate exothermically decomposes, gas is released and water of the clathrate cages transforms into ice. Based on results from the decomposition of three nominally similar methane hydrate samples, the kinetics of two regions, 180-200 and 230-260 K, within the overall decomposition range 140-260 K, were studied by in situ low temperature X-ray powder diffraction. The kinetic rate constants, k(a), and the reaction mechanisms, n, for ice formation from methane hydrate were determined by the Avrami model within each region, and activation energies, E(a), were determined by the Arrhenius plot. E(a) determined from the data for 180-200 K was 42 kJ/mol and for 230-260 K was 22 kJ/mol. The higher E(a) in the colder temperature range was attributed to a difference in the microstructure of ice between the two regions. PMID:23557375

  15. In situ alkali-silica reaction observed by x-ray microscopy

    SciTech Connect

    Kurtis, K.E.; Monteiro, P.J.M.; Brown, J.T.; Meyer-Ilse, W.

    1997-04-01

    In concrete, alkali metal ions and hydroxyl ions contributed by the cement and reactive silicates present in aggregate can participate in a destructive alkali-silica reaction (ASR). This reaction of the alkalis with the silicates produces a gel that tends to imbibe water found in the concrete pores, leading to swelling of the gel and eventual cracking of the affected concrete member. Over 104 cases of alkali-aggregate reaction in dams and spillways have been reported around the world. At present, no method exists to arrest the expansive chemical reaction which generates significant distress in the affected structures. Most existing techniques available for the examination of concrete microstructure, including ASR products, demand that samples be dried and exposed to high pressure during the observation period. These sample preparation requirements present a major disadvantage for the study of alkali-silica reaction. Given the nature of the reaction and the affect of water on its products, it is likely that the removal of water will affect the morphology, creating artifacts in the sample. The purpose of this research is to observe and characterize the alkali-silica reaction, including each of the specific reactions identified previously, in situ without introducing sample artifacts. For observation of unconditioned samples, x-ray microscopy offers an opportunity for such an examination of the alkali-silica reaction. Currently, this investigation is focusing on the effect of calcium ions on the alkali-silica reaction.

  16. Boron phosphide under pressure: In situ study by Raman scattering and X-ray diffraction

    SciTech Connect

    Solozhenko, Vladimir L.; Kurakevych, Oleksandr O.; Le Godec, Yann; Kurnosov, Aleksandr V.; Oganov, Artem R.

    2014-07-21

    Cubic boron phosphide, BP, has been studied in situ by X-ray diffraction and Raman scattering up to 55 GPa at 300 K in a diamond anvil cell. The bulk modulus of B{sub 0} = 174(2) GPa has been established, which is in excellent agreement with our ab initio calculations. The data on Raman shift as a function of pressure, combined with equation-of-state (EOS) data, allowed us to estimate the Grüneisen parameters of the TO and LO modes of zinc-blende structure, γ{sub G}{sup TO }= 1.26 and γ{sub G}{sup LO }= 1.13, just like in the case of other A{sup III}B{sup V} diamond-like phases, for which γ{sub G}{sup TO }> γ{sub G}{sup LO }≅ 1. We also established that the pressure dependence of the effective electro-optical constant α is responsible for a strong change in relative intensities of the TO and LO modes from I{sub TO}/I{sub LO} ∼ 0.25 at 0.1 MPa to I{sub TO}/I{sub LO} ∼ 2.5 at 45 GPa, for which we also find excellent agreement between experiment and theory.

  17. Hybrid X-ray and γ-ray spectrometer for in-situ planetary science missions

    NASA Astrophysics Data System (ADS)

    Skidmore, M. S.; Ambrosi, R. M.; Simon, H.

    2009-06-01

    γ-Ray spectroscopy, X-ray spectroscopy and γ-ray backscatter densitometry for planetary science applications are three complementary analytical techniques that can be used to determine surface and sub-surface composition, constrain heat flow through a planetary regolith and hence understand more about the processes that formed planetary bodies. Evaluating different detector types and configurations in order to achieve these scientific objectives is a key enabling step for a successful flight instrument development programme. In this study, we evaluate and compare different detector solutions and configurations including: planar and hemispherical CdTe, a CsI(Tl) scintillator, a LaBr3(Ce) scintillator and a HPGe detector. The LaBr3(Ce) detector was chosen as the most suitable detector for an in-situ planetary science mission due to its high-radiation tolerance, low mass compared with HPGe detector systems, its comparable resolution (˜3.4% at 662 keV) to compound semiconductors (planar CdTe ˜2.4% at 662 keV) and high efficiency.

  18. Rapid terrestrial core formation from in situ X-ray computed microtomography

    NASA Astrophysics Data System (ADS)

    Chen, B.; Zhang, D.; Leng, W.; Jackson, J. M.; Wang, Y.; Yu, T.; Liu, J.; Li, J.

    2011-12-01

    The timescale of the terrestrial core formation constrained from the hafnium-tungsten chronometer is within 30 million years after the Solar System formation (e.g. Kleine et al., 2002; Yin et al., 2002). Possible mechanisms for core formation include diapiric instability of iron-rich liquids and percolation of the liquids through the solid silicate matrix. Core-mantle segregation by diapiric instabilities is thought to be a more rapid and efficient core formation process compared with percolation (Stevenson, 1981; Rubie et al., 2007; Golabek et al., 2008). Our experimental results from in situ X-ray computed microtomography show that at 1-1.5 GPa the iron-sulfur and iron-carbon liquids sank through the underlying olivine layer at a speed consistent with the measured core formation timescale. Our three-dimensional tomography data taken at various heating stages revealed that the iron-rich liquid diapirs in olivine induced percolative flow channeling processes, which affects the rheology of olivine and thus facilitates the sinking of iron-rich diapirs. Numerical simulations of diapir sinking based on the tomography observations suggest that the percolative flow channeling process accompanying the iron diapirs could significantly reduce the time for core formation segregation by a factor of 2 or more, depending on the viscosity reduction ratio caused by the percolative flow. Our study sheds new light on core formation processes in the Earth and terrestrial-like planetary bodies, contributing to our understanding of the origin and dynamics of planetary cores.

  19. Characterization of individual submicrometer aerosol particles collected in Incheon, Korea, by quantitative transmission electron microscopy energy-dispersive X-ray spectrometry

    NASA Astrophysics Data System (ADS)

    Geng, Hong; Kang, Sujin; Jung, Hae-Jin; ChoëL, Marie; Kim, Hyekyeong; Ro, Chul-Un

    2010-08-01

    For the last decade the Monte Carlo calculation method has been proven to be an excellent tool for accurately simulating electron-solid interactions in atmospheric individual particles of micrometer size. Although it was designed for application to scanning electron microscopy, in the present study it is demonstrated that the Monte Carlo calculation can also be applied in a quantitative single particle analysis using transmission electron microscopy (TEM) with an ultrathin window energy-dispersive X-ray (EDX) spectrometer with a high accelerating voltage (200 kV). By utilizing an iterative reverse Monte Carlo simulation combined with successive approximation, atomic elemental concentrations (including low-Z elements) of submicrometer standard particles were determined with high accuracy for electron beam refractory particles such as NaCl, KCl, SiO2, Fe2O3, Na2SO4, K2SO4, CaCO3, and CaSO4. On the basis of quantitative X-ray analysis together with morphological information from TEM images, overall 1638 submicrometer individual particles from 10 sets of aerosol samples collected in Incheon, Korea, were identified. The most frequently encountered particle types are carbonaceous and (NH4)2SO4/NH4HSO4-containing particles, followed by mineral (e.g., aluminosilicate, SiO2, CaCO3), sea salt, K-rich (e.g., K2SO4 and KCl), Fe-rich, fly ash, and transition or heavy-metal-containing (e.g., ZnSO4, ZnCl2, PbSO4) particles. The relative abundances of the submicrometer particle types vary among samples collected in different seasons and also depend on different air mass transport routes. This study demonstrates that the quantitative TEM-EDX individual particle analysis is a useful and reliable technique in characterizing urban submicrometer aerosol particles.

  20. Determination of inorganic nutrients in wheat flour by laser-induced breakdown spectroscopy and energy dispersive X-ray fluorescence spectrometry

    NASA Astrophysics Data System (ADS)

    Peruchi, Lidiane Cristina; Nunes, Lidiane Cristina; de Carvalho, Gabriel Gustinelli Arantes; Guerra, Marcelo Braga Bueno; de Almeida, Eduardo; Rufini, Iolanda Aparecida; Santos, Dário; Krug, Francisco José

    2014-10-01

    Laser-induced breakdown spectroscopy (LIBS) and energy dispersive X-ray fluorescence spectrometry (EDXRF) were evaluated for the determination of P, K, Ca, Mg, S, Fe, Cu, Mn and Zn in pressed pellets of wheat flours. EDXRF and LIBS calibration models were built with analytes mass fractions determined by inductively coupled plasma optical emission spectrometry after microwave-assisted acid digestion in a set of 25 wheat flour laboratory samples. Test samples consisted of pressed pellets prepared from wheat flour mixed with 30% mm- 1 cellulose binder. Experiments were carried out with a LIBS setup consisted of a Q-switched Nd:YAG laser and a spectrometer with Echelle optics and ICCD, and a benchtop EDXRF system fitted with a Rh target X-ray tube and a Si(Li) semiconductor detector. The correlation coefficients from the linear calibration models of P, K, Ca, Mg, S, Fe, Mn and Zn determined by LIBS and/or EDXRF varied from 0.9705 for Zn to 0.9990 for Mg by LIBS, and from 0.9306 for S to 0.9974 for K by EDXRF. The coefficients of variation of measurements varied from 1.2 to 20% for LIBS, and from 0.3 to 24% for EDXRF. The predictive capabilities based on RMSEP (root mean square error of prediction) values were appropriate for the determination of P, Ca, Mg, Fe, Mn and Zn by LIBS, and for P, K, S, Ca, Fe, and Zn by EDXRF. In general, results from the analysis of NIST SRM 1567a Wheat flour by LIBS and EDXRF were in agreement with their certified mass fractions.

  1. In situ analysis of elemental depth distributions in thin films by combined evaluation of synchrotron x-ray fluorescence and diffraction

    SciTech Connect

    Mainz, R.; Klenk, R.

    2011-06-15

    In this work we present a method for the in situ analysis of elemental depth distributions in thin films using a combined evaluation of synchrotron x-ray fluorescence and energy-dispersive x-ray diffraction signals. We recorded diffraction and fluorescence signals simultaneously during the reactive annealing of thin films. By means of the observed diffraction signals, the time evolution of phases in the thin films during the annealing processes can be determined. We utilized this phase information to parameterize the depth distributions of the elements in the films. The time-dependent fluorescence signals were then taken to determine the parameters representing the parameterized depth distributions. For this latter step, we numerically calculated the fluorescence intensities for a given set of depth distributions. These calculations handle polychromatic excitation and arbitrary functions of depth distributions and take into account primary and secondary fluorescence. Influences of lateral non-uniformities of the films, as well as the accuracy limits of the method, are investigated. We apply the introduced method to analyze the evolution of elemental depth distributions and to quantify the kinetic parameters during a synthesis process of CuInS{sub 2} thin films via the reactive annealing of Cu-In precursors in a sulfur atmosphere.

  2. Paper-based diffusive gradients in thin films technique coupled to energy dispersive X-ray fluorescence spectrometry for the determination of labile Mn, Co, Ni, Cu, Zn and Pb in river water

    NASA Astrophysics Data System (ADS)

    Almeida, Eduardo de; Nascimento Filho, Virgílio Franco do; Menegário, Amauri Antonio

    2012-05-01

    The diffusive gradients in thin films (DGT) technique has shown enormous potential for labile metal monitoring in fresh water due to the preconcentration, time-integrated, matrix interference removal and speciation analytical features. In this work, the coupling of energy dispersive X-ray fluorescence (EDXRF) with paper-based DGT devices was evaluated for the direct determination of Mn, Co, Ni, Cu, Zn and Pb in fresh water. The DGT samplers were assembled with cellulose (Whatman 3 MM chromatography paper) as the diffusion layer and a cellulose phosphate ion exchange membrane (Whatman P 81 paper) as the binding agent. The diffusion coefficients of the analytes on 3 MM chromatography paper were calculated by deploying the DGT samplers in synthetic solutions containing 500 μg L- 1 of Mn, Co, Ni, Cu, Zn and Pb (4 L at pH 5.5 and ionic strength at 0.05 mol L- 1). After retrieval, the DGT units were disassembled and the P 81 papers were dried and analysed by EDXRF directly. The 3 MM chromatographic paper diffusion coefficients of the analytes ranged from 1.67 to 1.87 × 10- 6 cm2 s- 1. The metal retention and phosphate group homogeneities on the P 81 membrane was studied by a spot analysis with a diameter of 1 mm. The proposed approach (DGT-EDXRF coupling) was applied to determine the analytes at five sampling sites (48 h in situ deployment) on the Piracicaba river basin, and the results (labile fraction) were compared with 0.45 μm dissolved fractions determined by synchrotron radiation-excited total reflection X-ray fluorescence (SR-TXRF). The limits of detection of DGT-EDXRF coupling for the analytes (from 7.5 to 26 μg L- 1) were similar to those obtained by the sensitive SR-TXRF technique (3.8 to 9.1 μg L- 1).

  3. Distinct charge dynamics in battery electrodes revealed by in situ and operando soft X-ray spectroscopy

    PubMed Central

    Liu, Xiaosong; Wang, Dongdong; Liu, Gao; Srinivasan, Venkat; Liu, Zhi; Hussain, Zahid; Yang, Wanli

    2013-01-01

    Developing high-performance batteries relies on material breakthroughs. During the past few years, various in situ characterization tools have been developed and have become indispensible in studying and the eventual optimization of battery materials. However, soft X-ray spectroscopy, one of the most sensitive probes of electronic states, has been mainly limited to ex situ experiments for battery research. Here we achieve in situ and operando soft X-ray absorption spectroscopy of lithium-ion battery cathodes. Taking advantage of the elemental, chemical and surface sensitivities of soft X-rays, we discover distinct lithium-ion and electron dynamics in Li(Co1/3Ni1/3Mn1/3)O2 and LiFePO4 cathodes in polymer electrolytes. The contrast between the two systems and the relaxation effect in LiFePO4 is attributed to a phase transformation mechanism, and the mesoscale morphology and charge conductivity of the electrodes. These discoveries demonstrate feasibility and power of in situ soft X-ray spectroscopy for studying integrated and dynamic effects in batteries. PMID:24100759

  4. Distinct charge dynamics in battery electrodes revealed by in situ and operando soft X-ray spectroscopy

    NASA Astrophysics Data System (ADS)

    Liu, Xiaosong; Wang, Dongdong; Liu, Gao; Srinivasan, Venkat; Liu, Zhi; Hussain, Zahid; Yang, Wanli

    2013-10-01

    Developing high-performance batteries relies on material breakthroughs. During the past few years, various in situ characterization tools have been developed and have become indispensible in studying and the eventual optimization of battery materials. However, soft X-ray spectroscopy, one of the most sensitive probes of electronic states, has been mainly limited to ex situ experiments for battery research. Here we achieve in situ and operando soft X-ray absorption spectroscopy of lithium-ion battery cathodes. Taking advantage of the elemental, chemical and surface sensitivities of soft X-rays, we discover distinct lithium-ion and electron dynamics in Li(Co1/3Ni1/3Mn1/3)O2 and LiFePO4 cathodes in polymer electrolytes. The contrast between the two systems and the relaxation effect in LiFePO4 is attributed to a phase transformation mechanism, and the mesoscale morphology and charge conductivity of the electrodes. These discoveries demonstrate feasibility and power of in situ soft X-ray spectroscopy for studying integrated and dynamic effects in batteries.

  5. Recent progress on synchrotron-based in-situ soft X-ray spectroscopy for energy materials.

    PubMed

    Liu, Xiaosong; Yang, Wanli; Liu, Zhi

    2014-12-10

    Soft X-ray spectroscopy (SXS) techniques such as photoelectron spectroscopy, soft X-ray absorption spectroscopy and X-ray emission spectroscopy are efficient and direct tools to probe electronic structures of materials. Traditionally, these surface sensitive soft X-ray techniques that detect electrons or photons require high vacuum to operate. Many recent in situ instrument developments of these techniques have overcome this vacuum barrier. One can now study many materials and model devices under near ambient, semi-realistic, and operando conditions. Further developments of integrating the realistic sample environments with efficient and high resolution detection methods, particularly at the high brightness synchrotron light sources, are making SXS an important tool for the energy research community. In this progress report, we briefly describe the basic concept of several SXS techniques and discuss recent development of SXS instruments. We then present several recent studies, mostly in situ SXS experiments, on energy materials and devices. Using these studies, we would like to highlight that the integration of SXS and in situ environments can provide in-depth insight of material's functionality and help researchers in new energy material developments. The remaining challenges and critical research directions are discussed at the end. PMID:24799004

  6. In-situ observation of nickel oxidation using synchrotron based full-field transmission X-ray microscopy

    NASA Astrophysics Data System (ADS)

    Kiss, Andrew M.; Harris, William M.; Wang, Steve; Vila-Comamala, Joan; Deriy, Alex; Chiu, Wilson K. S.

    2013-02-01

    An in situ imaging-based approach is reported to study chemical reactions using full-field transmission x-ray microscopy (TXM). Ni particles were oxidized at temperatures between 400 and 850 °C in the TXM to directly observe their morphology change while the chemical composition is monitored by x-ray absorption near edge spectroscopy. Reaction rates and activation energies are calculated from the image data. The goal of this effort is to better understand Ni oxidation in electrode materials. The approach developed will be an effective technique for directly studying chemical reactions of particles and their behavior at the nano-scale.

  7. Design and operation of an in situ high pressure reaction cell for x-ray absorption spectroscopy.

    SciTech Connect

    Bare, S. R.; Yang, N.; Kelly, S. D.; Mickelson, G. E.; Modica, F. S.; UOP LLC; EXAFS Analysis

    2007-01-01

    The design and initial operation of an in situ catalysis reaction cell for x-ray absorption spectroscopy measurements at high pressure is described. The design is based on an x-ray transparent tube fabricated from beryllium. This forms a true plug flow reactor for catalysis studies. The reactor is coupled to a portable microprocessor-controlled versatile feed system, and incorporates on-line analysis of reaction products. XAFS data recorded during the reduction of a NiRe/carbon catalyst at 4 bar are used to illustrate the performance of the reactor.

  8. Investigation of Sn surface segregation during GeSn epitaxial growth by Auger electron spectroscopy and energy dispersive x-ray spectroscopy

    NASA Astrophysics Data System (ADS)

    Tsukamoto, Takahiro; Hirose, Nobumitsu; Kasamatsu, Akifumi; Mimura, Takashi; Matsui, Toshiaki; Suda, Yoshiyuki

    2015-02-01

    The mechanism of Sn surface segregation during the epitaxial growth of GeSn on Si (001) substrates was investigated by Auger electron spectroscopy and energy dispersive X-ray spectroscopy. Sn surface segregation depends on the growth temperature and Sn content of GeSn layers. During Sn surface segregation, Sn-rich nanoparticles form and move on the surface during the deposition, which results in a rough surface owing to facet formation. The Sn-rich nanoparticles moving on the surface during the deposition absorb Sn from the periphery and yield a lower Sn content, not on the surface but within the layer, because the Sn surface segregation and the GeSn deposition occur simultaneously. Sn surface segregation can occur at a lower temperature during the deposition compared with that during postannealing. This suggests that the Sn surface segregation during the deposition is strongly promoted by the migration of deposited Ge and Sn adatoms on the surface originating from the thermal effect of substrate temperature, which also suggests that limiting the migration of deposited Ge and Sn adatoms can reduce the Sn surface segregation and improve the crystallinity of GeSn layers.

  9. Chemical and morphological study of gunshot residue persisting on the shooter by means of scanning electron microscopy and energy dispersive X-ray spectrometry.

    PubMed

    Brożek-Mucha, Zuzanna

    2011-12-01

    Persistence of gunshot residue (GSR) simultaneously collected from hands, face and hair, and clothing of the shooting person was examined. Samples were collected from five shooters in nine time intervals after a single shoot with a Luger 9 mm pistol, in the range of 0-4 h and examined with scanning electron microscopy and energy dispersive X-ray spectrometry. Numbers of particles, frequencies of occurrence of certain compositions of particles, and their sizes in function of the time intervals were inspected. The greatest numbers of particles were observed in samples collected from hands right after shooting, but they decrease quickly with time. In samples collected from the face smaller initial numbers of particles were found, but they lasted at a similar level longer. The estimated half-life times of particles were less than 1 h for samples taken from the hands, over 1 h for clothing and about 2-3 h for the face. In samples collected at longer intervals after shooting, there were particles present of small sizes and irregular shapes. The results demonstrate that including evidence collected from the suspect's face and hair may increase the probability of detection of GSR in cases when the suspect has not been apprehended immediately after the investigated incident. PMID:22051052

  10. Analysis of trace elements during different developmental stages of somatic embryogenesis in Plantago ovata Forssk using energy dispersive X-ray fluorescence.

    PubMed

    Saha, Priyanka; Raychaudhuri, Sarmistha Sen; Sudarshan, Mathummal; Chakraborty, Anindita

    2010-06-01

    Energy dispersive X-ray fluorescence (ED-XRF) technique has been used for the determination of trace element profile during different developmental stages of somatic embryogenic callus of an economically important medicinal plant, Plantago ovata Forssk. Somatic embryogenesis is a plant tissue culture-based technique, which is used for plant regeneration and crop improvement. In the present investigation, elemental content was analysed using ED-XRF technique during different developmental stages and also determine the effect of additives--casein hydrolysate and coconut water on the trace elemental profile of embryogenic callus tissue of P. ovata. Subsequent experiments showed significant alteration in the concentration of K, Ca, Mn, Fe, Zn, Cu, Br, and Sr in both the embryogenic and non-embryogenic callus. Higher K, Ca, Fe, Cu, and Zn accumulation was in embryogenic tissue stage compared to other stages, suggesting these elements are crucial for successful embryogenesis. The results suggest that this information could be useful for formulating a media for in vitro embryo induction of P. ovata. PMID:19696971

  11. Role of trace elements (Zn, Sr, Fe) in bone development: energy dispersive X-ray fluorescence study of rat bone and tooth tissue.

    PubMed

    Maciejewska, Karina; Drzazga, Zofia; Kaszuba, Michał

    2014-01-01

    Osteoporosis is one of the most common debilitating disease around the world and it is more and more established among young people. There are well known recommendations for nutrition of newborns and children concerning adequate calcium and vitamin D intake in order to maintain proper bone density. Nevertheless, important role in structure and function of a healthy bone tissue is played by an integration between all constituents including elements other than Ca, like trace elements, which control vital processes in bone tissue. It is important from scientific point of view as well as prevention of bone diseases, to monitor the mineralization process considering changes of the concentration of minerals during first stage of bone formation. This work presents studies of trace element (zinc, strontium, and iron) concentration in bones and teeth of Wistar rats at the age of 7, 14, and 28 days. Energy dispersive X-ray fluorescence (EDXRF) was used to examine mandibles, skulls, femurs, tibiae, and incisors. The quantitative analysis was performed using fundamental parameters method (FP). Zn and Sr concentrations were highest for the youngest individuals and decreased with age of rats, while Fe content was stable in bone matrix for most studied bones. Our results reveal the necessity of monitoring concentration of not only major, but also minor elements, because the trace elements play special role in the first period of bone development. PMID:24615876

  12. Post-mortem interval estimation of human skeletal remains by micro-computed tomography, mid-infrared microscopic imaging and energy dispersive X-ray mapping

    PubMed Central

    Hatzer-Grubwieser, P.; Bauer, C.; Parson, W.; Unterberger, S. H.; Kuhn, V.; Pemberger, N.; Pallua, Anton K.; Recheis, W.; Lackner, R.; Stalder, R.; Pallua, J. D.

    2015-01-01

    In this study different state-of-the-art visualization methods such as micro-computed tomography (micro-CT), mid-infrared (MIR) microscopic imaging and energy dispersive X-ray (EDS) mapping were evaluated to study human skeletal remains for the determination of the post-mortem interval (PMI). PMI specific features were identified and visualized by overlaying molecular imaging data and morphological tissue structures generated by radiological techniques and microscopic images gained from confocal microscopy (Infinite Focus (IFM)). In this way, a more distinct picture concerning processes during the PMI as well as a more realistic approximation of the PMI were achieved. It could be demonstrated that the gained result in combination with multivariate data analysis can be used to predict the Ca/C ratio and bone volume (BV) over total volume (TV) for PMI estimation. Statistical limitation of this study is the small sample size, and future work will be based on more specimens to develop a screening tool for PMI based on the outcome of this multidimensional approach. PMID:25878731

  13. [The evaluation of uncertainty in the results for elements rubidium, strontium, yttrium and zirconium in silicate geological samples by polarized energy dispersive X-ray fluorescence spectrometry].

    PubMed

    Wang, Yi-Ya; Zhan, Xiu-Chun; Yuan, Ji-Hai; Fan, Xing-Tao

    2011-06-01

    A method for evaluation of uncertainty was established with standard deviation of relative error. Utilizing a polarized energy dispersive X ray fluorescence spectrometer (P-EDXRF)X-lab 2000 with pressed polyethylene-backed pellets, 76 national reference materials and 89 geological examination samples were analyzed, the results indicated that the relative errors consist with the normal distribution with confidence level 95%. The section standard deviations of relative errors acted as method global relative uncertainty and expanded factor was 2. The section relative uncertainty caused by precision was analyzed and relative uncertainty caused by accuracy based on the error transfer formula was isolated. The ratio of relative uncertainty caused by accuracy to the global relative uncertainty was different with different levels and elements. Two methods validated that the evaluation of global uncertainty is reasonable, with the first method being the formula of audited results in laboratory, and the second being the comparison of standard value with expanded uncertainty and a revised value with expanded uncertainty. PMID:21847963

  14. Application of Scanning Electron Microscopy/Energy-Dispersive X-Ray Spectroscopy for Characterization of Detrital Minerals in Karst Cave Speleothems.

    PubMed

    Zupančič, Nina; Miler, Miloš; Šebela, Stanka; Jarc, Simona

    2016-02-01

    Micro-scale observations in karst caves help to identify different processes that shaped local morphology. Scanning electron microscopy/energy-dispersive X-ray spectroscopy inspection of speleothems from two karst caves in Slovenia, Predjama and Črna Jama, confirmed the presence of sub-angular to sub-rounded detrital fragments of clay minerals, feldspars, quartz, Fe-oxides/hydroxides, rutile and Nb-rutile, xenotime, kassite, allanite, fluorapatite, epidote, ilmenite, monazite, sphene, and zircon, between 2 and 50 μm across. These occur in porous layers separating calcite laminae in the clayey coating on the layer below the surface of the speleothems, and are also incorporated within actual crystals. It is likely that they are derived from the weathered rocks of the Eocene flysch. Probably they were first transported into the caves by floodwaters forming cave sediments. Later, depending upon the climate conditions, they were moved by air currents or by water to the surface of active speleothems. They might also be redeposited from overlying soils enriched with wind-transported minerals from the flysch, or from higher passages filled with weathered flysch sediment, by drip water percolating through the fissured limestone. As some of the identified minerals are carriers of rare earth elements, Ti and Zr, their presence could affect any palaeoclimatic interpretations that are based upon the geochemical composition of the speleothems. PMID:26914996

  15. A case of hut lung: scanning electron microscopy with energy dispersive x-ray spectroscopy analysis of a domestically acquired form of pneumoconiosis.

    PubMed

    Mukhopadhyay, Sanjay; Gujral, Manmeet; Abraham, Jerrold L; Scalzetti, Ernest M; Iannuzzi, Michael C

    2013-07-01

    Hut lung is a pneumoconiosis caused by exposure to smoke derived from biomass fuels used for cooking in poorly ventilated huts. We report, to our knowledge, the first analysis of the dust deposited in the lungs in hut lung by scanning electron microscopy with energy dispersive x-ray spectroscopy (SEM/EDS). A Bhutanese woman presented with shortness of breath and an abnormal chest radiograph. Chest CT scan showed innumerable tiny bilateral upper lobe centrilobular nodules. Transbronchial biopsy revealed mild interstitial fibrosis with heavy interstitial deposition of black dust. SEM/EDS showed that the dust was carbonaceous, with smaller yet substantial numbers of silica and silicate particles. Additional history revealed use of a wood/coal-fueled stove in a small, poorly ventilated hut for 45 years. The possibility of hut lung should be considered in women from countries where use of biomass-fueled stoves for cooking is common. Our findings support the classification of this condition as a mixed-dust pneumoconiosis. PMID:23880681

  16. Energy-dispersive x-Ray Analysis of Phosphorus, Potassium, Magnesium, and Calcium in Globoid Crystals in Protein Bodies from Different Regions of Cucurbita maxima Embryos 1

    PubMed Central

    Lott, John N. A.; Greenwood, John S.; Vollmer, Catherine M.; Buttrose, Mark S.

    1978-01-01

    The seeds of Cucurbita maxima contain protein bodies with electrondense globoid crystals. Because of their density globoid crystals are ideal material for energy-dispersive x-ray (EDX) analysis studies of elemental composition. Fixation trials were carried out to test globoid crystal extraction during glutaraldehyde fixation, water washing, and ethanol dehydration. Glutaraldehyde fixation without subsequent washing or dehydration alone produced no significant changes in elemental composition of cotyledon globoid crystals. If glutaraldehyde fixation was followed by water washes or ethanol dehydration there was some loss of the major globoid crystal elements but the relative percentages of the elements P, K, Ca, and Mg remained relatively unchanged. In this paper results of a study of the P, K, Mg, and Ca content of globoid crystals in different tissues of squash embryos are presented. The globoid crystals in the radicle were found to be the least dense in the embryo. Globoid crystals from all embryo regions contained P, K, and Mg. In the various embryo regions P and Mg maintained relatively constant proportions of the globoid crystal composition while K and Ca varied. Of particular significance is the distribution of Ca which is generally an immobile element. Calcium was found in highest amounts in the globoid crystals of the radicle and stem regions while globoid crystals in much of the cotyledon contained little, if any, Ca. The Ca storage thus seems to be spatially arranged in a manner that would aid early growth of the root-shoot axis. PMID:16660439

  17. Scanning electron microscopy coupled with energy-dispersive X-ray spectrometry for quick detection of sulfur-oxidizing bacteria in environmental water samples

    NASA Astrophysics Data System (ADS)

    Sun, Chengjun; Jiang, Fenghua; Gao, Wei; Li, Xiaoyun; Yu, Yanzhen; Yin, Xiaofei; Wang, Yong; Ding, Haibing

    2016-03-01

    Detection of sulfur-oxidizing bacteria has largely been dependent on targeted gene sequencing technology or traditional cell cultivation, which usually takes from days to months to carry out. This clearly does not meet the requirements of analysis for time-sensitive samples and/or complicated environmental samples. Since energy-dispersive X-ray spectrometry (EDS) can be used to simultaneously detect multiple elements in a sample, including sulfur, with minimal sample treatment, this technology was applied to detect sulfur-oxidizing bacteria using their high sulfur content within the cell. This article describes the application of scanning electron microscopy imaging coupled with EDS mapping for quick detection of sulfur oxidizers in contaminated environmental water samples, with minimal sample handling. Scanning electron microscopy imaging revealed the existence of dense granules within the bacterial cells, while EDS identified large amounts of sulfur within them. EDS mapping localized the sulfur to these granules. Subsequent 16S rRNA gene sequencing showed that the bacteria detected in our samples belonged to the genus Chromatium, which are sulfur oxidizers. Thus, EDS mapping made it possible to identify sulfur oxidizers in environmental samples based on localized sulfur within their cells, within a short time (within 24 h of sampling). This technique has wide ranging applications for detection of sulfur bacteria in environmental water samples.

  18. Scanning Electron Microscopy and Energy Dispersive X-ray Spectroscopy Studies on Processed Tooth Graft Material by Vacuum-ultrasonic Acceleration

    PubMed Central

    Lee, Eun-Young; Kim, Eun-Suk; Kim, Kyung-Won

    2014-01-01

    Purpose: The current gold standard for clinical jawbone formation involves autogenous bone as a graft material. In addition, demineralized dentin can be an effective graft material. Although demineralized dentin readily induces heterotopic bone formation, conventional decalcification takes three to five days, so, immediate bone grafting after extraction is impossible. This study evaluated the effect of vacuum ultrasonic power on the demineralization and processing of autogenous tooth material and documented the clinical results of rapidly processed autogenous demineralized dentin (ADD) in an alveolar defects patient. Methods: The method involves the demineralization of extracted teeth with detached soft tissues and pulp in 0.6 N HCl for 90 minutes using a heat controlled vacuum-ultrasonic accelerator. The characteristics of processed teeth were evaluated by scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). Bone grafting using ADD was performed for narrow ridges augmentation in the mandibular area. Results: The new processing method was completed within two hours regardless of form (powder or block). EDS and SEM uniformly demineralized autotooth biomaterial. After six months, bone remodeling was observed in augmented sites and histological examination showed that ADD particles were well united with new bone. No unusual complications were encountered. Conclusion: This study demonstrates the possibility of preparing autogenous tooth graft materials within two hours, allowing immediate one-day grafting after extraction. PMID:27489819

  19. Morphological and chemical changes in dentin after using endodontic agents: Fourier transform Raman spectroscopy, energy-dispersive x-ray fluorescence spectrometry, and scanning electron microscopy study

    NASA Astrophysics Data System (ADS)

    Pascon, Fernanda Miori; Kantovitz, Kamila Rosamilia; Soares, Luís Eduardo Silva; Santo, Ana Maria do Espírito; Martin, Airton Abraha~o.; Puppin-Rontani, Regina Maria

    2012-07-01

    We examine the morphological and chemical changes in the pulp chamber dentin after using endodontic agents by scanning electron microscopy (SEM), Fourier transform Raman spectroscopy (FT-Raman), and micro energy-dispersive x-ray fluorescence spectrometry (μEDXRF). Thirty teeth were sectioned exposing the pulp chamber and divided by six groups (n=5): NT-no treatment; CHX-2% chlorhexidine; CHXE-2% chlorhexidine+17% EDTA E-17% EDTA; SH5-5.25% NaOCl; SH5E-5.25% NaOCl+17% EDTA. The inorganic and organic content was analyzed by FT-Raman. μEDXRF examined calcium (Ca) and phosphorus (P) content as well as Ca/P ratio. Impressions of specimens were evaluated by SEM. Data were submitted to Kruskal-Wallis and Dunn tests (p<0.05). Differences were observed among groups for the 960 cm-1 peak. Ca and P content differences were significant (SH5>NT=SH5E>CHX>E>CHXE). CHXE and E presented the highest Ca/P ratio values compared to the other groups (p<0.05). The SEM images in the EDTA-treated groups had the highest number of open tubules. Erosion in the tubules was observed in CHX and SH5E groups. Endodontic agents change the inorganic and organic content of pulp chamber dentin. NaOCl used alone, or in association with EDTA, was the most effective agent considering chemical and morphological approaches.

  20. Effects of Er:YAG laser irradiation and manipulation treatments on dentin components, part 2: energy-dispersive X-ray fluorescence spectrometry study

    NASA Astrophysics Data System (ADS)

    Silva Soares, Luís Eduardo; Do Espírito Santo, Ana Maria; Brugnera, Aldo; Zanin, Fátima Antônia Aparecida; Martin, Airton Abraha~O.

    2009-03-01

    The effects of laser etching, decontamination, and storage treatments on dentin components were studied by energy-dispersive X-ray fluorescence spectrometry (EDXRF). Thirty bovine incisors were prepared to expose the dentin surface and then divided into two main groups based upon the decontamination process and storage procedure: autoclaved (group A, n=15) or stored in aqueous thymol solution (group B, n=15). The surfaces of the dentin slices were schematically divided into four areas, with each one corresponding to a treatment subgroup. The specimens were either etched with phosphoric acid (control subgroup) or irradiated with erbium-doped yttrium-aluminum-garnet (Er:YAG) laser (subgroups: I-80 mJ, II-120 mJ, and III-180 mJ). Samples were analyzed by micro-EDXRF, yielding three spectra for each area (before and after treatment). Surface mappings covering an area of 80×60 points with steps of 20 μm were also performed on selected specimens. The amount of Ca and P in group A specimens decreased significantly (P<0.05) after the acid etching and the Ca/P ratio increased (P<0.001). Er:YAG laser-etching using lower laser energies did not produce significant changes in dentin components. The mapping data support the hypothesis that acid etching on dentin produced a more chemically homogeneous surface and thus a more favorable surface for the diffusion of adhesive monomers.

  1. Energy-dispersive x-Ray Analysis of Phosphorus, Potassium, Magnesium, and Calcium in Globoid Crystals in Protein Bodies from Different Regions of Cucurbita maxima Embryos.

    PubMed

    Lott, J N; Greenwood, J S; Vollmer, C M

    1978-06-01

    The seeds of Cucurbita maxima contain protein bodies with electrondense globoid crystals. Because of their density globoid crystals are ideal material for energy-dispersive x-ray (EDX) analysis studies of elemental composition. Fixation trials were carried out to test globoid crystal extraction during glutaraldehyde fixation, water washing, and ethanol dehydration. Glutaraldehyde fixation without subsequent washing or dehydration alone produced no significant changes in elemental composition of cotyledon globoid crystals. If glutaraldehyde fixation was followed by water washes or ethanol dehydration there was some loss of the major globoid crystal elements but the relative percentages of the elements P, K, Ca, and Mg remained relatively unchanged. In this paper results of a study of the P, K, Mg, and Ca content of globoid crystals in different tissues of squash embryos are presented. The globoid crystals in the radicle were found to be the least dense in the embryo. Globoid crystals from all embryo regions contained P, K, and Mg. In the various embryo regions P and Mg maintained relatively constant proportions of the globoid crystal composition while K and Ca varied. Of particular significance is the distribution of Ca which is generally an immobile element. Calcium was found in highest amounts in the globoid crystals of the radicle and stem regions while globoid crystals in much of the cotyledon contained little, if any, Ca. The Ca storage thus seems to be spatially arranged in a manner that would aid early growth of the root-shoot axis. PMID:16660439

  2. Elemental concentration analysis in soil contaminated with recyclable urban garbage by tube-excited energy-dispersive X-ray fluorescence

    NASA Astrophysics Data System (ADS)

    Anjos, M. J.; Lopes, R. T.; Jesus, E. F. O.; Assis, J. T.; Cesareo, R.; Barroso, R. C.; Barradas, C. A. A.

    2002-11-01

    Soil and radish (Raphanus Sp) samples from areas treated with organic compost of recyclable urban garbage were quantitatively analyzed by using tube-excited energy-dispersive X-ray fluorescence analysis. Soils treated with 10, 20 and 30 t/ha of recyclable urban garbage and control soil were analyzed. The layer soils were collected at 0-5, 5-10, 10-20, 20-40, 40-60 cm depth. It was possible simultaneously to determine the elemental concentration of various elements: K, Ca, Ti, Mn, Fe, Cu, Zn, Br, Rb, Sr, Zr and Pb in recyclable urban garbage, soil treated with organic compost of recyclable urban garbage and radish plants cultivated in these soils. The elemental concentration of K, Ca, Ti and Fe were determined at percent level (macro-elements) and the other elements at ppm level (micro-elements). It was also possible to observe a significant increase in the contents of K, Ca, Zn, Rb, Sr, Zr and Pb in the soil treated in comparison with the control soil and it was also verified whether the transport of these elements to radish plants cultivated in these soils occurred.

  3. [Chemical composition analysis of early neolithic pottery unearthed from Xiaohuangshang site, Zhejiang Province and Jiahu site, Henan Province by energy disperse X-ray fluorescence].

    PubMed

    Chen, Qian-Qian; Yang, Yu-Zhang; Zhang, Ju-Zhong; Cui, Wei

    2011-11-01

    The major elements in the early neolithic potteries unearthed from Xiaohuangshan site, Zhejiang Province and Jiahu site, Henan Province were determined by energy disperse X-ray fluorescence (EDXRF). The results show that the chemical compositions of the potteries from these two sites possess obvious regional features respectively. Compared with the specimen from Jiahu site, the potteries from Xiaohuangshan site have the common feature of ancient Chinese southern ceramics with high silicon and low aluminum contents. Simultaneously, the chemical composition of Xiaohuangshan pottery samples nearly unchanged from its early stage to the last stage. This phenomenon indicates that the source of the ceramic raw materials of Xiaohuangshan site was stable, and the continuous improvement of its pottery quality was mainly due to the progress in sintering techniques. However, the chemical composition of Jiahu potteries changed a lot in its three different periods. This change occurred because a large number of admixtures were added to the pottery bodies to improve their operating performances. These results also show that the improvements of pottery making techniques in different Chinese areas may have their own evolution directions respectively for the different geographical environments. PMID:22242535

  4. An in situ atomic force microscope for normal-incidence nanofocus X-ray experiments.

    PubMed

    Vitorino, M V; Fuchs, Y; Dane, T; Rodrigues, M S; Rosenthal, M; Panzarella, A; Bernard, P; Hignette, O; Dupuy, L; Burghammer, M; Costa, L

    2016-09-01

    A compact high-speed X-ray atomic force microscope has been developed for in situ use in normal-incidence X-ray experiments on synchrotron beamlines, allowing for simultaneous characterization of samples in direct space with nanometric lateral resolution while employing nanofocused X-ray beams. In the present work the instrument is used to observe radiation damage effects produced by an intense X-ray nanobeam on a semiconducting organic thin film. The formation of micrometric holes induced by the beam occurring on a timescale of seconds is characterized. PMID:27577764

  5. A rotational and axial motion system load frame insert for in situ high energy x-ray studies.

    PubMed

    Shade, Paul A; Blank, Basil; Schuren, Jay C; Turner, Todd J; Kenesei, Peter; Goetze, Kurt; Suter, Robert M; Bernier, Joel V; Li, Shiu Fai; Lind, Jonathan; Lienert, Ulrich; Almer, Jonathan

    2015-09-01

    High energy x-ray characterization methods hold great potential for gaining insight into the behavior of materials and providing comparison datasets for the validation and development of mesoscale modeling tools. A suite of techniques have been developed by the x-ray community for characterizing the 3D structure and micromechanical state of polycrystalline materials; however, combining these techniques with in situ mechanical testing under well characterized and controlled boundary conditions has been challenging due to experimental design requirements, which demand new high-precision hardware as well as access to high-energy x-ray beamlines. We describe the design and performance of a load frame insert with a rotational and axial motion system that has been developed to meet these requirements. An example dataset from a deforming titanium alloy demonstrates the new capability. PMID:26429452

  6. A rotational and axial motion system load frame insert for in situ high energy x-ray studies

    SciTech Connect

    Shade, Paul A. Schuren, Jay C.; Turner, Todd J.; Blank, Basil; Kenesei, Peter; Goetze, Kurt; Lienert, Ulrich; Almer, Jonathan; Suter, Robert M.; Bernier, Joel V.; Li, Shiu Fai; Lind, Jonathan

    2015-09-15

    High energy x-ray characterization methods hold great potential for gaining insight into the behavior of materials and providing comparison datasets for the validation and development of mesoscale modeling tools. A suite of techniques have been developed by the x-ray community for characterizing the 3D structure and micromechanical state of polycrystalline materials; however, combining these techniques with in situ mechanical testing under well characterized and controlled boundary conditions has been challenging due to experimental design requirements, which demand new high-precision hardware as well as access to high-energy x-ray beamlines. We describe the design and performance of a load frame insert with a rotational and axial motion system that has been developed to meet these requirements. An example dataset from a deforming titanium alloy demonstrates the new capability.

  7. Geological Carbon Sequestration: new insights from in-situ Synchrotron X-ray Microtomography

    NASA Astrophysics Data System (ADS)

    Voltolini, M.; Kwon, T.; Ajo Franklin, J. B.

    2012-12-01

    In a world with rapidly increasing atmospheric CO2 concentrations, a variety of scalable technologies are being considered to mitigate emissions from the combustion of fossil fuels; among these approaches, geological carbon storage (GCS) is being actively tested at a variety of subsurface sites. Despite these activities, a mechanistic understanding of multiphase flow in scCO2/brine systems at the pore scale is still being developed. The distribution of scCO2 in the pore space controls a variety of processes at the continuum scale including CO2 dissolution rate (by way of brine/CO2 contact area), capillary trapping, and residual brine fraction. Virtually no dynamic measurements of the pore-scale distribution of scCO2 in real geological samples have been made in three dimensions leaving models describing multi-phase fluid dynamics, reactive transport, and geophysical properties reliant on analog systems (often using fewer spatial dimensions, different fluids, or lower pressures) or theoretical models describing phase configurations. We present dynamic pore-scale imagery of scCO2 invasion dynamics in a 3D geological sample, in this case a quartz-rich sandstone core extracted from the Domengine Fm, a regionally extensive unit which is currently a target for future GCS operations in the Sacramento Basin. This dataset, acquired using synchrotron X-ray micro tomography (SXR-μCT) and high speed radiography, was made possible by development of a controlled P/T flow-through triaxial cell compatible with X-ray imaging in the 8-40 keV range. These experiments successfully resolved scCO2 and brine phases at a spatial resolution of 4.47 μm while the sample was kept at in situ conditions (45°C, 9 MPa pore pressure, 14 MPa hydrostatic confining stress) during drainage and imbibition cycles. Image volumes of the dry, brine saturated, and partially scCO2 saturated sample were captured and were used to correlate aspects of rock microstructure to development of the invasion front

  8. Evolution of magma textures during deformation: Insights from in situ X-ray tomography experiments

    NASA Astrophysics Data System (ADS)

    Degruyter, W.; Cordonnier, B.; Manga, M.; Haboub, A.; Andrews, B. J.; Dennen, R. L.; MacDowell, A.; Parkinson, D. Y.

    2012-12-01

    Pyroclasts provide snapshots of the state of the magma at fragmentation or emplacement. Their textures record the deformation and degassing magma underwent prior to quenching. Understanding the link between the final texture and the processes that created them requires experimental reproduction of volcanic conditions under constrained parameters. Technological advances at the X-ray tomography beamline at the Advanced Light Source, Lawrence Berkeley National Laboratory have now made it possible to visualize magma in 3D as it is being deformed at high temperature, which allows us to visualize and quantify the processes that form pyroclasts. We use a fast readout camera that allows tomography on a few minutes timescale in combination with a high temperature uni-axial apparatus transparent to tomography. We heated obsidian samples from Big Glass Mountain, California and andesitic glass from Pahoa, California at various temperatures up to 1400 K. After an initial foaming stage, the samples were subjected to pure shear flow at strain-rates varying between 10-6 s-1 and 10-2 s-1. Magma rheology measurements in the past have typically been restricted to bulk measurements and visualization before and after the experiment. This limits the ability to interpret the measured relationship between stress and strain-rate and the evolution of texture. The in situ scanning allows us to track the deformation or relaxation of individual bubbles, development of strain localization, crack initiation and makes it possible to directly correlate these processes to the bulk measurements of stress and strain. These new measurements will improve the interpretation of the textures found within the products produced by volcanic eruptions.

  9. In Situ Ambient Pressure X-ray Photoelectron Spectroscopy Studies of Lithium-Oxygen Redox Reactions

    SciTech Connect

    Lu, Yi-Chun; Crumlin, Ethan J.; Veith, Gabriel M.; Harding, Jonathon R.; Mutoro, Eva; Baggetto, Loïc; Dudney, Nancy J.; Liu, Zhi; Shao-Horn, Yang

    2012-10-08

    The lack of fundamental understanding of the oxygen reduction and oxygen evolution in nonaqueous electrolytes significantly hinders the development of rechargeable lithium-air batteries. Here we employ a solid-state Li4+xTi5O12/LiPON/LixV2O5 cell and examine in situ the chemistry of Li-O2 reaction products on LixV2O5 as a function of applied voltage under ultra high vacuum (UHV) and near ambient-pressure of oxygen using X-ray photoelectron spectroscopy (APXPS). Oxygen reduction and evolution reactions take place on the surface of the mixed electronic and Li+ ionic conductor, LixV2O5, which eliminate parasitic reactions between oxygen reduction/evolution reaction intermediates and aprotic electrolytes used in Li-O2 batteries reported to date. Under UHV, reversible lithium intercalation and de-intercalation from LixV2O5 was noted, where the changes in the vanadium valence state revealed from XPS in this study were comparable to that reported previously from Li/LixV2O5 thin film batteries. In presence of oxygen near ambient pressure, the LixV2O5 surface was covered gradually by the reaction product of oxygen reduction, namely lithium peroxide (Li2O2) (approximately 1-2 unit cells) upon discharge. Interestingly, the LixV2O5 surface became re-exposed upon charging, and the oxidation of Li2O2 began at much lower overpotentials (~240 mV) than the charge overpotentials of Li-O2 cells (~1000 mV) with aprotic electrolytes, which can be attributed to subnanometer-thick Li2O2 with surfaces free of contaminants such as carbonate species. Our study provides first evidence of reversible lithium peroxide formation and decomposition in situ on an oxide surface using a solid-state cell, and new insights into the reaction mechanism of Li-O2 chemistry.

  10. Design and Operation of a High Pressure Reaction Cell for in situ X-ray Absorption Spectroscopy

    SciTech Connect

    Bare,S.; Yang, N.; Kelly, S.; Mickelson, G.; Modica, F.

    2007-01-01

    X-ray absorption spectroscopy measurements of catalytic reactions have been instrumental in advancing the understanding of catalytic processes. These measurements require an in situ catalysis reaction cell with unique properties. Here we describe the design and initial operation of an in situ/operando catalysis reaction cell for transmission X-ray absorption spectroscopy measurements. The cell is designed: to be an ideal catalytic reactor with no mass transfer effects; to give the same conversion and selectivity under similar space velocities as standard laboratory micro-reactors; to be operational temperatures up to 600 {sup o}C and pressures up to 14 bar; to be X-ray transparent allowing XAS measurement to be collected in transmission for all elements with Z {>=} 23 (vanadium K-edge at 5.5 keV); to measure the actual catalyst bed temperature; to not use o-ring seals, or water cooling; to be robust, compact, easy to assemble, and use, and relatively low cost to produce. The heart of the cell is fabricated from an X-ray transparent beryllium tube that forms a plug flow reactor. XAFS data recorded during the reduction of a Re/{gamma}-A{sub 2}O{sub 3} catalyst as a function of hydrogen pressure from 0.05 to 8 bar, and from a Pt-Sn/{gamma}-A{sub 2}O{sub 3} catalyst during n-heptane reforming are given as initial examples of the versatility of the reactor.

  11. Combined in Situ X-ray absorption and diffuse reflectance infraredspectroscopy: An attractive tool for catalytic investigations

    SciTech Connect

    Marinkovic, N.S.; Ehrlich, S.; Wang, Q.; Barrio, L.; Khalid, S.; et.al.

    2010-11-24

    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 (EXAFS) and X-ray absorption near-edge structure (XANES) require synchrotron light. In order to ensure the same conditions during in situ catalysis for each method, a combined XAS/DRIFTS has been developed at beamline X18A at the National Synchrotron Light Source, Brookhaven National Laboratory. A rapid-scan FTIR spectrometer capable of both mid- and far-infrared measurements is equipped with an arm to redirect the IR beam outside the spectrometer. An in situ reaction chamber, equipped with glassy carbon windows for X-ray light and a KBr window for IR light passage is installed firmly on the arm. The reaction cell can be heated to 600 C and allows passage of gases through the catalyst so that both XAS and DRIFTS techniques can be done simultaneously in controlled environment conditions. Together with a fast-moving monochromator for quick-EXAFS and mass-spectrometric residual gas analysis, this new tool is a powerful method for testing catalytic reactions in real time.

  12. In-situ synchrotron x-ray spectroscopy of ruthenium nanoparticles modified with selenium for oxygen reduction reaction.

    SciTech Connect

    Inukai, J.; Cao, D.; Wieckowski, A.; Chang, K.-C.; Menzel, A.; Komanicky, V.; You, H.; Materials Science Division; Univ. of Illinois; Univ. of Yamanashi

    2007-11-15

    We used in situ Se K-edge X-ray spectroscopy to characterize Ru nanoparticles chemically modified with submonolayers of selenium (Se/Ru) [Cao et al. J. Electrochem. Soc. 2006, 153, A869]. X-ray powder diffraction verified that the Se/Ru catalyst had metallic Ru cores. The in situ X-ray absorption near edge structure taken at the open circuit potential showed that there were both elemental and oxidized selenium on the as-prepared Se/Ru samples. All selenium oxide was reduced to the elemental form of selenium by applying negative potentials. By applying positive potentials, selenium was subsequently reoxidized. The analysis of the extended X-ray absorption fine structure shows the appearance of selenium hydration (Se-OH{sub 2}) in a deaerated solution, which was not observed during the oxygen reduction reaction. We present evidence that Se-free Ru atoms play an important role in the ORR activity of the Se/Ru catalyst studied in this paper.

  13. In situ synchrotron x-ray spectroscopy of ruthenium nanoparticles modified with selenium for an oxygen reduction reaction.

    SciTech Connect

    Inukai, J.; Cao, D.; Wieckowski, A.; Chang, K.-C.; Menzel, A.; Komanicky, V.; You, H.; Univ. Illinois; Univ. Yamanashi

    2007-11-15

    We used in situ Se K-edge X-ray spectroscopy to characterize Ru nanoparticles chemically modified with submonolayers of selenium (Se/Ru) [Cao et al. J. Electrochem. Soc. 2006, 153, A869]. X-ray powder diffraction verified that the Se/Ru catalyst had metallic Ru cores. The in situ X-ray absorption near edge structure taken at the open circuit potential showed that there were both elemental and oxidized selenium on the as-prepared Se/Ru samples. All selenium oxide was reduced to the elemental form of selenium by applying negative potentials. By applying positive potentials, selenium was subsequently reoxidized. The analysis of the extended X-ray absorption fine structure shows the appearance of selenium hydration (Se-OH{sub 2}) in a deaerated solution, which was not observed during the oxygen reduction reaction. We present evidence that Se-free Ru atoms play an important role in the ORR activity of the Se/Ru catalyst studied in this paper.

  14. A modular reactor design for in situ synchrotron x-ray investigation of atomic layer deposition processes

    NASA Astrophysics Data System (ADS)

    Klug, Jeffrey A.; Weimer, Matthew S.; Emery, Jonathan D.; Yanguas-Gil, Angel; Seifert, Sönke; Schlepütz, Christian M.; Martinson, Alex B. F.; Elam, Jeffrey W.; Hock, Adam S.; Proslier, Thomas

    2015-11-01

    Synchrotron characterization techniques provide some of the most powerful tools for the study of film structure and chemistry. The brilliance and tunability of the Advanced Photon Source allow access to scattering and spectroscopic techniques unavailable with in-house laboratory setups and provide the opportunity to probe various atomic layer deposition (ALD) processes in situ starting at the very first deposition cycle. Here, we present the design and implementation of a portable ALD instrument which possesses a modular reactor scheme that enables simple experimental switchover between various beamlines and characterization techniques. As first examples, we present in situ results for (1) X-ray surface scattering and reflectivity measurements of epitaxial ZnO ALD on sapphire, (2) grazing-incidence small angle scattering of MnO nucleation on silicon, and (3) grazing-incidence X-ray absorption spectroscopy of nucleation-regime Er2O3 ALD on amorphous ALD alumina and single crystalline sapphire.

  15. Quantifying the Nucleation and Growth Kinetics of Microwave Nanochemistry Enabled by in Situ High-Energy X-ray Scattering.

    PubMed

    Liu, Qi; Gao, Min-Rui; Liu, Yuzi; Okasinski, John S; Ren, Yang; Sun, Yugang

    2016-01-13

    The fast reaction kinetics presented in the microwave synthesis of colloidal silver nanoparticles was quantitatively studied, for the first time, by integrating a microwave reactor with in situ X-ray diffraction at a high-energy synchrotron beamline. Comprehensive data analysis reveals two different types of reaction kinetics corresponding to the nucleation and growth of the Ag nanoparticles. The formation of seeds (nucleation) follows typical first-order reaction kinetics with activation energy of 20.34 kJ/mol, while the growth of seeds (growth) follows typical self-catalytic reaction kinetics. Varying the synthesis conditions indicates that the microwave colloidal chemistry is independent of concentration of surfactant. These discoveries reveal that the microwave synthesis of Ag nanoparticles proceeds with reaction kinetics significantly different from the synthesis present in conventional oil bath heating. The in situ X-ray diffraction technique reported in this work is promising to enable further understanding of crystalline nanomaterials formed through microwave synthesis. PMID:26625184

  16. A new experimental cell for in situ and operandoX-ray absorption measurements in heterogeneous catalysis.

    PubMed

    Girardon, J S; Khodakov, A Y; Capron, M; Cristol, S; Dujardin, C; Dhainaut, F; Nikitenko, S; Meneau, F; Bras, W; Payen, E

    2005-09-01

    A new X-ray absorption cell dedicated to in situ and operando experiments in heterogeneous catalysis has been built and tested. The cell consists of several boron nitride and stainless steel plates linked together using graphite seals. It allows the measurement of XANES and EXAFS spectra of heterogeneous catalysts within a wide range of photon energies in transmission mode under the flow of various oxidative and reductive gas mixtures at elevated temperatures. The cell is compact and easy to build. Catalysts are loaded into the cell as powders. The use of boron nitride and a small beam pathlength in the cell result in a low absorption of the X-ray beam at lower energies. The cell was tested by in situ characterizing cobalt species during oxidative and reductive pre-treatments of a silica-supported Fischer-Tropsch catalyst. An operando study of methanol conversion over alumina-supported molybdenum catalysts was also carried out. PMID:16120995

  17. A modular reactor design for in situ synchrotron x-ray investigation of atomic layer deposition processes

    SciTech Connect

    Klug, Jeffrey A. Emery, Jonathan D.; Martinson, Alex B. F.; Proslier, Thomas; Weimer, Matthew S.; Yanguas-Gil, Angel; Elam, Jeffrey W.; Seifert, Sönke; Schlepütz, Christian M.; Hock, Adam S.

    2015-11-15

    Synchrotron characterization techniques provide some of the most powerful tools for the study of film structure and chemistry. The brilliance and tunability of the Advanced Photon Source allow access to scattering and spectroscopic techniques unavailable with in-house laboratory setups and provide the opportunity to probe various atomic layer deposition (ALD) processes in situ starting at the very first deposition cycle. Here, we present the design and implementation of a portable ALD instrument which possesses a modular reactor scheme that enables simple experimental switchover between various beamlines and characterization techniques. As first examples, we present in situ results for (1) X-ray surface scattering and reflectivity measurements of epitaxial ZnO ALD on sapphire, (2) grazing-incidence small angle scattering of MnO nucleation on silicon, and (3) grazing-incidence X-ray absorption spectroscopy of nucleation-regime Er{sub 2}O{sub 3} ALD on amorphous ALD alumina and single crystalline sapphire.

  18. A modular reactor design for in situ synchrotron X-ray investigation of atomic layer deposition processes

    SciTech Connect

    Klug, Jeffrey A.; Weimer, Matthew S.; Emery, Jonathan D.; Yanguas-Gil, Angel; Seifert, Sonke; Schleputz, Christian M.; Martinson, Alex B. F.; Elam, Jeffrey W.; Hock, Adam S.; Proslier, Thomas

    2015-11-01

    Synchrotron characterization techniques provide some of the most powerful tools for the study of film structure and chemistry. The brilliance and tunability of the Advanced Photon Source allow access to scattering and spectroscopic techniques unavailable with in-house laboratory setups and provide the opportunity to probe various atomic layer deposition (ALD) processes in situ starting at the very first deposition cycle. Here, we present the design and implementation of a portable ALD instrument which possesses a modular reactor scheme that enables simple experimental switchover between various beamlines and characterization techniques. As first examples, we present \\textit{in situ} results for 1.) X-ray surface scattering and reflectivity measurements of epitaxial ZnO ALD on sapphire, 2.) grazing-incidence small angle scattering of MnO nucleation on silicon, and 3.) grazing-incidence X-ray absorption spectroscopy of nucleation-regime Er2O3 ALD on amorphous ALD alumina and single crystalline sapphire.

  19. In situ X-ray diffraction monitoring of a mechanochemical reaction reveals a unique topology metal-organic framework

    NASA Astrophysics Data System (ADS)

    Katsenis, Athanassios D.; Puškarić, Andreas; Štrukil, Vjekoslav; Mottillo, Cristina; Julien, Patrick A.; Užarević, Krunoslav; Pham, Minh-Hao; Do, Trong-On; Kimber, Simon A. J.; Lazić, Predrag; Magdysyuk, Oxana; Dinnebier, Robert E.; Halasz, Ivan; Friščić, Tomislav

    2015-03-01

    Chemical and physical transformations by milling are attracting enormous interest for their ability to access new materials and clean reactivity, and are central to a number of core industries, from mineral processing to pharmaceutical manufacturing. While continuous mechanical stress during milling is thought to create an environment supporting nonconventional reactivity and exotic intermediates, such speculations have remained without proof. Here we use in situ, real-time powder X-ray diffraction monitoring to discover and capture a metastable, novel-topology intermediate of a mechanochemical transformation. Monitoring the mechanochemical synthesis of an archetypal metal-organic framework ZIF-8 by in situ powder X-ray diffraction reveals unexpected amorphization, and on further milling recrystallization into a non-porous material via a metastable intermediate based on a previously unreported topology, herein named katsenite (kat). The discovery of this phase and topology provides direct evidence that milling transformations can involve short-lived, structurally unusual phases not yet accessed by conventional chemistry.

  20. Reactive sputter magnetron reactor for preparation of thin films and simultaneous in situ structural study by X-ray diffraction.

    PubMed

    Bürgi, J; Neuenschwander, R; Kellermann, G; García Molleja, J; Craievich, A F; Feugeas, J

    2013-01-01

    The purpose of the designed reactor is (i) to obtain polycrystalline and∕or amorphous thin films by controlled deposition induced by a reactive sputtering magnetron and (ii) to perform a parallel in situ structural study of the deposited thin films by X-ray diffraction, in real time, during the whole growth process. The designed reactor allows for the control and precise variation of the relevant processing parameters, namely, magnetron target-to-sample distance, dc magnetron voltage, and nature of the gas mixture, gas pressure and temperature of the substrate. On the other hand, the chamber can be used in different X-ray diffraction scanning modes, namely, θ-2θ scanning, fixed α-2θ scanning, and also low angle techniques such as grazing incidence small angle X-ray scattering and X-ray reflectivity. The chamber was mounted on a standard four-circle diffractometer located in a synchrotron beam line and first used for a preliminary X-ray diffraction analysis of AlN thin films during their growth on the surface of a (100) silicon wafer. PMID:23387690

  1. Reactive sputter magnetron reactor for preparation of thin films and simultaneous in situ structural study by X-ray diffraction

    SciTech Connect

    Buergi, J.; Molleja, J. Garcia; Feugeas, J.; Neuenschwander, R.; Kellermann, G.; Craievich, A. F.

    2013-01-15

    The purpose of the designed reactor is (i) to obtain polycrystalline and/or amorphous thin films by controlled deposition induced by a reactive sputtering magnetron and (ii) to perform a parallel in situ structural study of the deposited thin films by X-ray diffraction, in real time, during the whole growth process. The designed reactor allows for the control and precise variation of the relevant processing parameters, namely, magnetron target-to-sample distance, dc magnetron voltage, and nature of the gas mixture, gas pressure and temperature of the substrate. On the other hand, the chamber can be used in different X-ray diffraction scanning modes, namely, {theta}-2{theta} scanning, fixed {alpha}-2{theta} scanning, and also low angle techniques such as grazing incidence small angle X-ray scattering and X-ray reflectivity. The chamber was mounted on a standard four-circle diffractometer located in a synchrotron beam line and first used for a preliminary X-ray diffraction analysis of AlN thin films during their growth on the surface of a (100) silicon wafer.

  2. High pressure and high temperature in situ X-ray diffraction studies in the Paris-Edinburgh cell using a laboratory X-ray source†

    NASA Astrophysics Data System (ADS)

    Toulemonde, Pierre; Goujon, Céline; Laversenne, Laetitia; Bordet, Pierre; Bruyère, Rémy; Legendre, Murielle; Leynaud, Olivier; Prat, Alain; Mezouar, Mohamed

    2014-04-01

    We have developed a new laboratory experimental set-up to study in situ the pressure-temperature phase diagram of a given pure element or compound, its associated phase transitions, or the chemical reactions involved at high pressure and high temperature (HP-HT) between different solids and liquids. This new tool allows laboratory studies before conducting further detailed experiments using more brilliant synchrotron X-ray sources or before kinetic studies. This device uses the diffraction of X-rays produced by a quasi-monochromatic micro-beam source operating at the silver radiation (λ(Ag)Kα 1, 2≈0.56 Å). The experimental set-up is based on a VX Paris-Edinburgh cell equipped with tungsten carbide or sintered diamond anvils and uses standard B-epoxy 5 or 7 mm gaskets. The diffracted signal coming from the compressed (and heated) sample is collected on an image plate. The pressure and temperature calibrations were performed by diffraction, using conventional calibrants (BN, NaCl and MgO) for determination of the pressure, and by crossing isochores of BN, NaCl, Cu or Au for the determination of the temperature. The first examples of studies performed with this new laboratory set-up are presented in the article: determination of the melting point of germanium and magnesium under HP-HT, synthesis of MgB2 or C-diamond and partial study of the P, T phase diagram of MgH2.

  3. In Situ X-ray Diffraction Studies of Li(sub x)Mn(sub 2)O(sub 4) Cathode Materials by Synchrotron X-ray Radiation

    SciTech Connect

    Yang, X. Q.; Sun, X.; Lee, S. J.; McBreen, J.; Mukerjee, S.; Daroux, M. L.; Xing, X. K.

    1998-11-01

    In Situ x-ray diffraction studies on Li{sub x}Mn{sub 2}O{sub 4} spinel cathode materials during charge-discharge cycles were carried out by using a synchrotron as x-ray source. Lithium rich (x = 1.03-1.06) spinel materials obtained from two different sources were studied. Three cubic phases with different lattice constants were observed during charge-discharge cycles in all the samples when a Sufficiently low charge-discharge rate (C/10) was used. There are two regions of two-phase coexistence between these three phases, indicating that both phase transitions are first order. The separation of the Bragg peaks representing these three phases varies from sample to sample and also depends on the charge-discharge rate. These results show that the de-intercalation of lithium in lithium-rich spinel cathode materials proceeds through a series of phase transitions from a lithium-rich phase to a lithium-poor phase and finally to a {lambda}-MnO{sub 2} like cubic phase, rather than through a continuous lattice constant contraction in a single phase.

  4. In situ flash x-ray high-speed computed tomography for the quantitative analysis of highly dynamic processes

    NASA Astrophysics Data System (ADS)

    Moser, Stefan; Nau, Siegfried; Salk, Manfred; Thoma, Klaus

    2014-02-01

    The in situ investigation of dynamic events, ranging from car crash to ballistics, often is key to the understanding of dynamic material behavior. In many cases the important processes and interactions happen on the scale of milli- to microseconds at speeds of 1000 m s-1 or more. Often, 3D information is necessary to fully capture and analyze all relevant effects. High-speed 3D-visualization techniques are thus required for the in situ analysis. 3D-capable optical high-speed methods often are impaired by luminous effects and dust, while flash x-ray based methods usually deliver only 2D data. In this paper, a novel 3D-capable flash x-ray based method, in situ flash x-ray high-speed computed tomography is presented. The method is capable of producing 3D reconstructions of high-speed processes based on an undersampled dataset consisting of only a few (typically 3 to 6) x-ray projections. The major challenges are identified, discussed and the chosen solution outlined. The application is illustrated with an exemplary application of a 1000 m s-1 high-speed impact event on the scale of microseconds. A quantitative analysis of the in situ measurement of the material fragments with a 3D reconstruction with 1 mm voxel size is presented and the results are discussed. The results show that the HSCT method allows gaining valuable visual and quantitative mechanical information for the understanding and interpretation of high-speed events.

  5. Kinetic Control of Metal–Organic Framework Crystallization Investigated by Time-Resolved In Situ X-Ray Scattering

    SciTech Connect

    Stavitski E.; Goesten M; Juan-Alcaniz J.; Martinez-Joaristi A.; Serra-Crespo P.; Petukhov A.; Gascon J.; Kapteijn F.

    2011-07-14

    The mechanism behind the multistep synthesis of two metal-organic frameworks sharing the same metal and organic precursors was revealed by in-situ time-resolved small- and wide-angle X-ray scattering. Key factors governing the crystal assembly could be established (see picture: C gray, H white, N blue, O red, Al yellow, Cl green), including solvent, temperature, and precursor concentration.

  6. Elemental analysis of human amniotic fluid and placenta by total-reflection X-ray fluorescence and energy-dispersive X-ray fluorescence: child weight and maternal age dependence

    NASA Astrophysics Data System (ADS)

    Carvalho, M. L.; Custódio, P. J.; Reus, U.; Prange, A.

    2001-11-01

    This work is an attempt to evaluate the possible influence of the mother's age in trace element concentrations in human amniotic fluid and placenta and whether these concentrations are correlated to the weight of the newborn infants. Total-reflection X-ray fluorescence (TXRF) was used to analyze 16 amniotic fluid samples, and the placenta samples were analyzed by energy dispersive X-ray fluorescence (EDXRF). The whole samples were collected during delivery from healthy mothers and healthy infants and full-term pregnancies. According to the age of the mother, three different groups were considered: 20-25, 25-30 and 30-40 years old. Only two mothers were aged more than 35 years. The weight of the infants ranged from 2.56 to 4.05 kg and three groups were also considered: 2.5-3, 3-3.5 and 3.5-4 kg. The organic matrix of the amniotic fluid samples was removed by treatment with HNO 3 followed by oxygen plasma ashing. Yttrium was used as the internal standard for TXRF analysis. Placenta samples were lyophilized and analyzed by EDXRF without any chemical treatment. Very low levels of Ni and Sr were found in the amniotic fluid samples, and were independent of the age of the mother and weight of the child. Cr, Mn, Se and Pb were at the level of the detection limit. Zn, considered one of the key elements in neonatal health, was not significantly different in the samples analyzed; however, it was weakly related to birth weigh. The concentrations obtained ranged from 0.11 to 0.92 mg/l and 30 to 65 μg/g in amniotic fluid and placenta, respectively. The only two elements which seemed to be significantly correlated with mother's age and newborn weight were Ca and Fe for both types of sample: Ca levels were increased in heavier children and older mothers; however, Fe increased with increasing maternal age, but decreased for heavier babies. The same conclusions were obtained for placenta and amniotic fluid samples. Cu is closely associated with Fe in its function in the organism

  7. Nondestructive characterization of municipal-solid-waste-contaminated surface soil by energy-dispersive X-ray fluorescence and low-Z (atomic number) particle electron probe X-ray microanalysis.

    PubMed

    Gupta, Dhrubajyoti; Ghosh, Rita; Mitra, Ajoy K; Roy, Subinit; Sarkar, Manoranjan; Chowdhury, Subhajit; Bhowmik, Asit; Mukhopadhyay, Ujjal; Maskey, Shila; Ro, Chul-Un

    2011-11-01

    The long-term environmental impact of municipal solid waste (MSW) landfilling is still under investigation due to the lack of detailed characterization studies. A MSW landfill site, popularly known as Dhapa, in the eastern fringe of the metropolis of Kolkata, India, is the subject of present study. A vast area of Dhapa, adjoining the current core MSW dump site and evolving from the raw MSW dumping in the past, is presently used for the cultivation of vegetables. The inorganic chemical characteristics of the MSW-contaminated Dhapa surface soil (covering a 2-km stretch of the area) along with a natural composite (geogenic) soil sample (from a small countryside farm), for comparison, were investigated using two complementary nondestructive analytical techniques, energy-dispersive X-ray fluorescence (EDXRF) for bulk analysis and low-Z (atomic number) particle electron probe X-ray microanalysis (low-Z particle EPMA) for single-particle analysis. The bulk concentrations of K, Rb, and Zr remain almost unchanged in all the soil samples. The Dhapa soil is found to be polluted with heavy metals such as Cu, Zn, and Pb (highly elevated) and Ti, Cr, Mn, Fe, Ni, and Sr (moderately elevated), compared to the natural countryside soil. These high bulk concentration levels of heavy metals were compared with the Ecological Soil Screening Levels for these elements (U.S. Environment Protection Agency) to assess the potential risk on the immediate biotic environment. Low-Z particle EPMA results showed that the aluminosilicate-containing particles were the most abundant, followed by SiO2, CaCO3-containing, and carbonaceous particles in the Dhapa samples, whereas in the countryside sample only aluminosilicate-containing and SiO2 particles were observed. The mineral particles encountered in the countryside sample are solely of geogenic origin, whereas those from the Dhapa samples seem to have evolved from a mixture of raw dumped MSW, urban dust, and other contributing factors such as wind

  8. X-ray photochemical alteration of planetary samples during in situ micro-XRF analysis

    NASA Astrophysics Data System (ADS)

    Flannery, D. T.; Tuite, M. L., Jr.; Hodyss, R. P.; Allwood, A.; Bhartia, R.; Abbey, W. J.; Williford, K. H.

    2015-12-01

    PIXL (Planetary Instrument for X-ray Lithochemistry; selected for the Mars 2020 mission contact science payload) uses a polycapillary to focus X-rays to a ~100 μm spot on sample surfaces, providing higher spatial resolution, higher X-ray flux, and higher fluorescence counts compared to previously flown planetary XRF instruments. Photochemical changes in organic materials occurring during investigations employing x-rays have been reported, particularly for biological samples examined in synchrotrons (e.g. George et al., J. Synchrotron Radiation, 19:875-876). However, little is known about the effect energies and fluxes typical to micro-XRF instruments may have on the organic molecules that are commonly preserved in rocks and sediments. In particular, it is essential to understand the effect of micro-XRF on organics preserved near surfaces that are later subjected to contact science that focuses on organic geochemistry (e.g. UV Raman/fluorescence instruments). We report results of an investigation in which samples containing organic molecules were exposed to X-ray energies and fluxes typical to micro-XRF. Samples containing alkanes and polycyclic aromatic hydrocarbons were characterized by GC-MS and UV Raman/fluorescence before being subjected to various X-ray energies and fluxes typical of PIXL. Following x-ray irradiation, samples were again characterized by GC-MS and UV Raman/fluorescence in order to characterize photochemical effects.

  9. Direct in situ observation of ZnO nucleation and growth via transmission X-ray microscopy.

    PubMed

    Tay, S E R; Goode, A E; Nelson Weker, J; Cruickshank, A A; Heutz, S; Porter, A E; Ryan, M P; Toney, M F

    2016-01-28

    The nucleation and growth of a nanostructure controls its size and morphology, and ultimately its functional properties. Hence it is crucial to investigate growth mechanisms under relevant growth conditions at the nanometer length scale. Here we image the nucleation and growth of electrodeposited ZnO nanostructures in situ, using a transmission X-ray microscope and specially designed electrochemical cell. We show that this imaging technique leads to new insights into the nucleation and growth mechanisms in electrodeposited ZnO including direct, in situ observations of instantaneous versus delayed nucleation. PMID:26738407

  10. Structure and growth of stearate monolayers on calcite: First results of an in situ X-ray reflectivity study

    SciTech Connect

    Fenter, P.; Sturchio, N.C.

    1999-10-01

    The adsorption of organic molecules at mineral-fluid interfaces has a profound influence upon geochemical reaction and transport processes, yet little is known about the in situ structures or properties of organic layers at mineral-fluid interfaces. The authors describe an X-ray reflectivity study of stearate monolayers adsorbed at the calcite surface from methanolic solutions. Using these measurements the authors are able to determine important aspects of the in situ structure, bonding, adsorption, and growth mechanisms of stearate monolayers. The experimental approach demonstrated here can be applied widely in studying the interaction of organic molecules with mineral surfaces in aqueous systems.

  11. Automatic Peak Identification in Scanning Electron Microscopy/Energy Dispersive X-ray (SEM/EDS) Microanalysis: Can You Always Trust the Results?

    NASA Astrophysics Data System (ADS)

    Newbury, D.

    2006-05-01

    The degree of sophistication of computer-aided scanning electron microscopy/energy dispersive x-ray spectrometry (SEM/EDS) microanalysis has advanced to the point where it is possible with a single command to automatically perform sequential qualitative analysis (peak identification) and quantitative analysis and then create a report of analysis with full statistical support. Often the actual algorithms employed in commercial software for each stage of the analysis are not provided or tested in sufficient detail nor are any inherent limitations in applying such "black box" software described to enable the analyst to estimate the performance. The identification of the elements responsible for the characteristic peaks in the EDS spectrum is obviously the first critical step in performing a robust analysis. Can the software be trusted to always deliver the correct elemental identification for the easiest possible case: peaks with high intensity and high peak-to-background that arise from major constituents (i.e., concentration, C above 0.1 mass fraction = 10 weight percent) and which do not suffer peak interference from another constituent? Unfortunately, testing of automatic peak identification procedures in a series of commercial systems has revealed that serious mistakes occur approximately 3 to 5 percent of the time for this easiest case [1]. Moreover, these mistakes are not random but occur systematically for certain elements. The situation is even worse when minor (C from 0.01 to 0.1) and trace (C less than 0.01) constituents are of interest or when analysis is performed under "low voltage" conditions (beam energy 5 keV or less). The prudent analyst will always use manual peak identification procedures to provide confirmation of automatic peak identification results before proceeding to quantitative analysis [2]. [1] Newbury, D., Microscopy and Microanalysis, 11 (2005) 545. [2] Goldstein, J., Newbury, D., Joy, D., Lyman, C., Echlin, P., Lifshin, E., Sawyer, L

  12. Development of a Compact System for In-situ X-ray Scattering Studies of Organic Thin Film Deposition

    SciTech Connect

    Headrick, R.L.; Malliaras, G.G.; Mayer, A.C.; Deyhim, A.K.; Hunt, A.C.

    2004-05-12

    We have developed a compact vacuum deposition chamber for in-situ x-ray scattering studies of organic thin film growth. The system is based on a small cylindrical chamber that can be mounted on a standard four-circle diffractometer. Incident and scattered x-rays enter and exit the chamber through a curved Be foil window that covers 200 degrees, and is sealed to the body of the chamber. The sample is mounted on a support tube with heating and cooling from liquid nitrogen temperature to >100 deg. C. Integral to the sample stage is a multi-wire feedthrough to facilitate in-situ electrical transport characterization of organic semiconductor thin films. This is one of the novel capabilities of the system. In addition, the sample stage is mounted on a rotary vacuum feedthrough, which is mechanically coupled to the 'phi' stage of the diffractometer. An effusion cell, shutter, and quartz oscillator thickness monitor are also incorporated into the system, which is pumped by a small turbomolecular pump. The system thus configured is capable of access to full reciprocal space, within the limits of the Be window. Results of initial experiments performed at the 48-pole wiggler beamline A2, at the Cornell High Energy Synchrotron Source show that in-situ x-ray scattering is sensitive to the early stages of nucleation and growth of organic semiconductor thin films.

  13. In situ X-ray powder diffraction, synthesis, and magnetic properties of InVO{sub 3}

    SciTech Connect

    Lundgren, Rylan J.; Cranswick, Lachlan M.D.; Bieringer, Mario . E-mail: Mario_Bieringer@umanitoba.ca

    2006-12-15

    We report the first synthesis and high-temperature in situ X-ray diffraction study of InVO{sub 3}. Polycrystalline InVO{sub 3} has been prepared via reduction of InVO{sub 4} using a carbon monoxide/carbon dioxide buffer gas. InVO{sub 3} crystallizes in the bixbyite structure in space group Ia-3 (206) with a=9.80636(31) A with In{sup 3+}/V{sup 3+} disorder on the (8b) and (24d) cation sites. In situ powder X-ray diffraction experiments and thermal gravimetric analysis in a CO/CO{sub 2} buffer gas revealed the existence of the metastable phase InVO{sub 3}. Bulk samples with 98.5(2)% purity were prepared using low-temperature reduction methods. The preparative methods limited the crystallinity of this new phase to approximately 225(50) A. Magnetic susceptibility and neutron diffraction experiments suggest a spin-glass ground state for InVO{sub 3}. - Graphical abstract: In situ powder X-ray diffractograms for the reduction of InVO{sub 4} in CO/CO{sub 2}. The three temperature regions show the conversion of InVO{sub 4} to InVO{sub 3} and final decomposition into In{sub 2}O{sub 3} and V{sub 2}O{sub 3}.

  14. In Situ Ptychography of Heterogeneous Catalysts using Hard X-Rays: High Resolution Imaging at Ambient Pressure and Elevated Temperature.

    PubMed

    Baier, Sina; Damsgaard, Christian D; Scholz, Maria; Benzi, Federico; Rochet, Amélie; Hoppe, Robert; Scherer, Torsten; Shi, Junjie; Wittstock, Arne; Weinhausen, Britta; Wagner, Jakob B; Schroer, Christian G; Grunwaldt, Jan-Dierk

    2016-02-01

    A new closed cell is presented for in situ X-ray ptychography which allows studies under gas flow and at elevated temperature. In order to gain complementary information by transmission and scanning electron microscopy, the cell makes use of a Protochips E-chipTM which contains a small, thin electron transparent window and allows heating. Two gold-based systems, 50 nm gold particles and nanoporous gold as a relevant catalyst sample, were used for studying the feasibility of the cell. Measurements showing a resolution around 40 nm have been achieved under a flow of synthetic air and during heating up to temperatures of 933 K. An elevated temperature exhibited little influence on image quality and resolution. With this study, the potential of in situ hard X-ray ptychography for investigating annealing processes of real catalyst samples is demonstrated. Furthermore, the possibility to use the same sample holder for ex situ electron microscopy before and after the in situ study underlines the unique possibilities available with this combination of electron microscopy and X-ray microscopy on the same sample. PMID:26914998

  15. {ital In-situ} x-ray investigation of hydrogen charging in thin film bimetallic electrodes

    SciTech Connect

    Jisrawi, N.M.; Wiesmann, H.; Ruckman, M.W.; Thurston, T.R.; Reisfeld, G.; Ocko, B.M.; Strongin, M.

    1997-08-01

    Hydrogen uptake and discharge by thin metallic films under potentiostatic control was studied using x-ray diffraction at the National Synchrotron Light Source (NSLS). The formation of metal-hydrogen phases in Pd, Pd-capped Nb and Pd/Nb multilayer electrode structures was deduced from x-ray diffraction data and correlated with the cyclic voltammetry (CV) peaks. The x-ray data was also used to construct a plot of the hydrogen concentration as a function of cell potential for a multilayered thin film. {copyright} {ital 1997 Materials Research Society.}

  16. The effect of silica on polymorphic precipitation of calcium carbonate: an on-line energy-dispersive X-ray diffraction (EDXRD) study

    NASA Astrophysics Data System (ADS)

    Kellermeier, Matthias; Glaab, Fabian; Klein, Regina; Melero-García, Emilio; Kunz, Werner; García-Ruiz, Juan Manuel

    2013-07-01

    Calcium carbonate is the most abundant biomineral and a compound of great industrial importance. Its precipitation from solution has been studied extensively and was often shown to proceed via distinct intermediate phases, which undergo sequential transformations before eventually yielding the stable crystalline polymorph, calcite. In the present work, we have investigated the crystallisation of calcium carbonate in a time-resolved and non-invasive manner by means of energy-dispersive X-ray diffraction (EDXRD) using synchrotron radiation. In particular, the role of silica as a soluble additive during the crystallisation process was examined. Measurements were carried out at different temperatures (20, 50 and 80 °C) and various silica concentrations. Experiments conducted in the absence of silica reflect the continuous conversion of kinetically formed metastable polymorphs (vaterite and aragonite) to calcite and allow for quantifying the progress of transformation. Addition of silica induced remarkable changes in the temporal evolution of polymorphic fractions existing in the system. Essentially, the formation of calcite was found to be accelerated at 20 °C, whereas marked retardation or complete inhibition of phase transitions was observed at higher temperatures. These findings are explained in terms of a competition between the promotional effect of silica on calcite growth rates and kinetic stabilisation of vaterite and aragonite due to adsorption (or precipitation) of silica on their surfaces, along with temperature-dependent variations of silica condensation rates. Data collected at high silica concentrations indicate the presence of an amorphous phase over extended frames of time, suggesting that initially generated ACC particles are progressively stabilised by silica. Our results may have important implications for CaCO3 precipitation scenarios in both geochemical and industrial settings, where solution silicate is omnipresent, as well as for CO2

  17. Development of a new Planetary SCD-based X-Ray Fluorescence Spectrometer Package for in-situ Analysis

    NASA Astrophysics Data System (ADS)

    Fabel, Oliver; Köhler, Eberhard; Dreißigacker, Anne; Meyer, Matthias; van Gasselt, Stephan

    2014-05-01

    We propose an X-Ray Fluorescence Instrument Package (XRF-X and XRF-ISM) in order to measure the composition of rock-surface materials from orbiter, lander, and rover-based systems directly and quantitatively. It is suited for all future missions to the Moon, but also to the Galilean Satellites or any other solid-surface solar system body without an atmosphere. Collected data will be used for constructing detailed geochemical maps of the target body's surface composition. The typical spectral range is 1 - 10 keV (1.2 - 0.12 nm) with no sharp limits, achieving a spectral resolution of 160 eV at 6 keV. At these conditions, elemental abundances of lighter elements (atomic no. 11-32, K-Lines) and heavier elements (atomic no. 33-80, L-lines) will be observable. This will allow for mapping concentrations of the main mineral- (and therefore rock-) forming elements of surface materials, in particular Na, Mg, Al, Si, K, Ca, Ti, Mn, and Fe. The spatial resolution (GSD) is 10 km/px at an orbit altitude of 50 km. The package consists of two subsystems: (1) the main instrument targeting at a body's surface (XRF-X), and (2) a zenith-pointing solar monitor which incorporates calibration targets for taking account of solar X-Rays and particles (XRF-ISM). Both instruments make use of Energy-Dispersive X-Ray Fluorescence (EDX) with solar X-Ray excitation to probe materials over arbitrary distances. By monitoring incident Solar X-Ray and potential particle flux through synchronous measurement of a calibration target, XRF-X measurements can be obtained even over long distances, e.g. from a lunar orbiter. A scalable and modular design allows for instrument adaptions to desired resolution, to weight and power-consumption constraints and to expected sun emission intensities. The design will also allow adaption for employment on different observation platforms. In the current laboratory setup, both experiments are developed using large-area swept charge devices (SCD) to allow for high X-Ray

  18. Determination of heavy metals concentrations in airborne particulates matter (APM) from Manjung district, Perak using energy dispersive X-ray fluorescence (EDXRF) spectrometer

    NASA Astrophysics Data System (ADS)

    Arshad, Nursyairah; Hamzah, Zaini; Wood, Ab. Khalik; Saat, Ahmad; Alias, Masitah

    2015-04-01

    Airborne particulates trace metals are considered as public health concern as it can enter human lungs through respiratory system. Generally, any substance that has been introduced to the atmosphere that can cause severe effects to living things and the environment is considered air pollution. Manjung, Perak is one of the development districts that is active with industrial activities. There are many industrial activities surrounding Manjung District area such as coal fired power plant, quarries and iron smelting which may contribute to the air pollution into the environment. This study was done to measure the concentrations of Hg, U, Th, K, Cu, Fe, Cr, Zn, As, Se, Pb and Cd in the Airborne Particulate Matter (APM) collected at nine locations in Manjung District area within 15 km radius towards three directions (North, North-East and South-East) in 5 km intervals. The samples were collected using mini volume air sampler with cellulose filter through total suspended particulate (TSP). The sampler was set up for eight hours with the flow rate of 5 L/min. The filter was weighed before and after sample collection using microbalance, to get the amount of APM and kept in desiccator before analyzing. The measurement was done using calibrated Energy Dispersive X-Ray Fluorescence (EDXRF) Spectrometer. The air particulate concentrations were found below the Malaysia Air Quality Guidelines for TSP (260 µg/m3). All of the metals concentrations were also lower than the guidelines set by World Health Organization (WHO), Ontario Ministry of the Environment and Argonne National Laboratory, USA NCRP (1975). From the concentrations, the enrichment factor were calculated.

  19. Quantitative determinations and imaging in different structures of buried human bones from the XVIII-XIXth centuries by energy dispersive X-ray fluorescence - Postmortem evaluation.

    PubMed

    Guimarães, D; Dias, A A; Carvalho, M; Carvalho, M L; Santos, J P; Henriques, F R; Curate, F; Pessanha, S

    2016-08-01

    In this work, a non-commercial triaxial geometry energy dispersive X-ray Fluorescence (EDXRF) setup and a benchtop µ-XRF system were used to identify postmortem contamination in buried bones. For two of the individuals, unusually high concentrations of Cu and Pb, but also Zn (in one individual) were observed. The pigments of the burial shroud coverings have been identified as the source of contamination. Accurate and precise quantitative results were obtained by nondestructive process using fundamental parameters method taking into account the matrix absorption effects. A total of 30 bones from 13 individuals, buried between the mid-XVIIIth to early XIXth centuries, were analyzed to study the elemental composition and elemental distribution. The bones were collected from a church in Almada (Portugal), called Ermida do Espírito Santo, located near the Tagus River and at the sea neighbourhood. The triaxial geometry setup was used to quantify Ca, Fe, Cu, Zn, Br, Sr and Pb of powder pressed bone pellets (n=9 for each bone). Cluster analysis was performed considering the elemental concentrations for the different bones. There was a clear association between some bones regarding Fe, Cu, Zn, Br and Pb content but not a categorization between cortical and trabecular bones. The elemental distribution of Cu, Zn and Pb were assessed by the benchtop μ-analysis, the M4 Tornado, based on a polycapillary system which provides multi-elemental 2D maps. The results showed that contamination was mostly on the surface of the bone confirming that it was related to the burial shroud covering the individuals. PMID:27216663

  20. Silicon supported lipid-DNA thin film structures at varying temperature studied by energy dispersive X-ray diffraction and neutron reflectivity.

    PubMed

    Domenici, F; Castellano, C; Dell'Unto, F; Albinati, A; Congiu, A

    2011-11-01

    Non-viral gene transfection by means of lipid-based nanosystems, such as solid supported lipid assemblies, is often limited due to their lack of stability and the consequent loss of efficiency. Therefore not only a detailed thermo-lyotropic study of these DNA-lipid complexes is necessary to understand their interaction mechanisms, but it can also be considered as a first step in conceiving and developing new transfection biosystems. The aim of our study is a structural characterization of 1,2-dioleoyl-sn-glycero-3-phosphatidylcholine (DOPC)-dimethyl-dioctadecyl-ammonium bromide (DDAB)-DNA complex at varying temperature using the energy dispersive X-ray diffraction (EDXD) and neutron reflectivity (NR) techniques. We have shown the formation of a novel thermo-lyotropic structure of DOPC/DDAB thin film self-organized in multi-lamellar planes on (100)-oriented silicon support by spin coating, thus enlightening its ability to include DNA strands. Our NR measurements indicate that the DOPC/DDAB/DNA complex forms temperature-dependent structures. At 65°C and relative humidity of 100% DNA fragments are buried between single lamellar leaflets constituting the hydrocarbon core of the lipid bilayers. This finding supports the consistency of the hydrophobic interaction model, which implies that the coupling between lipid tails and hypo-hydrated DNA single strands could be the driving force of DNA-lipid complexation. Upon cooling to 25°C, EDXD analysis points out that full-hydrated DOPC-DDAB-DNA can switch in a different metastable complex supposed to be driven by lipid heads-DNA electrostatic interaction. Thermotropic response analysis also clarifies that DOPC has a pivotal role in promoting the formation of our observed thermophylic silicon supported lipids-DNA assembly. PMID:21816578

  1. Structural behavior of palladium (II) oxide and a palladium suboxide at high pressure: An energy-dispersive x-ray-diffraction study

    NASA Astrophysics Data System (ADS)

    Christy, Andrew G.; Clark, Simon M.

    1995-10-01

    The behavior of PdO at high pressure was studied by energy-dispersive x-ray diffraction of samples contained in diamond anvil cells. PdO undergoes a first-order transition at about 12 GPa. The new phase is tetragonal and of similar cell dimensions to the low-pressure phase. However, it is more compressible along c and much harder along a. The volume change is 1.7%. It is likely that the new phase has the rocksalt structure, tetragonally elongated due to the low-spin d8 electron configuration of palladium (II). The zero-pressure cell parameters and bulk moduli are (low pressure phase) a=3.042(1) Å, c=5.351(3) Å, K=280+/-52 GPa; (high pressure phase) a=2.982 Å, c=5.383 Å, K=545+/-20 GPa. One sample prepared was found to be a mixture of PdO with a cubic material [Fm3m, a=4.043(5) Å at ambient], deduced to be a suboxide PdOx with x approximately 0.21-0.27. Under pressure, the two phases reacted reversibly: PdO was consumed and x increased with increasing pressure. This led to expansion of the suboxide unit cell with pressure up to 1.73 GPa, above which pressure the calculated value of x remained approximately constant and the lattice constant decreased in the usual fashion. It is evidently possible to construct mixtures of these two phases which show zero total change in the lattice constant of the cubic phase over a selected range of pressure.

  2. Orthogonal identification of gunshot residue with complementary detection principles of voltammetry, scanning electron microscopy, and energy-dispersive X-ray spectroscopy: sample, screen, and confirm.

    PubMed

    O'Mahony, Aoife M; Samek, Izabela A; Sattayasamitsathit, Sirilak; Wang, Joseph

    2014-08-19

    Field-deployable voltammetric screening coupled with complementary laboratory-based analysis to confirm the presence of gunshot residue (GSR) from the hands of a subject who has handled, loaded, or discharged a firearm is described. This protocol implements the orthogonal identification of the presence of GSR utilizing square-wave stripping voltammetry (SWSV) as a rapid screening tool along with scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) to confirm the presence of the characteristic morphology and metal composition of GSR particles. This is achieved through the judicious modification of the working electrode of a carbon screen-printed electrode (CSPE) with carbon tape (used in SEM analysis) to fix and retain a sample. A comparison between a subject who has handled and loaded a firearm and a subject who has had no contact with GSR shows the significant variations in voltammetric signals and the presence or absence of GSR-consistent particles and constituent metals. This initial electrochemical screening has no effect on the integrity of the metallic particles, and SEM/EDX analysis conducted prior to and postvoltammetry show no differences in analytical output. The carbon tape is instrumental in retaining the GSR sample after electrochemical analysis, supported by comparison with orthogonal detection at a bare CSPE. This protocol shows great promise as a two-tier detection system for the presence of GSR from the hands of a subject, whereby initial screening can be conducted rapidly onsite by minimally trained operators; confirmation can follow at the same substrate to substantiate the voltammetric results. PMID:25084547

  3. Time-resolved and in-situ X-ray scattering methods beyond photoactivation: Utilizing high-flux X-ray sources for the study of ubiquitous non-photoactive proteins.

    PubMed

    Jain, Rohit; Techert, Simone

    2016-01-01

    X-ray scattering technique, comprising of small-angle/wide-angle X-ray scattering (SAXS/WAXS) techniques is increasingly used to characterize the structure and interactions of biological macromolecules and their complexes in solution. It is a method of choice to characterize the flexible, partially folded and unfolded protein systems. X-ray scattering is the last resort for proteins that cannot be investigated by crystallography or NMR and acts as a complementary technique with different biophysical techniques to answer challenging scientific questions. The marriage of the X-ray scattering technique with the fourth dimension "time" yields structural dynamics and kinetics information for protein motions in hierarchical timescales from picoseconds to days. The arrival of the high-flux X-ray beam at third generation synchrotron sources, exceptional X-ray optics, state-of-the-art detectors, upgradation of X-ray scattering beamlines with microfluidics devices and advanced X-ray scattering data analysis procedures are the important reasons behind the shining years of X-ray scattering technique. The best days of the X-ray scattering technique are on the horizon with the advent of the nanofocus X-ray scattering beamlines and fourth generation X-ray lightsources, i.e., free electron lasers (XFELs). Complementary to the photon-triggered time-resolved X-ray scattering techniques, we will present an overview of the time-resolved and in-situ X-ray scattering techniques for structural dynamics of ubiquitous non-photoactive proteins. PMID:26732244

  4. Direct in situ observation of ZnO nucleation and growth via transmission X-ray microscopy

    NASA Astrophysics Data System (ADS)

    Tay, S. E. R.; Goode, A. E.; Nelson Weker, J.; Cruickshank, A. A.; Heutz, S.; Porter, A. E.; Ryan, M. P.; Toney, M. F.

    2016-01-01

    The nucleation and growth of a nanostructure controls its size and morphology, and ultimately its functional properties. Hence it is crucial to investigate growth mechanisms under relevant growth conditions at the nanometer length scale. Here we image the nucleation and growth of electrodeposited ZnO nanostructures in situ, using a transmission X-ray microscope and specially designed electrochemical cell. We show that this imaging technique leads to new insights into the nucleation and growth mechanisms in electrodeposited ZnO including direct, in situ observations of instantaneous versus delayed nucleation.The nucleation and growth of a nanostructure controls its size and morphology, and ultimately its functional properties. Hence it is crucial to investigate growth mechanisms under relevant growth conditions at the nanometer length scale. Here we image the nucleation and growth of electrodeposited ZnO nanostructures in situ, using a transmission X-ray microscope and specially designed electrochemical cell. We show that this imaging technique leads to new insights into the nucleation and growth mechanisms in electrodeposited ZnO including direct, in situ observations of instantaneous versus delayed nucleation. Electronic supplementary information (ESI) available: Methods and videos of nanoparticle growth. See DOI: 10.1039/c5nr07019h

  5. In-Situ X-Ray Microscopy of Phase and Composition Distributions in Metal Alloys During Solidification

    NASA Technical Reports Server (NTRS)

    Kaukler, William F.; Curreri, Peter A.

    1999-01-01

    This research applies a state of the art X-ray Transmission Microscope, to image the solidification of metallic or semiconductor alloys in real-time. By employing a hard x-ray source with sub-micron dimensions, resolutions of up to 3 gm can be obtained with magnifications of over 800 X. Specimen growth conditions were optimized and the best imaging technologies applied to maintain x-ray image resolution, contrast and sensitivity. In addition, a special furnace design is required to permit controlled growth conditions and still offer maximum resolution and image contrast. We have successfully imaged in real-time: interfacial morphologies, phase growth, coalescence, incorporation of phases into the growing interface, and the solute boundary layer in the liquid at the solid-liquid inter-face. We have also measured true local growth rates and can evaluate segregation structures in the solid; a form of in-situ metallography. Composition gradients within the specimen cause vafiations in absorption of the flux such that the final image represents a spatial integral of composition (or thickness). During this study, the growth of secondary phase fibers and lameilae from eutectic and monotectic alloys have been imaged during solidification, in real-time, for the first time in bulk metal alloys. Keywords: x-ray, microscope, solidification, microfocus, real-time, microstructure

  6. X-ray irradiation of soda-lime glasses studied in situ with surface plasmon resonance spectroscopy

    NASA Astrophysics Data System (ADS)

    Serrano, A.; Gálvez, F.; Rodríguez de la Fuente, O.; García, M. A.

    2013-03-01

    We present here a study of hard X-ray irradiation of soda-lime glasses performed in situ and in real time. For this purpose, we have used a Au thin film grown on glass and studied the excitation of its surface plasmon resonance (SPR) while irradiating the sample with X-rays, using a recently developed experimental setup at a synchrotron beamline [Serrano et al., Rev. Sci. Instrum. 83, 083101 (2012)]. The extreme sensitivity of the SPR to the features of the glass substrate allows probing the modifications caused by the X-rays. Irradiation induces color centers in the soda-lime glass, modifying its refractive index. Comparison of the experimental results with simulated data shows that both, the real and the imaginary parts of the refractive index of soda-lime glasses, change upon irradiation in time intervals of a few minutes. After X-ray irradiation, the effects are partially reversible. The defects responsible for these modifications are identified as non-bridging oxygen hole centers, which fade by recombination with electrons after irradiation. The kinetics of the defect formation and fading process are also studied in real time.

  7. X-ray irradiation of soda-lime glasses studied in situ with surface plasmon resonance spectroscopy

    SciTech Connect

    Serrano, A.; Galvez, F.; Rodriguez de la Fuente, O.; Garcia, M. A.

    2013-03-21

    We present here a study of hard X-ray irradiation of soda-lime glasses performed in situ and in real time. For this purpose, we have used a Au thin film grown on glass and studied the excitation of its surface plasmon resonance (SPR) while irradiating the sample with X-rays, using a recently developed experimental setup at a synchrotron beamline [Serrano et al., Rev. Sci. Instrum. 83, 083101 (2012)]. The extreme sensitivity of the SPR to the features of the glass substrate allows probing the modifications caused by the X-rays. Irradiation induces color centers in the soda-lime glass, modifying its refractive index. Comparison of the experimental results with simulated data shows that both, the real and the imaginary parts of the refractive index of soda-lime glasses, change upon irradiation in time intervals of a few minutes. After X-ray irradiation, the effects are partially reversible. The defects responsible for these modifications are identified as non-bridging oxygen hole centers, which fade by recombination with electrons after irradiation. The kinetics of the defect formation and fading process are also studied in real time.

  8. Determination of the solubility of tin indium oxide using in situ and ex x-ray diffraction

    SciTech Connect

    Gonzalez, G. B.; Mason, T. O.; Okasinski, J. S.; Buslaps, T.; Honkimaki, V.

    2012-02-01

    A novel approach to determine the thermodynamic solubility of tin in indium oxide via the exsolution from tin overdoped nano-ITO powders is presented. High-energy, in situ and ex situ synchrotron X-ray diffraction was utilized to study the solubility limit at temperatures ranging from 900 C to 1375 C. The tin exsolution from overdoped nanopowders and the formation of In{sub 4}Sn{sub 3}O{sub 12} were observed in situ during the first 4-48 h of high-temperature treatment. Samples annealed between 900 C and 1175 C were also studied ex situ with heat treatments for up to 2060 h. Structural results obtained from Rietveld analysis include compositional phase analysis, atomic positions, and lattice parameters. The tin solubility in In{sub 2}O{sub 3} was determined using the phase analysis compositions from X-ray diffraction and the elemental compositions obtained from X-ray fluorescence. Experimental complications that can lead to incorrect tin solubility values in the literature are discussed.

  9. A Next-Generation Hard X-Ray Nanoprobe Beamline for In Situ Studies of Energy Materials and Devices

    NASA Astrophysics Data System (ADS)

    Maser, Jörg; Lai, Barry; Buonassisi, Tonio; Cai, Zhonghou; Chen, Si; Finney, Lydia; Gleber, Sophie-Charlotte; Jacobsen, Chris; Preissner, Curt; Roehrig, Chris; Rose, Volker; Shu, Deming; Vine, David; Vogt, Stefan

    2014-01-01

    The Advanced Photon Source is developing a suite of new X-ray beamlines to study materials and devices across many length scales and under real conditions. One of the flagship beamlines of the APS upgrade is the In Situ Nanoprobe (ISN) beamline, which will provide in situ and operando characterization of advanced energy materials and devices under varying temperatures, gas ambients, and applied fields, at previously unavailable spatial resolution and throughput. Examples of materials systems include inorganic and organic photovoltaic systems, advanced battery systems, fuel cell components, nanoelectronic devices, advanced building materials and other scientifically and technologically relevant systems. To characterize these systems at very high spatial resolution and trace sensitivity, the ISN will use both nanofocusing mirrors and diffractive optics to achieve spots sizes as small as 20 nm. Nanofocusing mirrors in Kirkpatrick-Baez geometry will provide several orders of magnitude increase in photon flux at a spatial resolution of 50 nm. Diffractive optics such as zone plates and/or multilayer Laue lenses will provide a highest spatial resolution of 20 nm. Coherent diffraction methods will be used to study even small specimen features with sub-10 nm relevant length scale. A high-throughput data acquisition system will be employed to significantly increase operations efficiency and usability of the instrument. The ISN will provide full spectroscopy capabilities to study the chemical state of most materials in the periodic table, and enable X-ray fluorescence tomography. In situ electrical characterization will enable operando studies of energy and electronic devices such as photovoltaic systems and batteries. We describe the optical concept for the ISN beamline, the technical design, and the approach for enabling a broad variety of in situ studies. We furthermore discuss the application of hard X-ray microscopy to study defects in multi-crystalline solar cells, one

  10. A Next-Generation Hard X-Ray Nanoprobe Beamline for In Situ Studies of Energy Materials and Devices

    SciTech Connect

    Maser, Jong; Lai, Barry; Buonassisi, Toni; Cai, Zhonghou; Chen, Si; Finney, Lydia; Gleber, Sophie-Charlotte; Jacobsen, Chris; Preissner, Curt; Chris Roehrig; Rose, Volker; Shu, Deming; Vine, David; Vogt, Stefan

    2013-08-20

    The Advanced Photon Source is developing a suite of new X-ray beamlines to study materials and devices across many length scales and under real conditions. One of the flagship beamlines of the APS upgrade is the In Situ Nanoprobe (ISN) beamline, which will provide in situ and operando characterization of advanced energy materials and devices under varying temperatures, gas ambients, and applied fields, at previously unavailable spatial resolution and throughput. Examples of materials systems include inorganic and organic photovoltaic systems, advanced battery systems, fuel cell components, nanoelectronic devices, advanced building materials and other scientifically and technologically relevant systems. To characterize these systems at very high spatial resolution and trace sensitivity, the ISN will use both nanofocusing mirrors and diffractive optics to achieve spots sizes as small as 20 nm. Nanofocusing mirrors in Kirkpatrick–Baez geometry will provide several orders of magnitude increase in photon flux at a spatial resolution of 50 nm. Diffractive optics such as zone plates and/or multilayer Laue lenses will provide a highest spatial resolution of 20 nm. Coherent diffraction methods will be used to study even small specimen features with sub-10 nm relevant length scale. A high-throughput data acquisition system will be employed to significantly increase operations efficiency and usability of the instrument. The ISN will provide full spectroscopy capabilities to study the chemical state of most materials in the periodic table, and enable X-ray fluorescence tomography. In situ electrical characterization will enable operando studies of energy and electronic devices such as photovoltaic systems and batteries. We also describe the optical concept for the ISN beamline, the technical design, and the approach for enabling a broad variety of in situ studies. Furthermore, we discuss the application of hard X-ray microscopy to study defects in multi-crystalline solar

  11. An ultra-high vacuum electrochemical flow cell for in situ/operando soft X-ray spectroscopy study

    SciTech Connect

    Bora, Debajeet K. E-mail: jguo@lbl.gov; Glans, Per-Anders; Pepper, John; Liu, Yi-Sheng; Guo, J.-H. E-mail: jguo@lbl.gov; Du, Chun; Wang, Dunwei

    2014-04-15

    An in situ flow electrochemical cell has been designed and fabricated to allow better seal under UHV chamber thus to achieve a good signal to noise ratio in fluorescence yield detection of X-ray absorption spectra for spectroelectrochemical study. The cell also stabilizes the thin silicon nitride membrane window in an effective manner so that the liquid cell remains intact during X-ray absorption experiments. With the improved design of the liquid cell, electrochemical experiments such as cyclic voltammetry have been performed for 10 cycles with a good stability of sample window. Also an operando electrochemical experiment during photoelectrochemistry has been performed on n-type hematite electrode deposited on silicon nitride window. The experiment allows us to observe the formation of two extra electronic transitions before pre edge of O K-edge spectra.

  12. Novel Cell Design for Combined In Situ Acoustic Emission and X-ray Diffraction of Cycling Lithium Ion Batteries

    SciTech Connect

    Rhodes, Kevin J; Kirkham, Melanie J; Meisner, Roberta Ann; Parish, Chad M; Dudney, Nancy J; Daniel, Claus

    2011-01-01

    An in situ acoustic emission (AE) and X-ray diffraction (XRD) cell for use in the study of battery electrode materials has been devised and tested. This cell uses commercially available coin cell hardware retrofitted with a metalized polyethylene terephthalate (PET) disk which acts as both an X-ray window and a current collector. In this manner the use of beryllium and its associated cost and hazard is avoided. An AE sensor may be affixed to the cell face opposite the PET window in order to monitor degradation effects, such as particle fracture, during cell cycling. Silicon particles which were previously studied by the AE technique were tested in this cell as a model material. The performance of these cells compared well with unmodified coin cells while providing information about structural changes in the active material as the cell is repeatedly charged and discharged.

  13. Novel cell design for combined in situ acoustic emission and x-ray diffraction study during electrochemical cycling of batteries

    SciTech Connect

    Rhodes, Kevin; Meisner, Roberta; Daniel, Claus; Kirkham, Melanie; Parish, Chad M.; Dudney, Nancy

    2011-07-15

    An in situ acoustic emission (AE) and x-ray diffraction cell for use in the study of battery electrode materials has been designed and tested. This cell uses commercially available coin cell hardware retrofitted with a metalized polyethylene terephthalate (PET) disk, which acts as both an x-ray window and a current collector. In this manner, the use of beryllium and its associated cost and hazards is avoided. An AE sensor may be affixed to the cell face opposite the PET window in order to monitor degradation effects, such as particle fracture, during cell cycling. Silicon particles, which were previously studied by the AE technique, were tested in this cell as a model material. The performance of these cells compared well with unmodified coin cells, while providing information about structural changes in the active material as the cell is repeatedly charged and discharged.

  14. In situ X-ray powder diffraction studies of the synthesis of graphene oxide and formation of reduced graphene oxide

    NASA Astrophysics Data System (ADS)

    Storm, Mie Møller; Johnsen, Rune E.; Norby, Poul

    2016-08-01

    Graphene oxide (GO) and reduced graphene oxide (rGO) are important materials in a wide range of fields. The modified Hummers methods, for synthesizing GO, and subsequent thermal reduction to rGO, are often employed for production of rGO. However, the mechanism behinds these syntheses methods are still unclear. We present an in situ X-ray diffraction study of the synthesis of GO and thermal reduction of GO. The X-ray diffraction revealed that the Hummers method includes an intercalation state and finally formation of additional crystalline material. The formation of GO is observed during both the intercalation and the crystallization stage. During thermal reduction of GO three stages were observed: GO, a disordered stage, and the rGO stage. The appearance of these stages depends on the heating ramp. The aim of this study is to provide deeper insight into the chemical and physical processes during the syntheses.

  15. An ultra-high vacuum electrochemical flow cell for in situ/operando soft X-ray spectroscopy study.

    PubMed

    Bora, Debajeet K; Glans, Per-Anders; Pepper, John; Liu, Yi-Sheng; Du, Chun; Wang, Dunwei; Guo, J-H

    2014-04-01

    An in situ flow electrochemical cell has been designed and fabricated to allow better seal under UHV chamber thus to achieve a good signal to noise ratio in fluorescence yield detection of X-ray absorption spectra for spectroelectrochemical study. The cell also stabilizes the thin silicon nitride membrane window in an effective manner so that the liquid cell remains intact during X-ray absorption experiments. With the improved design of the liquid cell, electrochemical experiments such as cyclic voltammetry have been performed for 10 cycles with a good stability of sample window. Also an operando electrochemical experiment during photoelectrochemistry has been performed on n-type hematite electrode deposited on silicon nitride window. The experiment allows us to observe the formation of two extra electronic transitions before pre edge of O K-edge spectra. PMID:24784592

  16. An ultra-high vacuum electrochemical flow cell for in situ/operando soft X-ray spectroscopy study

    NASA Astrophysics Data System (ADS)

    Bora, Debajeet K.; Glans, Per-Anders; Pepper, John; Liu, Yi-Sheng; Du, Chun; Wang, Dunwei; Guo, J.-H.

    2014-04-01

    An in situ flow electrochemical cell has been designed and fabricated to allow better seal under UHV chamber thus to achieve a good signal to noise ratio in fluorescence yield detection of X-ray absorption spectra for spectroelectrochemical study. The cell also stabilizes the thin silicon nitride membrane window in an effective manner so that the liquid cell remains intact during X-ray absorption experiments. With the improved design of the liquid cell, electrochemical experiments such as cyclic voltammetry have been performed for 10 cycles with a good stability of sample window. Also an operando electrochemical experiment during photoelectrochemistry has been performed on n-type hematite electrode deposited on silicon nitride window. The experiment allows us to observe the formation of two extra electronic transitions before pre edge of O K-edge spectra.

  17. Ionic Liquids as a Reference Material Candidate for the Quick Performance Check of Energy Dispersive X-ray Spectrometers for the Low Energy Range below 1 keV

    PubMed Central

    2016-01-01

    Ionic liquids (ILs) are proposed as simple and efficient test materials to evaluate the performance of energy dispersive X-ray spectrometers (EDS) in the low energy range below 1 keV. By only one measurement, C Kα, N Kα, O Kα, and F Kα X-ray lines can be excited. Additionally, the S Kα line at 2.3 keV and, particularly, the S L series at 149 eV complete the picture with X-ray lines offered by the selected ILs. The well-known (certifiable) elemental composition of the ILs selected in the present study can be used to check the accuracy of results produced with the available EDS quantification routines in the low energy range, simultaneously, for several low atomic number elements. A comparison with other reference materials in use for testing the performance of EDS in the low energy range is included. PMID:27336962

  18. Method for the determination of Pd-catalyst residues in active pharmaceutical ingredients by means of high-energy polarized-beam energy dispersive X-ray fluorescence.

    PubMed

    Marguí, E; Van Meel, K; Van Grieken, R; Buendía, A; Fontàs, C; Hidalgo, M; Queralt, I

    2009-02-15

    In medicinal chemistry, Pd is perhaps the most-widely utilized precious metal, as catalyst in reactions which represent key transformations toward the synthesis of new active pharmaceutical ingredients (APIs). The disadvantage of this metal-catalyzed chemistry is that expensive and toxic metal residues are invariably left bound to the desired product. Thus, stringent regulatory guidelines exist for the amount of residual Pd that a drug candidate is allowed to contain. In this work, a rapid and simple method for the determination of Pd in API samples by high-energy polarized-beam energy dispersive X-ray fluorescence spectrometry has been developed and validated according to the specification limits of current legislation (10 mg kg(-1) Pd) and the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH guidelines). Sample and calibration standards preparation includes a first step of homogenization and then, in a second step, the pressing of the powdered material into pellets without any chemical treatment. The use of several synthetic calibration standards made of cellulose to simulate the API matrix appears to be an effective means to obtain reliable calibration curves with a good spread of data points over the working range. With the use of the best measuring conditions, the limit of detection (0.11 mg kg(-1) Pd) as well as the limit of quantitation (0.37 mg kg(-1) Pd) achieved meet rigorous requirements. The repeatability of the XRF measurement appeared to be less than 2%, while the precision of the whole method was around 7%. Trueness was evaluated by analyzing spiked API samples at the level of the specification limit and calculating the recovery factor, which was better than 95%. To study the applicability of the developed methodology for the intended purpose, three batches of the studied API were analyzed for their Pd content, and the attained results were comparable to those obtained by the

  19. Assessment of the effects of laser photobiomodulation on peri-implant bone repair through energy dispersive x-ray fluorescence: A study of dogs

    NASA Astrophysics Data System (ADS)

    Menezes, R. F.; Araújo, N. C.; Carneiro, V. S. M.; Moreno, L. M.; Guerra, L. A. P.; Santos Neto, A. P.; Gerbi, M. E. M.

    2016-03-01

    Bone neoformation is essential in the osteointegration of implants and has been correlated with the repair capacity of tissues, the blood supply and the function of the cells involved. Laser therapy accelerates the mechanical imbrication of peri-implant tissue by increasing osteoblastic activity and inducing ATP, osteopontin and the expression of sialoproteins. Objective: The aim of the present study was to assess peri-implant bone repair using the tibia of dogs that received dental implants and laser irradiation (AsGaAl 830nm - 40mW, CW, f~0.3mm) through Energy Dispersive X-ray Fluorescence (EDXRF). Methodology: Two groups were established: G1 (Control, n=20; two dental implants were made in the tibia of each animal; 10 animals); G2 (Experimental, n=20, two dental implants were made in the tibia each animal + Laser therapy; 10 animals). G2 was irradiated every 48 hours for two weeks, with a total of seven sessions. The first irradiation was conducted during the surgery, at which time a point in the surgical alveolus was irradiated prior to the placement of the implant and four new spatial positions were created to the North, South, East and West (NSEW) of the implant. The subsequent sessions involved irradiation at these four points and at one infra-implant point (in the direction of the implant apex). Each point received 4J/cm2 and a total dose of 20J/cm2 per session (treatment dose=140J/cm2). The specimens were removed 15 and 30 days after the operation for the EDXRF test. The Mann- Whitney statistical test was used to assess the results. Results: The increase in the calcium concentration in the periimplant region of the irradiated specimens (G2) was statistically significant (p < 0.05), when compared with the control group (G1). Conclusion: The results of the present study show that irradiation with the AsGaAl laser promoted an acceleration in bone repair in the peri-implant region.

  20. Chemical Analysis of Reaction Rims on Olivine Crystals in Natural Samples of Black Dacite Using Energy-Dispersive X-Ray Spectroscopy, Lassen Peak, CA.

    NASA Astrophysics Data System (ADS)

    Graham, N. A.

    2014-12-01

    Lassen Volcanic Center is the southernmost volcanic region in the Cascade volcanic arc formed by the Cascadia Subduction Zone. Lassen Peak last erupted in 1915 in an arc related event producing a black dacite material containing xenocrystic olivine grains with apparent orthopyroxene reaction rims. The reaction rims on these olivine grains are believed to have formed by reactions that ensued from a mixing/mingling event that occurred prior to eruption between the admixed mafic andesitic magma and a silicic dacite host material. Natural samples of the 1915 black dacite from Lassen Peak, CA were prepared into 15 polished thin sections and carbon coated for analysis using a FEI Quanta 250 Scanning Electron Microscope (SEM) to identify and measure mineral textures and disequilibrium reaction rims. Observed mineralogical textures related to magma mixing include biotite and amphibole grains with apparent dehydration/breakdown rims, pyroxene-rimmed quartz grains, high concentration of microlites in glass matrix, and pyroxene/amphibole reaction rims on olivine grains. Olivine dissolution is evidenced as increased iron concentration toward convolute edges of olivine grains as observed by Backscatter Electron (BSE) imagery and elemental mapping using NSS spectral imaging software. In an attempt to quantify the area of reaction rim growth on olivine grains within these samples, high-resolution BSE images of 30 different olivine grains were collected along with Energy-Dispersive X-Ray Spectroscopy (EDS) of different phases. Olivine cores and rims were extracted from BSE images using Photoshop and saved as separate image files. ImageJ software was used to calculate the area (μm2) of the core and rim of these grains. Average pyroxene reaction rim width for 30 grains was determined to be 11.68+/-1.65 μm. Rim widths of all 30 grains were averaged together to produce an overall average rim width for the Lassen Peak black dacite. By quantifying the reaction rims on olivine grains

  1. In-situ x-ray monitoring of damage accumulation in SiC/RBSN tensile specimens

    NASA Technical Reports Server (NTRS)

    Baaklini, George Y.; Bhatt, Ramakrishna T.

    1991-01-01

    The room-temperature tensile testing of silicon carbide fiber reinforced reaction-bonded silicon nitride (SiC/RBSN) composite specimens was monitored by using in-situ x ray film radiography. Radiographic evaluation before, during, and after loading provided data on the effect of preexisting volume flaws (high density impurities, and local density variations) on the fracture behavior of composites. Results from (0)1, (0)3, (0)5, and (0)8 composite specimens, showed that x ray film radiography can monitor damage accumulations during tensile loading. Matrix cracking, fiber-matrix debonding, and fiber pullout were imaged throughout the tensile loading history of the specimens. Further, in-situ film radiography was found to be a helpful and practical technique for estimating interfacial shear strength between the SiC fiber and the RBSN matrix by the matrix crack spacing method. It is concluded that pretest, in-situ, and post-test radiography can provide for a greater understanding of ceramic matrix composite mechanical behavior, a verification of related experimental procedures, and a validation and development of related analytical models.

  2. Energy-Dispersive X-ray Diffraction Investigation of Amorphous Lithium Borate Structure: A Demonstration of the Paris-Edinburgh Cell Setup at 16BM-B at the APS

    NASA Astrophysics Data System (ADS)

    Yu, T.; Wang, Y.; Park, C.; Stebbins, J. F.; Sakamaki, T.; Shen, G.

    2010-12-01

    Knowledge of the structure and physical properties of silicate melts at a fundamental level is essential to help us understand the dynamics of mineral crystallization and fractionation, magma activities, thermal transport, etc. inside the Earth. The boron coordination number change due to pressure might be analogous to what happens on silicates at high pressure. Therefore, to understand the structure behavior under extreme pressure and temperature conditions in disordered silicates, borates are good cases to start with. And eventually we hope to apply the experimental method to silicates that are important in Earth Science. Results from previous NMR, Raman, and neutron diffraction studies on borate glasses show that boron has mixed coordination numbers that vary strongly with composition and temperature [Cormier et al., 2006]. Inelastic x-ray scattering of borate glass structure under pressure has been studied by Lee et al. [Lee et al., 2007]. However, studies of the pressure effect on liquid alkali borate structure are limited. In situ high pressure and high temperature x-ray total scattering of liquid state alkali borate has not even been reported. A 230-ton Paris-Edinburgh (PE) Press has been installed at Beamline 16BM-B at the Advanced Photon Source, Argonne National Laboratory since June 2010. The PE Cell is capable of generating high pressure up to ~10GPa and can heat the sample cell up to 2100K in temperature. The bending magnet white beam spanning a large energy range up to 120 KeV provides sufficient energy to reach our experimental needs. The germanium solid state detector is mounted on a Huber rotation stage, which allows us to collect diffraction signal at two theta angles as high as 39.5 degrees. This, combined with the broad white beam spectrum, will provide a large Q range up to about 40 inverse Angstroms, making this setup an ideal beamline for studying non-crystalline materials. We have successfully collected high pressure (up to 7GPa) and high

  3. An X-Ray Microprobe for In-Situ Stone and Wood Characterization

    NASA Astrophysics Data System (ADS)

    Lovoi, P.; Asmus, J. F.

    NonDestructive Testing (NDT) has become an essential ingredient in the conservation of artworks and in the preservation of historic buildings. In many instances it is necessary to characterize the underlying strata of an artistic or historic object in order to plan technical conservation measures, to understand its history, to authenticate it, or to search for hidden features. X-ray and gamma-ray radiography as well as infrared imaging have been ubiquitous in conservation practice for generations. Recent decades have also seen the introduction of ultrasonic imaging, thermovision, x-ray fluorescence, neutron activation analyses, holographic interferometry, isotopic and trace element analyses, the electron microprobe, the laser microprobe, microwave impulse radar, eddy current imaging, and fiber-optic imaging. Unfortunately, for mainstream conservation and preservation some of these technologies are too costly or difficult to be implemented in any general way. In other instances penetration is too superficial or signals from the depth of interest are masked by interferences. Nevertheless, sufficiently important problems have arisen to warrant the utilization of each of the above NDT technologies as well as still others. A new diagnostic device has been introduced into the conservation field. Stone characterization analyses are reported using miniature x-ray devices that can be inserted into cracks and holes in specimens of interest. The family of x-ray tubes employed in these studies range in diameter from 1 to 6 mm. Operating voltages up to 50 kV are available. Electrical power and cooling are delivered through a flexible cable that has a bend diameter of less than 3 cm. Thus, it was possible to insert the x-ray tube into small holes and cracks in marble stones. In this manner radiographs of the outer strata of stones (and embedded metal pins) have been produced without having to transmit through the entire thickness of large blocks. It should also be possible to

  4. In situ X-ray ptychography imaging of high-temperature CO{sub 2} acceptor particle agglomerates

    SciTech Connect

    Høydalsvik, Kristin; Bø Fløystad, Jostein; Esmaeili, Morteza; Mathiesen, Ragnvald H.; Breiby, Dag W.; Zhao, Tiejun; Rønning, Magnus; Diaz, Ana; Andreasen, Jens W.

    2014-06-16

    Imaging nanoparticles under relevant reaction conditions of high temperature and gas pressure is difficult because conventional imaging techniques, like transmission electron microscopy, cannot be used. Here we demonstrate that the coherent diffractive imaging technique of X-ray ptychography can be used for in situ phase contrast imaging in structure studies at atmospheric pressure and elevated temperatures. Lithium zirconate, a candidate CO{sub 2} capture material, was studied at a pressure of one atmosphere in air and in CO{sub 2}, at temperatures exceeding 600 °C. Images with a spatial resolution better than 200 nm were retrieved, and possibilities for improving the experiment are described.

  5. A flow cell for in situ synchrotron x-ray diffraction studies of scale formation under Bayer processing conditions.

    PubMed

    Webster, Nathan A S; Madsen, Ian C; Loan, Melissa J; Scarlett, Nicola V Y; Wallwork, Kia S

    2009-08-01

    The design, construction, and commissioning of a stainless steel flow cell for in situ synchrotron x-ray diffraction studies of scale formation under Bayer processing conditions is described. The use of the cell is demonstrated by a study of Al(OH)(3) scale formation on a mild steel substrate from synthetic Bayer liquor at 70 degrees C. The cell design allows for interchangeable parts and substrates and would be suitable for the study of scale formation in other industrial processes. PMID:19725670

  6. In-situ Synchrotron X-ray Microdiffraction Study of Lattice Rotation in Polycrystalline Materials during Uniaxial Deformations

    SciTech Connect

    Joo, H.D.; Bark, C.W.; Koo, Y.M.; Kim, K.H.; Tamura, N.

    2004-05-12

    Recent experiments have shown that formation of dislocation cell structures and rotation of structural elements at the macroscopic level are fundamental to the development of plastic deformation. However, attention should also be focused on micro-volumes because local stress and strain can significantly differ from their averaged values at the macroscale. In-situ orientation measurements in copper polycrystals during uniaxial deformation were performed using synchrotron x-ray microdiffraction at the Advanced Light Source. We observed heterogeneities in deformation-induced microstructure within individual grains. Different slip systems in particular can be simultaneously activated among neighboring volume elements of individual grains.

  7. In-situ synchrotron X-ray microdiffraction study of lattice rotation in polycrystalline materials during uniaxial deformations

    SciTech Connect

    Joo, H.D.; Kim, K.H.; Bark, C.W.; Koo, Y.M.; Tamura, N.

    2004-07-19

    Recent experiments have shown that formation of dislocation cell structures and rotation of structural elements at the macroscopic level are fundamental to the development of plastic deformation. However, attention should also be focused on micro-volumes because local stress and strain can significantly differ from their averaged values at the macroscale. In-situ orientation measurements in copper polycrystals during uniaxial deformation were performed using synchrotron x-ray microdiffraction at the Advanced Light Source. We observed heterogeneities in deformation-induced microstructure within individual grains. Different slip systems in particular can be simultaneously activated among neighboring volume elements of individual grains.

  8. Estimation of bearing contact angle in-situ by X-ray kinematography

    NASA Technical Reports Server (NTRS)

    Fowler, P. H.; Manders, F.

    1982-01-01

    The mounted, preloaded contact angle of the structural bearings in the assembled design mechanical assembly was measured. A modification of the Turns method is presented, based upon the clarity and definition of moving parts achieved with X-ray technique and cinematic display. Contact angle is estimated by counting the number of bearings passing a given point as a function of number of turns of the shaft. Ball and pitch diameter variations are discussed. Ball train and shaft angle uncertainties are also discussed.

  9. In Situ X-Ray Absorption Spectroscopy Study of the LiNiO2 Electrode

    NASA Astrophysics Data System (ADS)

    Mansour, A. N.; McBreen, J.; Melendres, C. A.

    1997-03-01

    LiNiO2 is one of the most promising active material for the development of novel 4V rechargeable lithium batteries. Recent x-ray diffraction studies showed that the electrochemical reactivity of this electrode is sensitive to the structure of the starting material as well as the charged products. To further examine this material, we have conducted an x-ray absorption spectroscopy (XAS) study to determine the structure of this electrode as a function of its charge state. Specifically, the x-ray absorption Ni K-edge energy, the pre-edge structure, and local structure parameters such as bond lengths, coordination numbers and disorders were investigated at various states of charge corresponding to Li_(1-x)NiO2 for x values of 0.0, 0.11, 0.23, 0.34, 0.45, 0.82, and 0.99. The charging which proceeds via lithium de-intercalation was conducted using constant current anodization at 0.5 mA in a non aqueous electrolyte consisting of 1M LiPF6 in 1:1:3 propylene ! carbonate, ethylene carbonate and dimethyl carbonate. The XAS results for this electrode will be compared with those of γ-NiOOH and KNiIO_6, the latter being used as a reference for quadrivalent nickel.

  10. Quick scanning monochromator for millisecond in situ and in operando X-ray absorption spectroscopy.

    PubMed

    Müller, O; Lützenkirchen-Hecht, D; Frahm, R

    2015-09-01

    The design and capabilities of a novel Quick scanning Extended X-ray Absorption Fine Structure (QEXAFS) monochromator are presented. The oscillatory movement of the crystal stage is realized by means of a unique open-loop driving scheme operating a direct drive torque motor. The entire drive mechanics are installed inside of a goniometer located on the atmospheric side of the vacuum chamber. This design allows remote adjustment of the oscillation frequency and spectral range, giving complete control of QEXAFS measurements. It also features a real step-scanning mode, which operates without a control loop to prevent induced vibrations. Equipped with Si(111) and Si(311) crystals on a single stage, it facilitates an energy range from 4.0 keV to 43 keV. Extended X-ray absorption fine structure spectra up to k = 14.4 Å(-1) have been acquired within 17 ms and X-ray absorption near edge structure spectra covering more than 200 eV within 10 ms. The achieved data quality is excellent as shown by the presented measurements. PMID:26429455

  11. Quick scanning monochromator for millisecond in situ and in operando X-ray absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    Müller, O.; Lützenkirchen-Hecht, D.; Frahm, R.

    2015-09-01

    The design and capabilities of a novel Quick scanning Extended X-ray Absorption Fine Structure (QEXAFS) monochromator are presented. The oscillatory movement of the crystal stage is realized by means of a unique open-loop driving scheme operating a direct drive torque motor. The entire drive mechanics are installed inside of a goniometer located on the atmospheric side of the vacuum chamber. This design allows remote adjustment of the oscillation frequency and spectral range, giving complete control of QEXAFS measurements. It also features a real step-scanning mode, which operates without a control loop to prevent induced vibrations. Equipped with Si(111) and Si(311) crystals on a single stage, it facilitates an energy range from 4.0 keV to 43 keV. Extended X-ray absorption fine structure spectra up to k = 14.4 Å-1 have been acquired within 17 ms and X-ray absorption near edge structure spectra covering more than 200 eV within 10 ms. The achieved data quality is excellent as shown by the presented measurements.

  12. In situ microfluidic dialysis for biological small-angle X-ray scattering

    PubMed Central

    Skou, Magda; Skou, Søren; Jensen, Thomas G.; Vestergaard, Bente; Gillilan, Richard E.

    2014-01-01

    Owing to the demand for low sample consumption and automated sample changing capabilities at synchrotron small-angle X-ray (solution) scattering (SAXS) beamlines, X-ray microfluidics is receiving continuously increasing attention. Here, a remote-controlled microfluidic device is presented for simultaneous SAXS and ultraviolet absorption measurements during protein dialysis, integrated directly on a SAXS beamline. Microfluidic dialysis can be used for monitoring structural changes in response to buffer exchange or, as demonstrated, protein concentration. By collecting X-ray data during the concentration procedure, the risk of inducing protein aggregation due to excessive concentration and storage is eliminated, resulting in reduced sample consumption and improved data quality. The proof of concept demonstrates the effect of halted or continuous flow in the microfluidic device. No sample aggregation was induced by the concentration process at the levels achieved in these experiments. Simulations of fluid dynamics and transport properties within the device strongly suggest that aggregates, and possibly even higher-order oligomers, are preferentially retained by the device, resulting in incidental sample purification. Hence, this versatile microfluidic device enables investigation of experimentally induced structural changes under dynamically controllable sample conditions. PMID:25242913

  13. Observing the in situ chiral modification of Ni nanoparticles using scanning transmission X-ray microspectroscopy

    NASA Astrophysics Data System (ADS)

    Watson, David J.; Acharya, Sushma; Nicklin, Richard E. J.; Held, Georg

    2014-11-01

    Enantioselective heterogeneous hydrogenation of Cdbnd O bonds is of great potential importance in the synthesis of chirally pure products for the pharmaceutical and fine chemical industries. One of the most widely studied examples of such a reaction is the hydrogenation of β-ketoesters and β-diketoesters over Ni-based catalysts in the presence of a chiral modifier. Here we use scanning transmission X-ray microscopy combined with near-edge X-ray absorption fine structure spectroscopy (STXM/NEXAFS) to investigate the adsorption of the chiral modifier, namely (R,R)-tartaric acid, onto individual nickel nanoparticles. The C K-edge spectra strongly suggest that tartaric acid deposited onto the nanoparticle surfaces from aqueous solutions undergoes a keto-enol tautomerisation. Furthermore, we are able to interrogate the Ni L2,3-edge resonances of individual metal nanoparticles which, combined with X-ray diffraction (XRD) patterns showed them to consist of a pure nickel phase rather than the more thermodynamically stable bulk nickel oxide. Importantly, there appears to be no "particle size effect" on the adsorption mode of the tartaric acid in the particle size range ~ 90-~ 300 nm.

  14. In-situ x-ray microscopy of phase and composition distributions in metal alloys during solidification

    NASA Astrophysics Data System (ADS)

    Kaukler, William F.; Curreri, Peter A.

    1999-07-01

    This research applies a state of the art x-ray transmission microscope, to image the solidification of metallic or semiconductor alloys in real-time. By employing a hard x-ray source with sub-micron dimensions, resolutions of up to 2 micrometers can be obtained with magnifications of over 800 X. Specimen growth conditions were optimized and the best imaging technologies applied to maintain x-ray image resolution, contrast and sensitivity. In addition, a special furnace design is required to permit controlled growth conditions and still offer maximum resolution and image contrast. We have successfully imaged in real-time: interfacial morphologies, phase growth, coalescence, incorporation of phases into the growing interface, and the solute boundary layer in the liquid at the solid-liquid interface. We have also measured true local growth rates and can evaluate segregation structures in the solid; a form of in situ metallography. Composition gradients within the specimen cause variations in absorption of the flux such that the final image represents a spatial integration of composition. During this study, the growth of secondary phase fibers and lamellae form eutectic and monotectic alloys have been imaged during solidification, in real-time, for the first time in bulk metal alloys.

  15. In-situ X-ray diffraction snapshotting: Determination of the kinetics of a photodimerization within a single crystal

    PubMed Central

    Hu, Fei-Long; Wang, Shu-Long; Lang, Jian-Ping; Abrahams, Brendan F.

    2014-01-01

    In a single-crystal-to-single-crystal (SCSC) transformation, a preformed three-dimensional coordination polymer,[Ni3(oba)2(bpe)2(SO4)(H2O)4]·H2O (H2oba = 4,4′-oxydibenzoic acid; bpe = (E)-1,2-di(pyridin-4-yl)ethane) (1), was shown to undergo a [2+2] cycloaddition reaction upon exposure to UV irradiation. The kinetics of this reaction were followed by taking “snapshots” of the solid state transformation using in situ single crystal X-ray crystallography; a first order process was indicated. The reaction rate was influenced by many factors such as the separation of the sample from the UV light source, the heat produced by the UV irradiation, the light flux of the UV lamp used, the size of the single-crystal and the powder samples. The investigation of the kinetics was complemented by 1H NMR studies. The results clearly demonstrate that in situ single-crystal X-ray diffraction is able to provide useful insights into the gradual formation of the photoproducts and the reaction processes. The work also offers a clear indication that it is possible to use the technique to study the kinetics of other photocycloaddition reactions and SCSC processes in general. PMID:25351677

  16. In situ high-temperature X-ray diffraction characterization of yttrium-implanted extra low-carbon steel

    SciTech Connect

    Caudron, E.; Buscail, H.; Perrier, S.

    1999-11-01

    Yttrium-implanted and unimplanted extra low-carbon steel samples were analyzed at T = 700 C and under an oxygen partial pressure P{sub O2} = 0.041Pa for 24 h to show the yttrium implantation effect on extra low-carbon steel high-temperature corrosion resistance. Sample oxidation weight gains were studied by thermogravimetry, and structural analyses were performed using in situ high-temperature X-ray diffraction with the same experimental conditions. The aim of this paper is to show the initial nucleation stage of the main compounds induced by oxidation at high temperatures according to the initial sample treatment (yttrium-implanted or unimplanted). The results obtained by in situ high-temperature X-ray diffraction will be compared to those by thermogravimetry to show the existing correlation between weight gain curves and structural studies. Results allow one to understand the improved corrosion resistance of yttrium-implanted extra low-carbon steel at high temperatures.

  17. In-situ transmission x-ray microscopy study of photon-induced oxidation of silver nanowires

    NASA Astrophysics Data System (ADS)

    Yu, Le; Sun, Yugang; Wang, Yuxin; Cai, Zhonghou; Han, Ping; Cheng, X. M.

    Oxidation of metal nanoparticles usually follows a Kirkendall process to transform solid nanoparticles to hollow metal oxide nanoshells. However the morphological trajectory of nanoparticles and the mass diffusion kinetics involved in the nanoscale Kirkendall process are complex. In this presentation we report the use of in-situ transmission x-ray microscopy (TXM) to directly image individual silver nanowires under oxidation atmosphere, which are created from radiolysis of air under illumination of the focused synchrotron x-ray beam. The in-situ results clearly show the morphological transformation from solid silver nanowires to hollow nanotubes in the course of oxidation reaction of silver. Quantitative analysis of the time-resolved TXM images provides unprecedented details on reaction kinetics and mass diffusion kinetics associated with the oxidation process. Work at Bryn Mawr College is supported by NSF Grant #1207085. Use of the Advanced Photon Source and the Center for Nanoscale Materials at Argonne National Laboratory was supported by the U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.

  18. Predicting In-Situ X-ray Diffraction for the SrTiO3/Liquid Interface from First Principles

    NASA Astrophysics Data System (ADS)

    Letchworth-Weaver, Kendra; Gunceler, Deniz; Sundararaman, Ravishankar; Huang, Xin; Brock, Joel; Arias, T. A.

    2013-03-01

    Recent advances in experimental techniques, such as in-situ x-ray diffraction, allow researchers to probe the solid-liquid interface in electrochemical systems under operating conditions. These advances offer an unprecedented opportunity for theory to predict properties of electrode materials in aqueous environments and inform the design of energy conversion and storage devices. To compare with experiment, these theoretical studies require microscopic details of both the liquid and the electrode surface. Joint Density Functional Theory (JDFT), a computationally efficient alternative to molecular dynamics, couples a classical density-functional, which captures molecular structure of the liquid, to a quantum-mechanical functional for the electrode surface. We present a JDFT exploration of SrTiO3, which can catalyze solar-driven water splitting, in an electrochemical environment. We determine the geometry of the polar SrTiO3 surface and the equilibrium structure of the contacting liquid, as well as the influence of the liquid upon the electronic structure of the surface. We then predict the effect of the fluid environment on x-ray diffraction patterns and compare our predictions to in-situ measurements performed at the Cornell High Energy Synchrotron Source (CHESS). This material is based upon work supported by the Energy Materials Center at Cornell (EMC2), an Energy Frontier Research Center funded by the U.S. Department of Energy.

  19. In-situ X-ray diffraction snapshotting: Determination of the kinetics of a photodimerization within a single crystal

    NASA Astrophysics Data System (ADS)

    Hu, Fei-Long; Wang, Shu-Long; Lang, Jian-Ping; Abrahams, Brendan F.

    2014-10-01

    In a single-crystal-to-single-crystal (SCSC) transformation, a preformed three-dimensional coordination polymer,[Ni3(oba)2(bpe)2(SO4)(H2O)4].H2O (H2oba = 4,4'-oxydibenzoic acid; bpe = (E)-1,2-di(pyridin-4-yl)ethane) (1), was shown to undergo a [2+2] cycloaddition reaction upon exposure to UV irradiation. The kinetics of this reaction were followed by taking ``snapshots'' of the solid state transformation using in situ single crystal X-ray crystallography; a first order process was indicated. The reaction rate was influenced by many factors such as the separation of the sample from the UV light source, the heat produced by the UV irradiation, the light flux of the UV lamp used, the size of the single-crystal and the powder samples. The investigation of the kinetics was complemented by 1H NMR studies. The results clearly demonstrate that in situ single-crystal X-ray diffraction is able to provide useful insights into the gradual formation of the photoproducts and the reaction processes. The work also offers a clear indication that it is possible to use the technique to study the kinetics of other photocycloaddition reactions and SCSC processes in general.

  20. Fast in situ phase and stress analysis during laser surface treatment: a synchrotron x-ray diffraction approach.

    PubMed

    Kostov, V; Gibmeier, J; Wilde, F; Staron, P; Rössler, R; Wanner, A

    2012-11-01

    An in situ stress analysis by means of synchrotron x-ray diffraction was carried out during laser surface hardening of steel. A single exposure set-up that based on a special arrangement of two fast silicon strip line detectors was established, allowing for fast stress analysis according to the sin(2)ψ x-ray analysis method. For the in situ experiments a process chamber was designed and manufactured, which is described in detail. First measurements were carried out at the HZG undulator imaging beamline (IBL, beamline P05) at the synchrotron storage ring PETRA III, DESY, Hamburg (Germany). The laser processing was carried out using a 6 kW high power diode laser system. Two different laser optics were compared, a Gaussian optic with a focus spot of ø 3 mm and a homogenizing optic with a rectangular spot dimension of 8 × 8 mm(2). The laser processing was carried out using spot hardening at a heating-/cooling rate of 1000 K/s and was controlled via pyrometric temperature measurement using a control temperature of 1150 °C. The set-up being established during the measuring campaign allowed for this first realization data collection rates of 10Hz. The data evaluation procedure applied enables the separation of thermal from elastic strains and gains unprecedented insight into the laser hardening process. PMID:23206092

  1. Low-dose phase-based X-ray imaging techniques for in situ soft tissue engineering assessments.

    PubMed

    Izadifar, Zohreh; Honaramooz, Ali; Wiebe, Sheldon; Belev, George; Chen, Xiongbiao; Chapman, Dean

    2016-03-01

    In tissue engineering, non-invasive imaging of biomaterial scaffolds and tissues in living systems is essential to longitudinal animal studies for assessments without interrupting the repair process. Conventional X-ray imaging is inadequate for use in soft tissue engineering due to the limited absorption difference between the soft tissue and biomaterial scaffolds. X-ray phase-based imaging techniques that derive contrast from refraction or phase effects rather than absorption can provide the necessary contrast to see low-density biomaterial scaffolds and tissues in large living systems. This paper explores and compares three synchrotron phase-based X-ray imaging techniques-computed tomography (CT)-diffraction enhanced imaging (DEI), -analyzer based imaging (ABI), and -phase contrast imaging (PCI)-for visualization and characterization of low-density biomaterial scaffolds and tissues in situ for non-invasive soft tissue engineering assessments. Intact pig joints implanted with polycaprolactone scaffolds were used as the model to assess and compare the imaging techniques in terms of different qualitative and quantitative criteria. For long-term in vivo live animal imaging, different strategies for reducing the imaging radiation dose and scan time-reduced number of CT projections, region of interest, and low resolution imaging-were examined with the presented phase-based imaging techniques. The results demonstrated promising capabilities of the phase-based techniques for visualization of biomaterial scaffolds and soft tissues in situ. The low-dose imaging strategies were illustrated effective for reducing the radiation dose to levels appropriate for live animal imaging. The comparison among the imaging techniques suggested that CT-DEI has the highest efficiency in retaining image contrast at considerably low radiation doses. PMID:26761779

  2. Phase transitions in freeze-dried systems - quantification using in situ synchrotron X-ray diffractometry

    SciTech Connect

    Varshney, Dushyant B.; Sundaramurthi, Prakash; Kumar, Satyendra; Shalaev, Evgenyi Y.; Kang, Shin-Woong; Gatlin, Larry A.; Suryanarayanan, Raj

    2009-09-02

    The purpose is: (1) To develop a synchrotron X-ray diffraction (SXRD) method to monitor phase transitions during the entire freeze-drying cycle. Aqueous sodium phosphate buffered glycine solutions with initial glycine to buffer molar ratios of 1:3 (17:50 mM), 1:1 (50 mM) and 3:1 were utilized as model systems. (2) To investigate the effect of initial solute concentration on the crystallization of glycine and phosphate buffer salt during lyophilization. Phosphate buffered glycine solutions were placed in a custom-designed sample cell for freeze-drying. The sample cell, covered with a stainless steel dome with a beryllium window, was placed on a stage capable of controlled cooling and vacuum drying. The samples were cooled to -50 C and annealed at -20 C. They underwent primary drying at -25 C under vacuum until ice sublimation was complete and secondary drying from 0 to 25 C. At different stages of the freeze-drying cycle, the samples were periodically exposed to synchrotron X-ray radiation. An image plate detector was used to obtain time-resolved two-dimensional SXRD patterns. The ice, {beta}-glycine and DHPD phases were identified based on their unique X-ray peaks. When the solutions were cooled and annealed, ice formation was followed by crystallization of disodium hydrogen phosphate dodecahydrate (DHPD). In the primary drying stage, a significant increase in DHPD crystallization followed by incomplete dehydration to amorphous disodium hydrogen phosphate was evident. Complete dehydration of DHPD occurred during secondary drying. Glycine crystallization was inhibited throughout freeze-drying when the initial buffer concentration (1:3 glycine to buffer) was higher than that of glycine. A high-intensity X-ray diffraction method was developed to monitor the phase transitions during the entire freeze-drying cycle. The high sensitivity of SXRD allowed us to monitor all the crystalline phases simultaneously. While DHPD crystallizes in frozen solution, it dehydrates

  3. Characterization of toners and inkjets by laser ablation spectrochemical methods and Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy

    NASA Astrophysics Data System (ADS)

    Trejos, Tatiana; Corzo, Ruthmara; Subedi, Kiran; Almirall, José

    2014-02-01

    Detection and sourcing of counterfeit currency, examination of counterfeit security documents and determination of authenticity of medical records are examples of common forensic document investigations. In these cases, the physical and chemical composition of the ink entries can provide important information for the assessment of the authenticity of the document or for making inferences about common source. Previous results reported by our group have demonstrated that elemental analysis, using either Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) or Laser Ablation Induced Breakdown Spectroscopy (LIBS), provides an effective, practical and robust technique for the discrimination of document substrates and writing inks with minimal damage to the document. In this study, laser-based methods and Scanning Electron Microscopy-Energy Dispersive X-Ray Spectroscopy (SEM-EDS) methods were developed, optimized and validated for the forensic analysis of more complex inks such as toners and inkjets, to determine if their elemental composition can differentiate documents printed from different sources and to associate documents that originated from the same printing source. Comparison of the performance of each of these methods is presented, including the analytical figures of merit, discrimination capability and error rates. Different calibration strategies resulting in semi-quantitative and qualitative analysis, comparison methods (match criteria) and data analysis and interpretation tools were also developed. A total of 27 black laser toners originating from different manufacturing sources and/or batches were examined to evaluate the discrimination capability of each method. The results suggest that SEM-EDS offers relatively poor discrimination capability for this set (~ 70.7% discrimination of all the possible comparison pairs or a 29.3% type II error rate). Nonetheless, SEM-EDS can still be used as a complementary method of analysis since it has

  4. X-ray chemical analyzer for field applications

    DOEpatents

    Gamba, Otto O. M.

    1977-01-01

    A self-supporting portable field multichannel X-ray chemical analyzer system comprising a lightweight, flexibly connected, remotely locatable, radioisotope-excited sensing probe utilizing a cryogenically-cooled solid state semi-conductor crystal detector for fast in situ non-destructive, qualitative and quantitative analysis of elements in solid, powder, liquid or slurried form, utilizing an X-ray energy dispersive spectrometry technique.

  5. [Energy dispersive x-ray fluorescence spectrometry--a forensic chemistry method for detection of bullet metal residue in gunshot wounds].

    PubMed

    Havel, J; Zelenka, K

    2003-04-01

    The article describes using of energo-dispersive X-ray fluorescence spectrometry (EDXRF) as the forensic method as the tool for detection of metals (gunshot residues--GSR) in connection with gunshot-wounds of persons. PMID:12874887

  6. In Situ identification of mineral resources with an X-ray-optical "Hand-Lens" instrument

    NASA Technical Reports Server (NTRS)

    Marshall, J.; Koppel, L.; Bratton, C.; Metzger, E.; Hecht, M.

    1997-01-01

    The recognition of material resources on a planetary surface requires exploration strategies not dissimilar to those employed by early field geologists who searched for ore deposits primarily from surface clues. In order to determine the location of mineral ores or other materials, it will be necessary to characterize host terranes at regional or subregional scales. This requires geographically broad surveys in which statistically significant numbers of samples are rapidly scanned from a roving platform. To enable broad-scale, yet power-conservative planetary-surface exploration, we are developing an instrument that combines x-ray diffractometry (XRD), x-ray fluorescence spectrometry (XRF), and optical capabilities; the instrument can be deployed at the end of a rover's robotic arm, without the need for sample capture or preparation. The instrument provides XRD data for identification of mineral species and lithological types; diffractometry of minerals is conducted by ascertaining the characteristic lattice parameters or "d-spacings" of mineral compounds. D-spacings of 1.4 to 25 angstroms can be determined to include the large molecular structures of hydrated minerals such as clays. The XRF data will identify elements ranging from carbon (Atomic Number = 6) to elements as heavy as barium (Atomic Number = 56).

  7. Characterization by X-ray tomography of granulated alumina powder during in situ die compaction

    SciTech Connect

    Cottrino, Sandrine; Jorand, Yves Maire, Eric; Adrien, Jérôme

    2013-07-15

    Compaction process, the aim of which being to obtain green bodies with low porosity and small size, is often used before sintering treatment. Prior to die filling, the ceramic powder is generally granulated to improve flowability. However during compaction, density heterogeneity and critical size defects may appear due to intergranule and granule-die wall frictions. In this work, the influence of granule formulation on the compact morphology has been studied. To do so, a compaction setup was installed inside an X-ray tomography equipment so that the evolution of the compact morphology could be analysed during the whole compaction process. We have demonstrated that high humidity rate and the addition of binder in the granule formulation increase density heterogeneity and generate larger defects. - Highlights: • An original compaction set up was installed inside an X-Ray tomography equipment. • The compaction process of granulated ceramic powder is imaged. • The compact green microstructure is quantified and related to the compaction stages. • The most detrimental defects of dry-pressed parts are caused by hollow granules. • Formulations without binder allow a reduction of the number of large defects.

  8. In-situ X-ray structure measurements on aerodynamically levitated high temperature liquids

    SciTech Connect

    Weber, Richard; Benmore, Christopher; Mei Qiang; Wilding, Martin

    2009-01-29

    High energy, high flux X-ray sources enable new measurements of liquid and amorphous materials in extreme conditions. Aerodynamic levitation in combination with laser beam heating can be used to access high purity and non-equilibrium liquids at temperatures up to 3000 K. In this work, a small aerodynamic levitator was integrated with high energy beamline 11 ID-C at the Advanced Photon Source. Scattered X-rays were detected with a Mar345 image plate. The experiments investigated a series of binary in the CaO-Al{sub 2}O{sub 3}, MgO-SiO{sub 2}, SiO{sub 2}-Al{sub 2}O{sub 3} metal oxide compositions and pure SiO{sub 2}. The results show that the liquids exhibit large changes in structure when the predominant network former is diluted. Measurements on glasses with the same compositions as the liquids suggest that significant structural rearrangement consistent with a fragile-strong transition occurs in these reluctant glass forming liquids as they vitrify.

  9. In-situ X-ray Synchrotron Microtomography: Real Time Pore Structure Evolution during Olivine Carbonation

    NASA Astrophysics Data System (ADS)

    Zhu, W.; Fusseis, F.; Lisabeth, H. P.; Xiao, X.

    2013-12-01

    Mineral carbonation has been proposed as a promising method for long-term, secure sequestration of carbon dioxide. In porous rocks, fluid-rock interactions can significantly alter the pore space and thus exert important controls over the rate and extent of carbonation. We constructed an x-ray transparent pressure cell [Fusseis et al., 2013] to investigate the real time pore structure evolution during mineral carbonation in porous olivine aggregates. In each experiment, a sintered olivine sample was subjected to a confining pressure of 13 MPa and a pore pressure of 10 MPa, with a sodium bicarbonate solution (NaHCO3 at 1.5 M) as pore fluid. At these pressure conditions, the cell was heated to 473 K. Constant pressure and temperature conditions were maintained during the length of the experiments, lasting 72-120 hours. Using a polychromatic beam in the 2-BM upstream hutch at the Advanced Photon Source, 3-dimensional (3-D) microtomography data were collected in 20 seconds with 30-minute interval. A novel phase retrieval reconstruction algorithm [Paganin et al., 2002] was used to reconstruct microtomographic datasets with a voxel size of ~1.1 micron. The microtomography images at different stages of the carbonation process reveal progressive growth of new crystals in the pore space. Integration of a x-ray transparent pressure vessel with flow through capacity and 3-D microtomography provides a novel research direction of studying the coupled chemo-hydro-thermal-mechanical processes in rocks.

  10. In-situ high-pressure x-ray diffraction study of zinc ferrite nanoparticles

    NASA Astrophysics Data System (ADS)

    Ferrari, S.; Kumar, R. S.; Grinblat, F.; Aphesteguy, J. C.; Saccone, F. D.; Errandonea, D.

    2016-06-01

    We have studied the high-pressure structural behavior of zinc ferrite (ZnFe2O4) nanoparticles by powder X-ray diffraction measurements up to 47 GPa. We found that the cubic spinel structure of ZnFe2O4 remains up to 33 GPa and a phase transition is induced beyond this pressure. The high-pressure phase is indexed to an orthorhombic CaMn2O4-type structure. Upon decompression the low- and high-pressure phases coexist. The compressibility of both structures was also investigated. We have observed that the lattice parameters of the high-pressure phase behave anisotropically upon compression. Further, we predict possible phase transition around 55 GPa. For comparison, we also studied the compression behavior of magnetite (Fe3O4) nanoparticles by X-ray diffraction up to 23 GPa. Spinel-type ZnFe2O4 and Fe3O4 nanoparticles have a bulk modulus of 172 (20) GPa and 152 (9) GPa, respectively. This indicates that in both cases the nanoparticles do not undergo a Hall-Petch strengthening.

  11. In Situ Identification of Mineral Resources with an X-Ray-Optical "Hands-Lens" Instrument

    NASA Astrophysics Data System (ADS)

    Marshall, J.; Koppel, L.; Bratton, C.; Metzger, E.; Hecht, M.

    1999-09-01

    The recognition of material resources on a planetary surface requires exploration strategies not dissimilar to those employed by early field geologists who searched for ore deposits primarily from surface clues. In order to determine the location of mineral ores or other materials, it will be necessary to characterize host terranes at regional or subregional scales. This requires geographically broad surveys in which statistically significant numbers of samples are rapidly scanned from a roving platform. To enable broad-scale, yet power-conservative planetary-surface exploration, we are developing an instrument that combines x-ray diffractometry (XRD), x-ray fluorescence spectrometry (XRF), and optical capabilities; the instrument can be deployed at the end of a rover's robotic arm, without the need for sample capture or preparation. The instrument provides XRD data for identification of mineral species and lithological types; diffractometry of minerals is conducted by ascertaining the characteristic lattice parameters or "d-spacings" of mineral compounds. D-spacings of 1.4 to 25 angstroms can be determined to include the large molecular structures of hydrated minerals such as clays. The XRF data will identify elements ranging from carbon (Atomic Number = 6) to elements as heavy as barium (Atomic Number = 56). While a sample is being x-rayed, the instrument simultaneously acquires an optical image of the sample surface at magnifications from lx to at least 50x (200x being feasible, depending on the sample surface). We believe that imaging the sample is extremely important as corroborative sample-identification data (the need for this capability having been illustrated by the experience of the Pathfinder rover). Very few geologists would rely on instrument data for sample identification without having seen the sample. Visual inspection provides critical recognition data such as texture, crystallinity, granularity, porosity, vesicularity, color, lustre, opacity, and

  12. In Situ Identification of Mineral Resources with an X-Ray-Optical "Hands-Lens" Instrument

    NASA Technical Reports Server (NTRS)

    Marshall, J.; Koppel, L.; Bratton, C.; Metzger, E.; Hecht, M.

    1999-01-01

    The recognition of material resources on a planetary surface requires exploration strategies not dissimilar to those employed by early field geologists who searched for ore deposits primarily from surface clues. In order to determine the location of mineral ores or other materials, it will be necessary to characterize host terranes at regional or subregional scales. This requires geographically broad surveys in which statistically significant numbers of samples are rapidly scanned from a roving platform. To enable broad-scale, yet power-conservative planetary-surface exploration, we are developing an instrument that combines x-ray diffractometry (XRD), x-ray fluorescence spectrometry (XRF), and optical capabilities; the instrument can be deployed at the end of a rover's robotic arm, without the need for sample capture or preparation. The instrument provides XRD data for identification of mineral species and lithological types; diffractometry of minerals is conducted by ascertaining the characteristic lattice parameters or "d-spacings" of mineral compounds. D-spacings of 1.4 to 25 angstroms can be determined to include the large molecular structures of hydrated minerals such as clays. The XRF data will identify elements ranging from carbon (Atomic Number = 6) to elements as heavy as barium (Atomic Number = 56). While a sample is being x-rayed, the instrument simultaneously acquires an optical image of the sample surface at magnifications from lx to at least 50x (200x being feasible, depending on the sample surface). We believe that imaging the sample is extremely important as corroborative sample-identification data (the need for this capability having been illustrated by the experience of the Pathfinder rover). Very few geologists would rely on instrument data for sample identification without having seen the sample. Visual inspection provides critical recognition data such as texture, crystallinity, granularity, porosity, vesicularity, color, lustre, opacity, and

  13. In Situ Identification of Mineral Resources with an X-Ray-Optical "Hands-Lens" Instrument

    NASA Technical Reports Server (NTRS)

    Marshall, J.; Koppel, L.; Bratton, C.; Metzger, E.; Hecht, M.

    1999-01-01

    The recognition of material resources on a planetary surface requires exploration strategies not dissimilar to those employed by early field geologists who searched for ore deposits primarily from surface clues. In order to determine the location of mineral ores or other materials, it will be necessary to characterize host terranes at regional or subregional scales. This requires geographically broad surveys in which statistically significant numbers of samples are rapidly scanned from a roving platform. To enable broad-scale, yet power-conservative planetary-surface exploration, we are developing an instrument that combines x-ray diffractometry (XRD), x-ray fluorescence spectrometry (XRF), and optical capabilities; the instrument can be deployed at the end of a rover's robotic arm, without the need for sample capture or preparation. The instrument provides XRD data for identification of mineral species and lithological types; diffractometry of minerals is conducted by ascertaining the characteristic lattice parameters or "d-spacings" of mineral compounds. D-spacings of 1.4 to 25 angstroms can be determined to include the large molecular structures of hydrated minerals such as clays. The XRF data will identify elements ranging from carbon (Atomic Number = 6) to elements as heavy as barium (Atomic Number = 56). While a sample is being x-rayed, the instrument simultaneously acquires an optical image of the sample surface at magnifications from lx to at least 50x (200x being feasible, depending on the sample surface). We believe that imaging the sample is extremely important as corroborative sample-identification data (the need for this capability having been illustrated by the experience of the Pathfinder rover). Very few geologists would rely on instrument data for sample identification without having seen the sample. Visual inspection provides critical recognition data such as texture, crystallinity, granularity, porosity, vesicularity, color, lustre, opacity, and

  14. In Situ Identification of Mineral Resources with an X-Ray-Optical "Hands-Lens" Instrument

    NASA Astrophysics Data System (ADS)

    Marshall, J.; Koppel, L.; Bratton, C.; Metzger, E.; Hecht, M.

    1999-09-01

    The recognition of material resources on a planetary surface requires exploration strategies not dissimilar to those employed by early field geologists who searched for ore deposits primarily from surface clues. In order to determine the location of mineral ores or other materials, it will be necessary to characterize host terranes at regional or subregional scales. This requires geographically broad surveys in which statistically significant numbers of samples are rapidly scanned from a roving platform. To enable broad-scale, yet power-conservative planetary-surface exploration, we are developing an instrument that combines x-ray diffractometry (XRD), x-ray fluorescence spectrometry (XRF), and optical capabilities; the instrument can be deployed at the end of a rover's robotic arm, without the need for sample capture or preparation. The instrument provides XRD data for identification of mineral species and lithological types; diffractometry of minerals is conducted by ascertaining the characteristic lattice parameters or "d-spacings" of mineral compounds. D-spacings of 1.4 to 25 angstroms can be determined to include the large molecular structures of hydrated minerals such as clays. The XRF data will identify elements ranging from carbon (Atomic Number = 6) to elements as heavy as barium (Atomic Number = 56). While a sample is being x-rayed, the instrument simultaneously acquires an optical image of the sample surface at magnifications from lx to at least 50x (200x being feasible, depending on the sample surface). We believe that imaging the sample is extremely important as corroborative sample-identification data (the need for this capability having been illustrated by the experience of the Pathfinder rover). Very few geologists would rely on instrument data for sample identification without having seen the sample. Visual inspection provides critical recognition data such as texture, crystallinity, granularity, porosity, vesicularity, color, lustre, opacity, and

  15. Physical mechanisms of planetary core formation: Constraints from in-situ X-ray microtomography

    NASA Astrophysics Data System (ADS)

    Watson, H. C.; Van Deusen, J.; Shi, K.; Yu, T.; Wang, Y.

    2014-12-01

    Segregation of the metallic core from a silicate mantle is a crucial aspect of early planetary evolution. Although a magma ocean scenario is often used to explain differentiation of large planets such as Earth, smaller planets and planetesimals likely never achieved the high temperatures necessary for wide scale melting. In these smaller bodies, silicates may have only partially melted, or not melted at all. Furthermore, isotopic signatures in meteorites suggest that some planetesimals differentiated within just a few million years. Achieving core segregation on this time scale whereby core material drains through a solid silicate mantle via an interconnected network of melt faces two major problems: (1) in a hydrostatic situation, the percolation threshold is above 5 vol% melt, so the process would lead to inefficient core formation, and (2) the permeability of fully connected melts at microstructural equilibrium is low enough that some planetesimals may still not be able to differentiate on this short time scale. It has been suggested that shear deformation can cause isolated melt pockets to become connected even at low melt fractions. Here, we have measured the change in permeability of core forming melts in solid silicate and partially molten silicate matrix due to deformation. Mixtures of olivine or KLB-1 peridotite and FeS close to the equilibrium percolation threshold (~5 vol% FeS) were pre-synthesized to achieve an equilibrium microstructure, and then loaded into the high pressure X-ray tomography apparatus at GSECARS, sector 13-BMD, at the Advanced Photon Source (Argonne National Laboratory). The samples were then pressed to ~2GPa, and heated to ~1100°C. Alternating cycles of rotation to collect X-ray tomography images, and twisting to deform the sample were conducted. Starting materials and run products have also been analysed at high resolution in three dimensions using FIB/SEM cross-beam tools. Quantitative analyses have been performed on the resulting

  16. In situ X-ray nanotomography of metal surfaces during electropolishing

    DOE PAGESBeta

    Nave, Maryana I.; Allen, Jason P.; Karen Chen-Wiegart, Yu-chen; Wang, Jun; Kalidindi, Surya R.; Kornev, Konstantin G.

    2015-10-15

    A low voltage electropolishing of metal wires is attractive for nanotechnology because it provides centimeter long and micrometer thick probes with the tip radius of tens of nanometers. Using X-ray nanotomography we studied morphological transformations of the surface of tungsten wires in a specially designed electrochemical cell where the wire is vertically submersed into the KOH electrolyte. We show that stability and uniformity of the probe span is supported by a porous shell growing at the surface of tungsten oxide and shielding the wire surface from flowing electrolyte. We discovered that the kinetics of shell growth at the triple line,more » where meniscus meets the wire, is very different from that of the bulk of electrolyte. Many metals follow similar electrochemical transformations hence the discovered morphological transformations of metal surfaces are expected to play significant role in many natural and technological applications.« less

  17. In situ X-ray nanotomography of metal surfaces during electropolishing

    NASA Astrophysics Data System (ADS)

    Nave, Maryana I.; Allen, Jason P.; Karen Chen-Wiegart, Yu-Chen; Wang, Jun; Kalidindi, Surya R.; Kornev, Konstantin G.

    2015-10-01

    A low voltage electropolishing of metal wires is attractive for nanotechnology because it provides centimeter long and micrometer thick probes with the tip radius of tens of nanometers. Using X-ray nanotomography we studied morphological transformations of the surface of tungsten wires in a specially designed electrochemical cell where the wire is vertically submersed into the KOH electrolyte. It is shown that stability and uniformity of the probe span is supported by a porous shell growing at the surface of tungsten oxide and shielding the wire surface from flowing electrolyte. It is discovered that the kinetics of shell growth at the triple line, where meniscus meets the wire, is very different from that of the bulk of electrolyte. Many metals follow similar electrochemical transformations hence the discovered morphological transformations of metal surfaces are expected to play significant role in many natural and technological applications.

  18. In situ x-ray scattering studies of the Au(111)/electrolyte interface

    SciTech Connect

    Wang, Jia; Ocko, B.M.; Davenport, A.J.; Isaacs, H.S.

    1991-01-01

    The adsorption of anions at the Au(111) electrode and the subsequent effect on the gold surface structure have been investigated using x-ray specular reflectivity and grazing incident angle diffraction techniques. The top layer of gold atoms undergoes a reversible phase transition between the (1{times}1) bulk termination and a (23{times}{radical}{bar 3}) reconstructed phase on changing the potential. The shifts of the phase transition potential in NaCland NaBr solutions from the one in NaF can be understood by the anion adsorption induced charge effect. The reconstruction formation rate increases in chloride and bromide solutions due to an increase in the surface mobility with anion adsorption. Adsorbed chloride and bromide monolayers can be monitored during a potential scan by the specular reflectivity.

  19. In situ x-ray scattering studies of the Au(111)/electrolyte interface

    SciTech Connect

    Wang, Jia; Ocko, B.M.; Davenport, A.J.; Isaacs, H.S.

    1991-12-31

    The adsorption of anions at the Au(111) electrode and the subsequent effect on the gold surface structure have been investigated using x-ray specular reflectivity and grazing incident angle diffraction techniques. The top layer of gold atoms undergoes a reversible phase transition between the (1{times}1) bulk termination and a (23{times}{radical}{bar 3}) reconstructed phase on changing the potential. The shifts of the phase transition potential in NaCland NaBr solutions from the one in NaF can be understood by the anion adsorption induced charge effect. The reconstruction formation rate increases in chloride and bromide solutions due to an increase in the surface mobility with anion adsorption. Adsorbed chloride and bromide monolayers can be monitored during a potential scan by the specular reflectivity.

  20. In situ X-ray nanotomography of metal surfaces during electropolishing

    SciTech Connect

    Nave, Maryana I.; Allen, Jason P.; Karen Chen-Wiegart, Yu-chen; Wang, Jun; Kalidindi, Surya R.; Kornev, Konstantin G.

    2015-10-15

    A low voltage electropolishing of metal wires is attractive for nanotechnology because it provides centimeter long and micrometer thick probes with the tip radius of tens of nanometers. Using X-ray nanotomography we studied morphological transformations of the surface of tungsten wires in a specially designed electrochemical cell where the wire is vertically submersed into the KOH electrolyte. We show that stability and uniformity of the probe span is supported by a porous shell growing at the surface of tungsten oxide and shielding the wire surface from flowing electrolyte. We discovered that the kinetics of shell growth at the triple line, where meniscus meets the wire, is very different from that of the bulk of electrolyte. Many metals follow similar electrochemical transformations hence the discovered morphological transformations of metal surfaces are expected to play significant role in many natural and technological applications.

  1. In situ X-ray nanotomography of metal surfaces during electropolishing

    PubMed Central

    Nave, Maryana I.; Allen, Jason P.; Karen Chen-Wiegart, Yu-chen; Wang, Jun; Kalidindi, Surya R.; Kornev, Konstantin G.

    2015-01-01

    A low voltage electropolishing of metal wires is attractive for nanotechnology because it provides centimeter long and micrometer thick probes with the tip radius of tens of nanometers. Using X-ray nanotomography we studied morphological transformations of the surface of tungsten wires in a specially designed electrochemical cell where the wire is vertically submersed into the KOH electrolyte. It is shown that stability and uniformity of the probe span is supported by a porous shell growing at the surface of tungsten oxide and shielding the wire surface from flowing electrolyte. It is discovered that the kinetics of shell growth at the triple line, where meniscus meets the wire, is very different from that of the bulk of electrolyte. Many metals follow similar electrochemical transformations hence the discovered morphological transformations of metal surfaces are expected to play significant role in many natural and technological applications. PMID:26469184

  2. Characterization of Cathode Materials for Rechargeable Lithium Batteries using Synchrotron Based In Situ X-ray Techniques

    SciTech Connect

    Yang, Xiao-Qing

    2007-05-23

    not be representative for the full picture of the structural changes during charge (discharge). In other words, the important information might be missed for those charge (discharge) states which were not selected for ex situ XRD studies. Secondly, the structure of the sample may have changed after removed from the cell. Finally, it is impossible to use the ex situ XRD to study the dynamic effects during high rate charge-discharge, which is crucial for the application of lithium-ion batteries for electric vehicle. A few in situ studies have been done using conventional x-ray tube sources. All of the in situ XRD studies using conventional x-ray tube sources have been done in the reflection mode in cells with beryllium windows. Because of the weak signals, data collection takes a long time, often several hundred hours for a single charge-discharge cycle. This long time data collection is not suitable for dynamic studies at all. Furthermore, in the reflection mode, the x-ray beam probes mainly the surface layer of the cathode materials. Iri collaboration with LG Chemical Ltd., BNL group designed and constructed the cells for in situ studies. LG Chemical provided several blended samples and pouch cells to BNL for preliminary in situ study. The LG Chemical provided help on integrate the blended cathode into these cells. The BNL team carried out in situ XAS and XRD studies on the samples and pouch cells provided by LG Chemical under normal charge-discharge conditions at elevated temperature.

  3. In situ characterization of Grade 92 steel during tensile deformation using concurrent high energy X-ray diffraction and small angle X-ray scattering

    NASA Astrophysics Data System (ADS)

    Wang, Leyun; Li, Meimei; Almer, Jonathan

    2013-09-01

    The tensile deformation in Grade 92 steel was studied in situ using simultaneous high energy X-ray diffraction (HE-XRD), radiography, and small angle X-ray scattering (SAXS) at room temperature (RT), 400, and 650 °C. Temperature-dependent elastic properties, i.e. Young's modulus and Poisson's ratio, were measured for α-Fe matrix, M23C6 and Nb(C,N) phases in various crystallographic orientation. Significant differences in the evolution of lattice strain, peak broadening/sharpening, and void development in the α-Fe matrix, M23C6 and Nb(C,N) precipitates revealed markedly different deformation and damage mechanisms at low and high temperature in the alloy. The strengthening effect of each type of precipitates measured by lattice strain agrees with the dislocation pile-up model at room temperature, while a different dislocation behavior was observed at 650 °C. Void volume fraction as a function of strain measured by SAXS can be described by a classic void nucleation and growth model at room temperature but not at 650 °C, implying a different damage process at high temperature. The ultimate tensile strength is ordered as RT > 400 °C > 650 °C; strain to failure is ordered as 650 °C > RT > 400 °C. For the 650 °C test, there was a long softening stage between the UTS and specimen necking. M23C6 and Nb(C,N) precipitates were identified in the Fe matrix. At RT and 400 °C, apparent load transfer from the matrix to the precipitates took place after the matrix's early yielding. Measured von Mises stresses in the precipitates can be quantitatively explained using the established models of precipitate strengthening. Increase of dislocation density with deformation caused peak broadening in both matrix and precipitates. At 650 °C, load transfer was much less, and peak broadening was also largely subdued at 650 °C. Anisotropy of lattice strains was observed both in the matrix and precipitates. The elastic modulus of Fe (2 0 0) is lower than Fe (2 1 1) and Fe (2 2 0

  4. Enhanced water window x-ray emission from in situ formed carbon clusters irradiated by intense ultra-short laser pulses

    SciTech Connect

    Chakravarty, U.; Rao, B. S.; Arora, V.; Upadhyay, A.; Singhal, H.; Naik, P. A.; Chakera, J. A.; Mukherjee, C.; Gupta, P. D.

    2013-07-29

    Enhanced water window x-ray emission (23–44 Å) from carbon clusters, formed in situ using a pre-pulse, irradiated by intense (I > 10{sup 17} W/cm{sup 2}) ultra-short laser pulse, is demonstrated. An order of magnitude x-ray enhancement over planar graphite target is observed in carbon clusters, formed by a sub-ns pre-pulse, interacting with intense main pulse after a delay. The effect of the delay and the duration of the main pulse is studied for optimizing the x-ray emission in the water window region. This x-ray source has added advantages of being an efficient, high repetition rate, and low debris x-ray source.

  5. Hydrothermal synthesis of nanocrystalline ZnSe: An in situ synchrotron radiation X-ray powder diffraction study

    SciTech Connect

    Jorgensen, J.-E. Jensen, T.R.; Hanson, J.C.

    2008-08-15

    The hydrothermal synthesis of nanocrystalline ZnSe has been studied by in situ X-ray powder diffraction using synchrotron radiation. The formation of ZnSe was studied using the following starting mixtures: Zn+Se+H{sub 2}O (route A) and ZnCl{sub 2}+Se+H{sub 2}O+Na{sub 2}SO{sub 3} (route B). The route A experiment showed that Zn powder starts reacting with water at 134 deg. C giving ZnO and H{sub 2} followed by the formation of ZnSe which takes place in temperature range from 167 to 195 deg. C. The route B experiment shows a considerably more complex reaction path with several intermediate phases and in this case the formation of ZnSe starts at 141 deg. C and ZnSe and Se were the only crystalline phases observed at the end of the experiment where the temperature was 195 deg. C. The sizes of the nanocrystalline particles were determined to 18 and 9 nm in the route A and B experiments, respectively. Nanocrystalline ZnSe was also synthesized ex situ using the route A and B methods and characterized by conventional X-ray powder diffraction and transmission electron microscopy. An average crystalline domain size of ca. 8 nm was determined by X-ray powder diffraction in fair agreement with TEM images, which showed larger aggregates of nanoparticles having approximate diameters of 10 nm. Furthermore, a method for purification of the ZnSe nanoparticles was developed and the prepared particles showed signs of anisotropic size broadening of the diffraction peaks. - Graphical abstract: Stack of powder diagrams showing the formation of nanocrystalline ZnSe under hydrothermal conditions.

  6. Hydrothermal Synthesis of Nanocrystalline ZnSe: An in situ Synchrotron Radiation X-ray Powder Diffraction Study

    SciTech Connect

    Joergensen,J.; Jensen, T.; Hanson, J.

    2008-01-01

    The hydrothermal synthesis of nanocrystalline ZnSe has been studied by in situ X-ray powder diffraction using synchrotron radiation. The formation of ZnSe was studied using the following starting mixtures: Zn+Se+H2O (route A) and ZnCl2+Se+H2O+Na2SO3 (route B). The route A experiment showed that Zn powder starts reacting with water at 134 C giving ZnO and H2 followed by the formation of ZnSe which takes place in temperature range from 167 to 195 C. The route B experiment shows a considerably more complex reaction path with several intermediate phases and in this case the formation of ZnSe starts at 141 C and ZnSe and Se were the only crystalline phases observed at the end of the experiment where the temperature was 195 C. The sizes of the nanocrystalline particles were determined to 18 and 9 nm in the route A and B experiments, respectively. Nanocrystalline ZnSe was also synthesized ex situ using the route A and B methods and characterized by conventional X-ray powder diffraction and transmission electron microscopy. An average crystalline domain size of ca. 8 nm was determined by X-ray powder diffraction in fair agreement with TEM images, which showed larger aggregates of nanoparticles having approximate diameters of 10 nm. Furthermore, a method for purification of the ZnSe nanoparticles was developed and the prepared particles showed signs of anisotropic size broadening of the diffraction peaks.

  7. Analysis of heat-affected zone phase transformations using in situ spatially resolved x-ray diffraction with synchrotron radiation

    SciTech Connect

    Elmer, J.W.; Wong, J.; Froeba, M.; Waide, P.A.; Larson, E.M.

    1996-03-01

    Spatially resolved X-ray diffraction (SRXRD) consists of producing a submillimeter size X-ray beam from an intense synchrotron radiation source to perform real-time diffraction measurements on solid materials. This technique was used int his study to investigate the crystal phases surrounding a liquid weld pool in commercial purity titanium and to determine the location of the phase boundary separating the high-temperature body-centered-cubic (bcc) {beta} phase from the low-temperature hexagonal-close-packed (hcp) {alpha} phase. The experiments were carried out at the Stanford Synchrotron Radiation Laboratory (SSRL) using a 0.25 x 0.50 mm X-ray probe that could be positioned with 10-{micro}m precision on the surface of a quasistationary gas tungsten arc weld (GTAW). The SRXRD results showed characteristic hcp, bcc, and liquid diffraction patterns at various points along the sample, starting from the base metal through the heat-affected zone (HAZ) and into the weld pool, respectively. Analyses of the SRXRD data show the coexistence of bcc and hcp phases in the partially transformed (outer) region of the HAZ and single-phase bcc in the fully transformed (inner) region of the HAZ. Postweld metallographic examinations of the HAZ, combined with a conduction-based thermal model of the weld, were correlated with the SRXRD results. Finally, analysis of the diffraction intensities of the hcp and bcc phases was performed on the SRXRD data to provide additional information about the microstructural conditions that may exist in the HAZ at temperature during welding. This work represents the first direct in situ mapping of phase boundaries in fusion welds.

  8. A Team Approach to the Development of Gamma Ray and x Ray Remote Sensing and in Situ Spectroscopy for Planetary Exploration Missions

    NASA Technical Reports Server (NTRS)

    Trombka, J. I.; Floyd, S.; Ruitberg, A.; Evans, L.; Starr, R.; Metzger, A.; Reedy, R.; Drake, D.; Moss, C.; Edwards, B.

    1993-01-01

    An important part of the investigation of planetary origin and evolution is the determination of the surface composition of planets, comets, and asteroids. Measurements of discrete line X-ray and gamma ray emissions from condensed bodies in space can be used to obtain both qualitative and quantitative elemental composition information. The Planetary Instrumentation Definition and Development Program (PIDDP) X-Ray/Gamma Ray Team has been established to develop remote sensing and in situ technologies for future planetary exploration missions.

  9. InSitu X-Ray Diffraction Studies on Lithium-Ion Battery Cathodes

    SciTech Connect

    Doughty, Daniel H.; Ingersoll, David; Rodriguez, Mark A.

    1999-07-13

    LiNi{sub 0.8}Co{sub 0.2}O{sub 2} and LiNiO{sub 2} have been characterized in-situ XRD. LiNi{sub 0.8}Co{sub 0.2}O{sub 2} does not undergo a monoclinic phase transformation but remains a hexagonal lattice throughout the entire charging cycle. It is hypothesized that Co-doping may help stabilize the hexagonal structure.

  10. Structure of jadeite-diopside melts at high pressure by in situ x-ray diffraction

    NASA Astrophysics Data System (ADS)

    Sakamaki, T.; Wang, Y.; Yu, T.; Park, C.; Shen, G.

    2010-12-01

    O and boron-epoxy. The center of the pressure medium was boron-epoxy and MgO, because of their low absorption to X-rays. The incident X-ray was collimated by a vertical slit (0.5 mm) and a horizontal slit (0.1 mm) to irradiate the sample. The diffracted X-ray was detected by a Ge solid state detector with a 4000 multi-channel analyzer, through vertical (0.5 mm) and horizontal (0.1 mm) receiving slits as well as a collimator. The diffraction patterns were collected for 12 fixed diffraction angles (2theta=3, 4, 5, 7, 9, 11, 15, 20, 25, 30, 35, 39.5 degrees). The structure measurements of jadeite-diopside melt were carried out in the pressure range from 1 to 5 GPa and at 1600 to 2000 K. Results on structure factors S(Q) and radial distribution functions G(r) of these melts at high pressures and high temperatures will be discussed.

  11. Tuning of colossal dielectric constant in gold-polypyrrole composite nanotubes using in-situ x-ray diffraction techniques

    SciTech Connect

    Sarma, Abhisakh; Sanyal, Milan K.

    2014-09-15

    In-situ x-ray diffraction technique has been used to study the growth process of gold incorporated polypyrrole nanotubes that exhibit colossal dielectric constant due to existence of quasi-one-dimensional charge density wave state. These composite nanotubes were formed within nanopores of a polycarbonate membrane by flowing pyrrole monomer from one side and mixture of ferric chloride and chloroauric acid from other side in a sample cell that allows collection of x-ray data during the reaction. The size of the gold nanoparticle embedded in the walls of the nanotubes was found to be dependent on chloroauric acid concentration for nanowires having diameter more than 100 nm. For lower diameter nanotubes the nanoparticle size become independent of chloroauric acid concentration and depends on the diameter of nanotubes only. The result of this study also shows that for 50 nm gold-polypyrrole composite nanotubes obtained with 5.3 mM chloroauric acid gives colossal dielectric constant of about 10{sup 7}. This value remain almost constant over a frequency range from 1Hz to 10{sup 6} Hz even at 80 K temperature.

  12. In-Situ X-ray Deformation Study of Fluorinated Mulitwalled Carbon Nanotube and Fluorinated Ethylene-Propylene Nanocomposite Fibers

    SciTech Connect

    Chen,X.; Burger, C.; Fang, D.; Sics, I.; Wang, X.; He, W.; Somani, R.; Yoon, K.; Hsiao, B.; Chu, B.

    2006-01-01

    A fluorinated multiwalled carbon nanotube (FMWNT) was prepared by reaction of 3-perfluorooctylpropylamine with carboxylic acid groups on the oxidized carbon nanotube surface. The modification was confirmed by TGA, TEM, and solubility tests in a perfluorodecalin solvent. Nanocomposite fibers based on FMWNT and a fluoro-ethylene-propylene (FEP) copolymer were fabricated by melt blending and melt spinning. SEM examination indicated that the dispersion of FMWNT in FEP was significantly better than that of the as-received multiwalled carbon nanotube (MWNT) in FEP. Both yield strength and modulus of the melt-spun FMWNT/FEP nanocomposite fiber increased with increasing FMWNT content, but the elongation-to-break ratio decreased. In-situ small-angle X-ray scattering (SAXS) and wide-angle X-ray diffraction (WAXD) techniques were used to follow the structural changes during tensile deformation of melt-spun fibers. In pure FEP fibers, perpendicularly arranged lamellar stacks (with respect to the fiber axis) became tilted at small strains, while destruction of lamellae took place at high strains (>250%), resulting in the rapid decrease of crystallinity. Surprisingly, the tilting of lamellar stacks was not observed in FEP/FMWNT nanocomposite fibers during deformation. We hypothesize that the well-dispersed FMWNT particles form a fibrous network, which can carry a significant fraction of local stress, resulting in overall increases of yield strength and modulus. A possible mechanism to explain the effect of FMWNT on the lamellar structural change in FEP and corresponding mechanical behavior is presented.

  13. In situ X-ray studies of adlayer-induced crystal nucleation at the liquid–liquid interface

    PubMed Central

    Elsen, Annika; Festersen, Sven; Runge, Benjamin; Koops, Christian T.; Ocko, Benjamin M.; Deutsch, Moshe; Seeck, Oliver H.; Murphy, Bridget M.; Magnussen, Olaf M.

    2013-01-01

    Crystal nucleation and growth at a liquid–liquid interface is studied on the atomic scale by in situ Å-resolution X-ray scattering methods for the case of liquid Hg and an electrochemical dilute electrolyte containing Pb2+, F−, and Br− ions. In the regime negative of the Pb amalgamation potential V, no change is observed from the surface-layered structure of pure Hg. Upon potential-induced release of Pb2+ from the Hg bulk at , the formation of an intriguing interface structure is observed, comprising a well-defined 7.6-Å–thick adlayer, decorated with structurally related 3D crystallites. Both are identified by their diffraction peaks as PbFBr, preferentially aligned with their axis along the interface normal. X-ray reflectivity shows the adlayer to consist of a stack of five ionic layers, forming a single-unit-cell–thick crystalline PbFBr precursor film, which acts as a template for the subsequent quasiepitaxial 3D crystal growth. This growth behavior is assigned to the combined action of electrostatic and short-range chemical interactions. PMID:23553838

  14. Multiferroic CuCrO₂ under high pressure: In situ X-ray diffraction and Raman spectroscopic studies

    SciTech Connect

    Garg, Alka B. Mishra, A. K.; Pandey, K. K.; Sharma, Surinder M.

    2014-10-07

    The compression behavior of delafossite compound CuCrO₂ has been investigated by in situ x-ray diffraction (XRD) and Raman spectroscopic measurements up to 23.2 and 34 GPa, respectively. X-ray diffraction data show the stability of ambient rhombohedral structure up to ~23 GPa. Material shows large anisotropy in axial compression with c-axis compressibility, κ{sub c} = 1.26 × 10⁻³(1) GPa⁻¹ and a-axis compressibility, κ{sub a} = 8.90 × 10⁻³(6) GPa⁻¹. Our XRD data show an irreversible broadening of diffraction peaks. Pressure volume data when fitted to 3rd order Birch-Murnaghan equation of state give the value of bulk modulus, B₀ = 156.7(2.8) GPa with its pressure derivative, B₀{sup ’} as 5.3(0.5). All the observed vibrational modes in Raman measurements show hardening with pressure. Appearance of a new mode at ~24 GPa indicates the structural phase transition in the compound. Our XRD and Raman results indicate that CuCrO{sub 2} may be transforming to an ordered rocksalt type structure under compression.

  15. In situ and real-time monitoring of mechanochemical milling reactions using synchrotron X-ray diffraction.

    PubMed

    Halasz, Ivan; Kimber, Simon A J; Beldon, Patrick J; Belenguer, Ana M; Adams, Frank; Honkimäki, Veijo; Nightingale, Richard C; Dinnebier, Robert E; Friščić, Tomislav

    2013-09-01

    We describe the only currently available protocol for in situ, real-time monitoring of mechanochemical reactions and intermediates by X-ray powder diffraction. Although mechanochemical reactions (inducing transformations by mechanical forces such as grinding and milling) are normally performed in commercially available milling assemblies, such equipment does not permit direct reaction monitoring. We now describe the design and in-house modification of milling equipment that allows the reaction jars of the operating mill to be placed in the path of a high-energy (∼90 keV) synchrotron X-ray beam while the reaction is taking place. Resulting data are analyzed using conventional software, such as TOPAS. Reaction intermediates and products are identified using the Cambridge Structural Database or Inorganic Crystal Structure Database. Reactions are analyzed by fitting the time-resolved diffractograms using structureless Pawley refinement for crystalline phases that are not fully structurally characterized (such as porous frameworks with disordered guests), or the Rietveld method for solids with fully determined crystal structures (metal oxides, coordination polymers). PMID:23949378

  16. In situ x-ray-absorption spectroscopy study of hydrogen absorption by nickel-magnesium thin films

    NASA Astrophysics Data System (ADS)

    Farangis, B.; Nachimuthu, P.; Richardson, T. J.; Slack, J. L.; Perera, R. C.; Gullikson, E. M.; Lindle, D. W.; Rubin, M.

    2003-02-01

    Structural and electronic properties of co-sputtered Ni-Mg thin films with varying Ni to Mg ratio were studied by in situ x-ray absorption spectroscopy in the Ni L-edge and Mg K-edge regions. Codeposition of the metals led to increased disorder and decreased coordination around Ni and Mg compared to pure metal films. Exposure of the metallic films to hydrogen resulted in formation of hydrides and increased disorder. The presence of hydrogen as a near neighbor around Mg caused a drastic reduction in the intensities of multiple scattering resonances at higher energies. The optical switching behavior and changes in the x-ray spectra varied with Ni to Mg atomic ratio. Pure Mg films with Pd overlayers were converted to MgH2: The H atoms occupy regular sites as in bulk MgH2. Although optical switching was slow in the absence of Ni, the amount of H2 absorption was large. Incorporation of Ni in Mg films led to an increase in the speed of optical switching but decreased maximum transparency. Significant shifts in the Ni L3 and L2 peaks are consistent with strong interaction with hydrogen in the mixed films.

  17. Aerodynamic levitator for in situ x-ray structure measurements on high temperature and molten nuclear fuel materials.

    PubMed

    Weber, J K R; Tamalonis, A; Benmore, C J; Alderman, O L G; Sendelbach, S; Hebden, A; Williamson, M A

    2016-07-01

    An aerodynamic levitator with carbon dioxide laser beam heating was integrated with a hermetically sealed controlled atmosphere chamber and sample handling mechanism. The system enabled containment of radioactive samples and control of the process atmosphere chemistry. The chamber was typically operated at a pressure of approximately 0.9 bars to ensure containment of the materials being processed. Samples 2.5-3 mm in diameter were levitated in flowing gas to achieve containerless conditions. Levitated samples were heated to temperatures of up to 3500 °C with a partially focused carbon dioxide laser beam. Sample temperature was measured using an optical pyrometer. The sample environment was integrated with a high energy (100 keV) x-ray synchrotron beamline to enable in situ structure measurements to be made on levitated samples as they were heated, melted, and supercooled. The system was controlled from outside the x-ray beamline hutch by using a LabVIEW program. Measurements have been made on hot solid and molten uranium dioxide and binary uranium dioxide-zirconium dioxide compositions. PMID:27475566

  18. In situ Rheological Measurements at Extreme Pressure and Temperature using Synchrotron X-ray Diffraction and Radiography

    SciTech Connect

    Raterron, P.; Merkel, S

    2009-01-01

    Dramatic technical progress seen over the past decade now allows the plastic properties of materials to be investigated under extreme pressure and temperature conditions. Coupling of high-pressure apparatuses with synchrotron radiation significantly improves the quantification of differential stress and specimen textures from X-ray diffraction data, as well as specimen strains and strain rates by radiography. This contribution briefly reviews the recent developments in the field and describes state-of-the-art extreme-pressure deformation devices and analytical techniques available today. The focus here is on apparatuses promoting deformation at pressures largely in excess of 3 GPa, namely the diamond anvil cell, the deformation-DIA apparatus and the rotational Drickamer apparatus, as well as on the methods used to carry out controlled deformation experiments while quantifying X-ray data in terms of materials rheological parameters. It is shown that these new techniques open the new field of in situ investigation of materials rheology at extreme conditions, which already finds multiple fundamental applications in the understanding of the dynamics of Earth-like planet interior.

  19. In situ hard x-ray photoemission spectroscopy of barrier-height control at metal/PMN-PT interfaces

    NASA Astrophysics Data System (ADS)

    Kröger, E.; Petraru, A.; Quer, A.; Soni, R.; Kalläne, M.; Pertsev, N. A.; Kohlstedt, H.; Rossnagel, K.

    2016-06-01

    Metal-ferroelectric interfaces form the basis of novel electronic devices. A key effect determining the device functionality is the bias-dependent change of the electronic energy-level alignment at the interface. Here, hard x-ray photoelectron spectroscopy (HAXPES) is used to determine the energy-level alignment at two metal-ferroelectric interfaces—Au versus SrRuO3 on the relaxor ferroelectric Pb (Mg1 /3Nb2 /3 )0.72Ti0.28O3 (PMN-PT)—directly in situ as a function of electrical bias. The bias-dependent average shifts of the PMN-PT core levels are found to have two dominant contributions on the 0.1 -1-eV energy scale: one depending on the metal electrode and the remanent electric polarization and the other correlated with electric-field-induced strain. Element-specific deviations from the average shifts are smaller than 0.1 eV and appear to be related to predicted dynamical charge variations in PMN-PT. In addition, the efficiency of ferroelectric polarization switching is shown to be reduced near the coercive field under x-ray irradiation. The results establish HAXPES as a tool for the in operando investigation of metal-ferroelectric interfaces and suggest electric-field-induced modifications of the polarization distribution as a novel way to control the barrier height at such interfaces.

  20. Ultra-fast in-situ X-ray studies of evolving columnar dendrites in solidifying steel weld pools

    NASA Astrophysics Data System (ADS)

    Mirihanage, W. U.; Di Michiel, M.; Mathiesen, R. H.

    2015-06-01

    High-brilliance polychromatic synchrotron radiation has been used to conduct in-situ studies of the solidification microstructure evolution during simulated welding. The welding simulations were realized by rapidly fusing ∼ 5 mm spot in Fe-Cr-Ni steel. During the solid- liquid-solid phase transformations, a section of the weld pool was placed in an incident 50-150 keV polychromatic synchrotron X-ray beam, in a near-horizontal position at a very low inclination angle. Multiple high-resolution 2D detectors with very high frame rates were utilized to capture time resolved X-ray diffraction data from suitably oriented solid dendrites evolving in the weld pool. Comprehensive analysis of the diffraction data revealed individual and overall dendritic growth characteristics and relevant melt and solid flow dynamics during weld pool solidification, which was completed within 1.5 s. Columnar dendrite tip velocities were estimated from the experimental data and during early stages of solidification were exceeded 4 mm/s. The most remarkable observation revealed through the time-resolved reciprocal space observations are correlated to significant tilting of columnar type dendrites at their root during solidification, presumably caused by convective currents in the weld pool. When the columnar dendrite tilting are transformed to respective metric linear tilting velocities at the dendrite tip; tilting velocities are found to be in the same order of magnitude as the columnar tip growth velocities, suggesting a highly transient nature of growth conditions.

  1. Aerodynamic levitator for in situ x-ray structure measurements on high temperature and molten nuclear fuel materials

    NASA Astrophysics Data System (ADS)

    Weber, J. K. R.; Tamalonis, A.; Benmore, C. J.; Alderman, O. L. G.; Sendelbach, S.; Hebden, A.; Williamson, M. A.

    2016-07-01

    An aerodynamic levitator with carbon dioxide laser beam heating was integrated with a hermetically sealed controlled atmosphere chamber and sample handling mechanism. The system enabled containment of radioactive samples and control of the process atmosphere chemistry. The chamber was typically operated at a pressure of approximately 0.9 bars to ensure containment of the materials being processed. Samples 2.5-3 mm in diameter were levitated in flowing gas to achieve containerless conditions. Levitated samples were heated to temperatures of up to 3500 °C with a partially focused carbon dioxide laser beam. Sample temperature was measured using an optical pyrometer. The sample environment was integrated with a high energy (100 keV) x-ray synchrotron beamline to enable in situ structure measurements to be made on levitated samples as they were heated, melted, and supercooled. The system was controlled from outside the x-ray beamline hutch by using a LabVIEW program. Measurements have been made on hot solid and molten uranium dioxide and binary uranium dioxide-zirconium dioxide compositions.

  2. In situ X-ray studies of adlayer-induced crystal nucleation at the liquid-liquid interface

    SciTech Connect

    Elsen, Annika; Festersen, Sven; Runge, Benjamin; Koops, Christian T.; Ocko, Benjamin M.; Deutsch, Moshe; Seeck, Oliver H.; Murphy, Bridget M.; Magnussen, Olaf M.

    2013-05-29

    Crystal nucleation and growth at a liquid–liquid interface is studied on the atomic scale by in situ Å-resolution X-ray scattering methods for the case of liquid Hg and an electrochemical dilute electrolyte containing Pb2+, F-, and Br- ions. In the regime negative of the Pb amalgamation potential Φrp = -0.70 V, no change is observed from the surface-layered structure of pure Hg. Upon potential-induced release of Pb2+ from the Hg bulk at Graphic, the formation of an intriguing interface structure is observed, comprising a well-defined 7.6-Å–thick adlayer, decorated with structurally related 3D crystallites. Both are identified by their diffraction peaks as PbFBr, preferentially aligned with their Graphic axis along the interface normal. X-ray reflectivity shows the adlayer to consist of a stack of five ionic layers, forming a single-unit-cell–thick crystalline PbFBr precursor film, which acts as a template for the subsequent quasiepitaxial 3D crystal growth. This growth behavior is assigned to the combined action of electrostatic and short-range chemical interactions.

  3. Mechanisms Determining the Structure of Gold-Catalyzed GaAs Nanowires Studied by in Situ X-ray Diffraction

    SciTech Connect

    Takahasi, Masamitu; Kozu, Miwa; Sasaki, Takuo; Hu, Wen

    2015-09-02

    The evolution of polytypism during GaAs nanowire growth was investigated with in situ X-ray diffraction. The growth of nanowires was found to start with the formation of zincblende structure, followed by the growth of wurtzite structure. The growth process was well reproduced by a simulation based on a layer-by-layer nucleation model. The good agreement between the measured and simulated results confirms that nucleation costs higher energy for the stackings changing the crystal structure than for those conserving the preceding structure. The transition in prevalent structure can be accounted for by the change of local growth conditions related to the shape of triple phase line rather than by the change in supersaturation level, which quickly reaches steady state after starting growth.

  4. In Situ Synchrotron X-ray Diffraction Measurement of the Strain Distribution in Si Die for the Embedded Substrates

    NASA Astrophysics Data System (ADS)

    Hsu, Hsueh Hsien; Chen, Hao; Ouyang, Yao Tsung; Chiu, Tz Cheng; Chang, Tao Chih; Lee, Hsin Yi; Ku, Chin Shun; Wu, Albert T.

    2015-10-01

    Three-dimensional packaging provides an acceptable solution for miniaturized integrated circuits. Because of the technological flexibility required for combining various modules to form a functional system, miniaturization can be achieved by using embedded techniques that could enhance the reliability of assembled systems. Because the mismatch of the thermal expansion coefficient among the materials has been an emerging issue when embedded components are subjected to thermal cycles, this study adopted the in situ synchrotron x-ray method to measure the strain distribution of a Si die in embedded substrates at various temperatures ranging from 25°C to 150°C. The out-of-plane strain of the Si die became less compressive when the temperature was increased. The numerical simulation of the finite elements software ANSYS also indicated the similar consequence of the strain behavior.

  5. Versatile plug flow catalytic cell for in situ transmission/fluorescence x-ray absorption fine structure measurements

    NASA Astrophysics Data System (ADS)

    Centomo, P.; Meneghini, C.; Zecca, M.

    2013-05-01

    A novel flow-through catalytic cell has been developed for in situ x-ray absorption spectroscopy (XAS) experiments on heterogeneous catalysts under working conditions and in the presence of a liquid and a gas phase. The apparatus allows to carry out XAS measurements in both the transmission and fluorescence modes, at moderate temperature (from RT to 50-80 °C) and low-medium gas pressure (up to 7-8 bars). The materials employed are compatible with several chemicals such as those involved in the direct synthesis of hydrogen peroxide (O2, H2, H2O2, methanol). The versatile design of the cell allows to fit it to different experimental setups in synchrotron radiation beamlines. It was used successfully for the first time to test nanostructured Pd catalysts during the direct synthesis of hydrogen peroxide (H2O2) in methanol solution from dihydrogen and dioxygen.

  6. Observation of localized heating phenomena during microwave heating of mixed powders using in situ x-ray diffraction technique

    SciTech Connect

    Sabelström, N. Hayashi, M.; Watanabe, T.; Nagata, K.

    2014-10-28

    In materials processing research using microwave heating, there have been several observations of various phenomena occurring known as microwave effects. One significant example of such a phenomenon is increased reaction kinetics. It is believed that there is a possibility that this might be caused by localized heating, were some reactants would attain a higher than apparent temperature. To examine whether such thermal gradients are indeed possible, mixed powders of two microwave non-absorbers, alumina and magnesia, were mixed with graphite, a known absorber, and heated in a microwave furnace. During microwave irradiation, the local temperatures of the respective sample constituents were measured using an in situ x-ray diffraction technique. In the case of the alumina and graphite sample, a temperature difference of around 100 °C could be observed.

  7. Structure of Carbon Nanotube Porins in Lipid Bilayers: An in Situ Small-Angle X-ray Scattering (SAXS) Study.

    PubMed

    Tran, Ich C; Tunuguntla, Ramya H; Kim, Kyunghoon; Lee, Jonathan R I; Willey, Trevor M; Weiss, Thomas M; Noy, Aleksandr; van Buuren, Tony

    2016-07-13

    Carbon nanotube porins (CNTPs), small segments of carbon nanotubes capable of forming defined pores in lipid membranes, are important future components for bionanoelectronic devices as they could provide a robust analog of biological membrane channels. In order to control the incorporation of these CNT channels into lipid bilayers, it is important to understand the structure of the CNTPs before and after insertion into the lipid bilayer as well as the impact of such insertion on the bilayer structure. Here we employed a noninvasive in situ probe, small-angle X-ray scattering, to study the integration of CNT porins into dioleoylphosphatidylcholine bilayers. Our results show that CNTPs in solution are stabilized by a monolayer of lipid molecules wrapped around their outer surface. We also demonstrate that insertion of CNTPs into the lipid bilayer results in decreased bilayer thickness with the magnitude of this effect increasing with the concentration of CNTPs. PMID:27322135

  8. α-Synuclein insertion into supported lipid bilayers as seen by in situ X-ray reflectivity.

    PubMed

    Hähl, Hendrik; Möller, Isabelle; Kiesel, Irena; Campioni, Silvia; Riek, Roland; Verdes, Dorinel; Seeger, Stefan

    2015-03-18

    Large aggregates of misfolded α-synuclein inside neuronal cells are the hallmarks of Parkinson's disease. The protein's natural function and its supposed toxicity, however, are believed to be closely related to its interaction with cell and vesicle membranes. Upon this interaction, the protein folds into an α-helical structure and intercalates into the membrane. In this study, we focus on the changes in the lipid bilayer caused by this intrusion. In situ X-ray reflectivity was applied to determine the vertical density structure of the bilayer before and after exposure to α-synuclein. It was found that the α-synuclein insertion, wild type and E57K variant, caused a reduction in bilayer thickness. This effect may be one factor in the membrane pore formation ability of α-synuclein. PMID:25523270

  9. An in situ and operando X-ray absorption spectroscopy setup for measuring sub-monolayer model and powder catalysts.

    PubMed

    Weiher, Norbert; Bus, Eveline; Gorzolnik, Blazej; Möller, Martin; Prins, Roel; van Bokhoven, Jeroen Anton

    2005-09-01

    A new spectroscopic cell has been designed for studying model catalysts using in situ or operando X-ray absorption spectroscopy. The setup allows gas treatment and can be used between 100 and 870 K. Pressures from 10(-3) Pa up to 300 kPa can be applied. Measurements on model systems in this particular pressure range are a valuable extension of the commonly used UHV characterization techniques. Using this setup, we were able to analyze the Au L3 EXAFS of a silica wafer covered with sub-monolayer concentrations of gold (0.05 ML). By modifying the sample holder, powder catalysts can also be analyzed under plug-flow conditions. As an example, the reduction of a Au/SiO2 powder catalyst prepared from HAuCl4 was followed. PMID:16120994

  10. 3D-printed photo-spectroelectrochemical devices for in situ and in operando X-ray absorption spectroscopy investigation.

    PubMed

    Achilli, Elisabetta; Minguzzi, Alessandro; Visibile, Alberto; Locatelli, Cristina; Vertova, Alberto; Naldoni, Alberto; Rondinini, Sandra; Auricchio, Ferdinando; Marconi, Stefania; Fracchia, Martina; Ghigna, Paolo

    2016-03-01

    Three-dimensional printed multi-purpose electrochemical devices for X-ray absorption spectroscopy are presented in this paper. The aim of this work is to show how three-dimensional printing can be a strategy for the creation of electrochemical cells for in situ and in operando experiments by means of synchrotron radiation. As a case study, the description of two cells which have been employed in experiments on photoanodes for photoelectrochemical water splitting are presented. The main advantages of these electrochemical devices are associated with their compactness and with the precision of the three-dimensional printing systems which allows details to be obtained that would otherwise be difficult. Thanks to these systems it was possible to combine synchrotron-based methods with complementary techniques in order to study the mechanism of the photoelectrocatalytic process. PMID:26917152

  11. Mechanisms Determining the Structure of Gold-Catalyzed GaAs Nanowires Studied by in Situ X-ray Diffraction

    DOE PAGESBeta

    Takahasi, Masamitu; Kozu, Miwa; Sasaki, Takuo; Hu, Wen

    2015-09-02

    The evolution of polytypism during GaAs nanowire growth was investigated with in situ X-ray diffraction. The growth of nanowires was found to start with the formation of zincblende structure, followed by the growth of wurtzite structure. The growth process was well reproduced by a simulation based on a layer-by-layer nucleation model. The good agreement between the measured and simulated results confirms that nucleation costs higher energy for the stackings changing the crystal structure than for those conserving the preceding structure. The transition in prevalent structure can be accounted for by the change of local growth conditions related to the shapemore » of triple phase line rather than by the change in supersaturation level, which quickly reaches steady state after starting growth.« less

  12. In-situ early stage electromigration study in Al line using synchrotron polychromatic X-ray microdiffraction

    SciTech Connect

    Chen, Kai; Tamura, Nobumichi; Tu, King-Ning

    2007-10-31

    Electromigration is a phenomenon that has attracted much attention in the semiconductor industry because of its deleterious effects on electronic devices (such as interconnects) as they become smaller and current density passing through them increases. However, the effect of the electric current on the microstructure of interconnect lines during the very early stage of electromigration is not well documented. In the present report, we used synchrotron radiation based polychromatic X-ray microdiffraction for the in-situ study of the electromigration induced plasticity effects on individual grains of an Al (Cu) interconnect test structure. Dislocation slips which are activated by the electric current stressing are analyzed by the shape change of the diffraction peaks. The study shows polygonization of the grains due to the rearrangement of geometrically necessary dislocations (GND) in the direction of the current. Consequences of these findings are discussed.

  13. High-temperature dehydration of talc: a kinetics study using in situ X-ray powder diffraction

    NASA Astrophysics Data System (ADS)

    Wang, Duojun; Yi, Li; Huang, Bojin; Liu, Chuanjiang

    2015-06-01

    High-temperature in situ X-ray powder diffraction patterns were used to study the dehydration kinetics of natural talc with a size of 10-15 µm. The talc was annealed from 1073 to 1223 K, and the variations in the characteristic peaks corresponding to talc with the time were recorded to determine the reaction progress. The decomposition of talc occurred, and peaks corresponding to talc and peaks corresponding to enstatite and quartz were observed. The enstatite and talc exhibited a topotactic relationship. The dehydration kinetics of talc was studied as a function of temperature between 1073 and 1223 K. The kinetics data could be modeled using an Avrami equation that considers nucleation and growth processes ? where n varies from 0.4 to 0.8. The rate constant (k) equation for the natural talc is ? The reaction mechanism for the dehydration of talc is a heterogeneous nucleation and growth mechanism.

  14. In-Situ observation of wet oxidation kinetics on Si (100) via ambient pressure x-ray photoemission spectroscopy

    SciTech Connect

    Hussain, Zahid; Rossi, Massimiliano; Mun, Bongjin S.; Enta, Yoshiharu; Fadley, Charles S.; Lee, Ki-Suk; Kim, Sang-Koog; Shin, Hyun-Joon; Hussain, Zahid; Ross, Jr., Philip N.

    2007-08-24

    The initial stages of wet thermal oxidation of Si(100)-(2x1) have been investigated by in-situ ambient pressure x-ray photoemission spectroscopy (APXPS), including chemical-state resolution via Si 2p core-level spectra. Real-time growth rates of silicon dioxide have been monitored at 100 mTorr of water vapor. This pressure is considerably higher than in any prior study using XPS. Substrate temperatures have been varied between 250 and 500 C. Above a temperature of {approx} 400 C, two distinct regimes, a rapid and a quasi-saturated one, are identified and growth rates show a strong temperature dependence which cannot be explained by the conventional Deal-Grove model.

  15. System for in situ studies of atmospheric corrosion of metal films using soft x-ray spectroscopy and quartz crystal microbalance.

    PubMed

    Forsberg, J; Duda, L-C; Olsson, A; Schmitt, T; Andersson, J; Nordgren, J; Hedberg, J; Leygraf, C; Aastrup, T; Wallinder, D; Guo, J-H

    2007-08-01

    We present a versatile chamber ("atmospheric corrosion cell") for soft x-ray absorption/emission spectroscopy of metal surfaces in a corrosive atmosphere allowing novel in situ electronic structure studies. Synchrotron x rays passing through a thin window separating the corrosion cell interior from a beamline vacuum chamber probe a metal film deposited on a quartz crystal microbalance (QCM) or on the inside of the window. We present some initial results on chloride induced corrosion of iron surfaces in humidified synthetic air. By simultaneous recording of QCM signal and soft x-ray emission from the corroding sample, correlation between mass changes and variations in spectral features is facilitated. PMID:17764316

  16. System for in situ studies of atmospheric corrosion of metal films using soft x-ray spectroscopy and quartz crystal microbalance

    NASA Astrophysics Data System (ADS)

    Forsberg, J.; Duda, L.-C.; Olsson, A.; Schmitt, T.; Andersson, J.; Nordgren, J.; Hedberg, J.; Leygraf, C.; Aastrup, T.; Wallinder, D.; Guo, J.-H.

    2007-08-01

    We present a versatile chamber ("atmospheric corrosion cell") for soft x-ray absorption/emission spectroscopy of metal surfaces in a corrosive atmosphere allowing novel in situ electronic structure studies. Synchrotron x rays passing through a thin window separating the corrosion cell interior from a beamline vacuum chamber probe a metal film deposited on a quartz crystal microbalance (QCM) or on the inside of the window. We present some initial results on chloride induced corrosion of iron surfaces in humidified synthetic air. By simultaneous recording of QCM signal and soft x-ray emission from the corroding sample, correlation between mass changes and variations in spectral features is facilitated.

  17. Synchrotron micro-X-ray fluorescence analysis of natural diamonds: First steps in identification of mineral inclusions in situ

    SciTech Connect

    Sitepu, Husin; Kopylova, Maya G.; Quirt, David H.; Cutler, Jeffrey N.; Kotzer, Thomas G.

    2008-06-09

    Diamond inclusions are of particular research interest in mantle petrology and diamond exploration as they provide direct information about the chemical composition of upper and lower mantle and about the petrogenetic sources of diamonds in a given deposit. The objective of the present work is to develop semi-quantitative analytical tools for non-destructive in situ identification and characterization of mineral inclusions in diamonds using synchrotron micro-X-ray Fluorescence ({mu}SXRF) spectroscopy and micro-X-ray Absorption Near Edge Structure ({mu}XANES) spectroscopy at a focused spot size of 4 to 5 micrometers. The data were collected at the Pacific Northwest Consortium (PNC-CAT) 20-ID microprobe beamline at the Advanced Photon Source, located at the Argonne National Laboratory, and yielded the first high-resolution maps of Ti, Cr, Fe, Ni, Cu, and Zn for natural diamond grains, along with quantitative {mu}SXRF analysis of select chemical elements in exposed kimberlite indicator mineral grains. The distribution of diamond inclusions inside the natural diamond host, both visible and invisible using optical transmitted-light microscopy, can be mapped using synchrotron {mu}XRF analysis. Overall, the relative abundances of chemical elements determined by {mu}SXRF elemental analyses are broadly similar to their expected ratios in the mineral and therefore can be used to identify inclusions in diamonds in situ. Synchrotron {mu}XRF quantitative analysis provides accurate estimates of Cr contents of exposed polished minerals when calibrated using the concentration of Fe as a standard. Corresponding Cr K-edge {mu}XANES analyses on selected inclusions yield unique information regarding the formal oxidation state and local coordination of Cr.

  18. Novel micro-reactor flow cell for investigation of model catalysts using in situ grazing-incidence X-ray scattering.

    PubMed

    Kehres, Jan; Pedersen, Thomas; Masini, Federico; Andreasen, Jens Wenzel; Nielsen, Martin Meedom; Diaz, Ana; Nielsen, Jane Hvolbæk; Hansen, Ole; Chorkendorff, Ib

    2016-03-01

    The design, fabrication and performance of a novel and highly sensitive micro-reactor device for performing in situ grazing-incidence X-ray scattering experiments of model catalyst systems is presented. The design of the reaction chamber, etched in silicon on insulator (SIO), permits grazing-incidence small-angle X-ray scattering (GISAXS) in transmission through 10 µm-thick entrance and exit windows by using micro-focused beams. An additional thinning of the Pyrex glass reactor lid allows simultaneous acquisition of the grazing-incidence wide-angle X-ray scattering (GIWAXS). In situ experiments at synchrotron facilities are performed utilizing the micro-reactor and a designed transportable gas feed and analysis system. The feasibility of simultaneous in situ GISAXS/GIWAXS experiments in the novel micro-reactor flow cell was confirmed with CO oxidation over mass-selected Ru nanoparticles. PMID:26917133

  19. Thermal Expansion of NANOPERM-type Alloys from In-situ X-ray Diffraction

    SciTech Connect

    Bednarcik, J.; Franz, H.; Miglierini, M.; Curfs, C.

    2010-07-13

    NANOPERM-type alloys with nominal compositions of (Fe{sub 1-x}Co{sub x}){sub 76}Mo{sub 8}Cu{sub 1}B{sub 15}(x = 0 and 0.5) were prepared by a single-roller melt-spinning technique. Temperature evolution of the as-quenched ribbons during constant-rate heating (10 degree sign C/min) was continuously followed using a high-energy (88 keV) X-ray diffraction (XRD), performed on the ID11 undulator beamline at the ESRF (Grenoble, France). Moessbauer spectroscopy and XRD confirm an amorphous nature of the melt-spun ribbons. Furthermore, Moessbauer spectroscopy reveals a significant change of magnetic state of the as-quenched precursors when substituting Fe by Co (x 0.5). Analyzing a series of XRD patterns in a reciprocal space yields a thermal expansion of the amorphous alloys providing an insight about the thermally activated effects such as relaxation and crystallization.

  20. In-situ characterization of highly reversible phase transformation by synchrotron X-ray Laue microdiffraction

    NASA Astrophysics Data System (ADS)

    Chen, Xian; Tamura, Nobumichi; MacDowell, Alastair; James, Richard D.

    2016-05-01

    The alloy Cu25Au30Zn45 undergoes a huge first-order phase transformation (6% strain) and shows a high reversibility under thermal cycling and an unusual martensitc microstructure in sharp contrast to its nearby compositions. This alloy was discovered by systematically tuning the composition so that its lattice parameters satisfy the cofactor conditions (i.e., the kinematic conditions of compatibility between phases). It was conjectured that satisfaction of these conditions is responsible for the enhanced reversibility as well as the observed unusual fluid-like microstructure during transformation, but so far, there has been no direct evidence confirming that these observed microstructures are those predicted by the cofactor conditions. To verify this hypothesis, we use synchrotron X-ray Laue microdiffraction to measure the orientations and structural parameters of variants and phases near the austenite/martensite interface. The areas consisting of both austenite and multi-variants of martensite are scanned by microLaue diffraction. The cofactor conditions have been examined from the kinematic relation of lattice vectors across the interface. The continuity condition of the interface is precisely verified from the correspondent lattice vectors between two phases.

  1. Anion exchange in Zn-Al layered double hydroxides: In situ X-ray diffraction study

    NASA Astrophysics Data System (ADS)

    Salak, Andrei N.; Tedim, João; Kuznetsova, Alena I.; Zheludkevich, Mikhail L.; Ferreira, Mário G. S.

    2010-07-01

    Anion exchange capacity is a key factor for the application of Zn-Al layered double hydroxides (LDHs) as nano-containers in active corrosion protection. In this work, the nitrate-pyrovanadate anion exchange/re-exchange processes in these LDHs were investigated in situ. We demonstrate that the exchange reactions lead to a decrease of the average crystallite size of LDHs as a result of mechanical fragmentation of the crystallites rather than dissolution/recrystallization. The fragmentation occurs due to fast anion exchange in the initial stage, and can be controlled by changing the ratio of the available substituent anions to the replacement anions and application of a mechanical activation.

  2. In-situ X-ray absorption spectroscopy analysis of capacity fade in nanoscale-LiCoO{sub 2}

    SciTech Connect

    Patridge, Christopher J.; Swider-Lyons, Karen E.; Twigg, Mark E.; Ramaker, David E.

    2013-07-15

    The local structure of nanoscale (∼10–40 nm) LiCoO{sub 2} is monitored during electrochemical cycling utilizing in-situ X-ray absorption spectroscopy (XAS). The high surface area of the LiCoO{sub 2} nanoparticles not only enhances capacity fade, but also provides a large signal from the particle surface relative to the bulk. Changes in the nanoscale LiCoO{sub 2} metal-oxide bond lengths, structural disorder, and chemical state are tracked during cycling by adapting the delta mu (Δμ) technique in complement with comprehensive extended X-ray absorption fine structure (EXAFS) modeling. For the first time, we use a Δμ EXAFS method, and by comparison of the difference EXAFS spectra, extrapolate significant coordination changes and reduction of cobalt species with cycling. This combined approach suggests Li–Co site exchange at the surface of the nanoscale LiCoO{sub 2} as a likely factor in the capacity fade and irreversible losses in practical, microscale LiCoO{sub 2}. - Graphical abstract: Electrochemical cycling of Li-ion batteries has strong impact on the structure and integrity of the cathode active material particularly near the surface/electrolyte interface. In developing a new method, we have used in-situ X-ray absorption spectroscopy during electrochemical cycling of nanoscale LiCoO{sub 2} to track changes during charge and discharge and between subsequent cycles. Using difference spectra, several small changes in Co-O bond length, Co-O and Co-Co coordination, and site exchange between Co and Li sites can be tracked. These methods show promise as a new technique to better understand processes which lead to capacity fade and loss in Li-ion batteries. - Highlights: • A new method is developed to understand capacity fade in Li-ion battery cathodes. • Structural changes are tracked during Li intercalation/deintercalation of LiCoO{sub 2}. • Surface structural changes are emphasized using nanoscale-LiCoO{sub 2} and difference spectra. • Full multiple

  3. The Effect of Composition and Pressure on the Structure of Carbonate-Silicate Melts Using in situ X-ray Diffuse Scattering

    NASA Astrophysics Data System (ADS)

    Hummer, D. R.; Kavner, A.; Manning, C. E.

    2013-12-01

    Carbonatites are carbon-rich magmas that make up a crucial portion of the deep-Earth carbon cycle. During transport from the site of melting, reaction with surrounding mantle and crust can cause significant changes in their carbonate-silicate ratio. However, very little is known about the structure of carbonate-silicate liquids at the high pressures and temperatures where melts originate and metasomatism occurs. To examine how the melt structure of carbonate-silicate binary systems evolves as a function of pressure and composition, we performed in situ X-ray scattering experiments in the Paris-Edinburgh press at HPCAT (Advanced Photon Source). Mixtures from the CaCO3-CaSiO3 and CaCO3-Mg2SiO4 binary systems were used to simulate mantle carbonatites with differing Si:O ratio. Samples were loaded using the experimental setup of Yamada et al [1], and held at 1800 oC and a pressure of either 3 or 6 GPa while energy dispersive X-ray scattering spectra were recorded. Spectra were collected at nine different scattering angles to achieve coverage in reciprocal space up to q = 20 Å-1. Pair distribution functions for pure calcite confirm that carbonates form a simple ionic liquid, as found by previous investigators. [2,3] The silicate portion of carbonate-silicate melts, however, is extensively chain polymerized. This polymerization occurs even in melts containing Mg2SiO4, in which the solid is completely unpolymerized. However, analysis of Si-Si distances reveals that Mg2SiO4-bearing melts likely contain shorter, more distorted chains, while CaSiO3-bearing melts form extended chains with a Si-O-Si angles close to 180o. For silicate-rich mixtures in both systems, the extent of silica polymerization (as measured by the amount of scattering at the Si-Si pair distance of 3.3 Å) moderately increases with increasing carbonate content. Comparing pair distribution functions calculated from 3 and 6 GPa data reveal that pressure moderately increases the degree of polymerization of

  4. Characterization of beryllium deformation using in-situ x-ray diffraction

    SciTech Connect

    Magnuson, Eric Alan; Brown, Donald William; Clausen, Bjorn; Sisneros, Thomas A.; Park, Jun-Sang

    2015-08-24

    Beryllium’s unique mechanical properties are extremely important in a number of high performance applications. Consequently, accurate models for the mechanical behavior of beryllium are required. However, current models are not sufficiently microstructure aware to accurately predict the performance of beryllium under a range of processing and loading conditions. Previous experiments conducted using the SMARTS and HIPPO instruments at the Lujan Center(LANL), have studied the relationship between strain rate and texture development, but due to the limitations of neutron diffraction studies, it was not possible to measure the response of the material in real-time. In-situ diffraction experiments conducted at the Advanced Photon Source have allowed the real time measurement of the mechanical response of compressed beryllium. Samples of pre-strained beryllium were reloaded orthogonal to their original load path to show the reorientation of already twinned grains. Additionally, the in-situ experiments allowed the real time tracking of twin evolution in beryllium strained at high rates. The data gathered during these experiments will be used in the development and validation of a new, microstructure aware model of the constitutive behavior of beryllium.

  5. Cu isotope fractionation during bornite dissolution: An in situ X-ray diffraction analysis

    SciTech Connect

    Wall, Andrew J.; Mathur, Ryan; Post, Jeffrey E.; Heaney, Peter J.

    2012-10-24

    Low-temperature ore deposits exhibit a large variation in {delta}{sup 65}Cu ({approx}12{per_thousand}), and this range has been attributed, in part, to isotope fractionation during weathering reactions of primary minerals such as chalcocite and chalcopyrite. Here, we examine the fractionation of Cu isotopes during dissolution of another important Cu ore mineral, bornite, using a novel approach that combines time-resolved X-ray diffraction (XRD) and isotope analysis of reaction products. During the initial stages of bornite oxidative dissolution by ferric sulfate (< 5 mol% of total Cu leached), dissolved Cu was enriched in isotopically heavy Cu ({sup 65}Cu) relative to the solid, with an average apparent isotope fractionation ({Delta}{sub aq - min} = {delta}{sup 65}Cu{sub aq} - {delta}{sup 65}Cu{sub min}{sup 0}) of 2.20 {+-} 0.25{per_thousand}. When > 20 mol% Cu was leached from the solid, the difference between the Cu isotope composition of the aqueous and mineral phases approached zero, with {Delta}{sub aq - min}{sup 0} values ranging from - 0.21 {+-} 0.61{per_thousand} to 0.92 {+-} 0.25{per_thousand}. XRD analysis allowed us to correlate changes in the atomic structure of bornite with the apparent isotope fractionation as the dissolution reaction progressed. These data revealed that the greatest degree of apparent fractionation is accompanied by a steep contraction in the unit-cell volume, which we identified as a transition from stoichiometric to non-stoichiometric bornite. We propose that the initially high {Delta}{sub aq - min} values result from isotopically heavy Cu ({sup 65}Cu) concentrating within Cu{sup 2+} during dissolution. The decrease in the apparent isotope fractionation as the reaction progresses occurs from the distillation of isotopically heavy Cu ({sup 65}Cu) during dissolution or kinetic isotope effects associated with the depletion of Cu from the surfaces of bornite particles.

  6. X-ray coherent diffraction imaging of cellulose fibrils in situ.

    PubMed

    Lal, Jyotsana; Harder, Ross; Makowski, Lee

    2011-01-01

    Cellulose is the most abundant renewable source of organic molecules on earth[1]. As fossil fuel reserves become depleted, the use of cellulose as a feed stock for fuels and chemicals is being aggressively explored. Cellulose is a linear polymer of glucose that packs tightly into crystalline fibrils that make up a substantial proportion of plant cell walls. Extraction of the cellulose chains from these fibrils in a chemically benign process has proven to be a substantial challenge [2]. Monitoring the deconstruction of the fibrils in response to physical and chemical treatments would expedite the development of efficient processing methods. As a step towards achieving that goal, we here describe Bragg-coherent diffraction imaging (CDI) as an approach to producing images of cellulose fibrils in situ within vascular bundles from maize. PMID:22254364

  7. In situ X-ray Photoemission Spectroscopy Analysis of Aromatic Polyester Surface Treated with Argon Plasma

    NASA Astrophysics Data System (ADS)

    Narushima, Kazuo; Okamoto, Nanami

    2013-10-01

    Effects of surface modification treatment by argon plasma processing of two types of aromatic polyester, poly(ethylene terephthalate) (PET) and poly(oxybenzonate-co-oxynaphthoate) (POCO), were investigated. This paper presents a description of our experiment and a discussion of the surface modification mechanism, which uses a simple and inexpensive procedure to conduct analysis without breaking vacuum after plasma processing. In situ analysis of the chemical composition of a polymer surface was attempted without exposing the sample to air after argon plasma processing. In particular, the respective actions of each active species were investigated for electrons and ions in argon plasma. Electrons and ions in argon plasma break some polymer bonds. Specifically, ester groups are broken and oxygen atoms are kicked out in PET and POCO. No oxygen functional group is formed after argon plasma processing, but such groups are formed if the sample is exposed to air.

  8. X-ray Coherent Diffraction Imaging of Cellulose Fibrils in Situ

    SciTech Connect

    Lal, Jyotsana; Harder, Ross J.; Makowski, Lee

    2011-01-01

    Cellulose is the most abundant renewable source of organic molecules on earth[1]. As fossil fuel reserves become depleted, the use of cellulose as a feed stock for fuels and chemicals is being aggressively explored. Cellulose is a linear polymer of glucose that packs tightly into crystalline fibrils that make up a substantial proportion of plant cell walls. Extraction of the cellulose chains from these fibrils in a chemically benign process has proven to be a substantial challenge [2]. Monitoring the deconstruction of the fibrils in response to physical and chemical treatments would expedite the development of efficient processing methods. As a step towards achieving that goal, we here describe Bragg-coherent diffraction imaging (CDI) as an approach to producing images of cellulose fibrils in situ within vascular bundles from maize.

  9. Quantitative determination of the oxidation state of iron in biotite using x-ray photoelectron spectroscopy: II. In situ analyses

    SciTech Connect

    Raeburn, S.P. |; Ilton, E.S.; Veblen, D.R.

    1997-11-01

    X-ray photoelectron spectroscopy (XPS) was used to determine Fe(III)/{Sigma}Fe in individual biotite crystals in thin sections of ten metapelites and one syenite. The in situ XPS analyses of Fe(III)/{Sigma}Fe in biotite crystals in the metapelites were compared with published Fe(III)/{Sigma}Fe values determined by Moessbauer spectroscopy (MS) for mineral separates from the same hand samples. The difference between Fe(III)/{Sigma}Fe by the two techniques was greatest for samples with the lowest Fe(III)/{Sigma}Fe (by MS). For eight metamorphic biotites with Fe(III)/{Sigma}Fe = 9-27% comparison of the two techniques yielded a linear correlation of r = 0.94 and a statistically acceptable fit of [Fe(III)/{Sigma}Fe]{sub xps} = [Fe(III)/{Sigma}Fe]{sub ms}. The difference between Fe(III)/{Sigma}Fe by the two techniques was greater for two samples with Fe(III)/{Sigma}Fe {le} 6% (by MS). For biotite in the syenite sample, Fe(III)/{Sigma}Fe determined by both in situ XPS and bulk wet chemistry/electron probe microanalysis were similar. This contribution demonstrates that XPS can be used to analyze bulk Fe(III)/{Sigma}Fe in minerals in thin sections when appropriate precautions taken to avoid oxidation of the near-surface during preparation of samples. 25 refs., 3 figs., 4 tabs.

  10. Monitoring simultaneously the growth of nanoparticles and aggregates by in situ ultra-small-angle x-ray scattering

    NASA Astrophysics Data System (ADS)

    Kammler, Hendrik K.; Beaucage, Gregory; Kohls, Douglas J.; Agashe, Nikhil; Ilavsky, Jan

    2005-03-01

    Ultra-small-angle x-ray scattering can provide information about primary particles and aggregates from a single scattering experiment. This technique is applied in situ to flame aerosol reactors for monitoring simultaneously the primary particle and aggregate growth dynamics of oxide nanoparticles in a flame. This was enabled through the use of a third generation synchrotron source (Advanced Photon Source, Argonne IL, USA) using specialized scattering instrumentation at the UNICAT facility which is capable of simultaneously measuring nanoscales to microscales (1nmto1μm). More specifically, the evolution of primary-particle diameter, mass-fractal dimension, geometric standard deviation, silica volume fraction, number concentration, radius of gyration of the aggregate, and number of primary particles per aggregate are measured along the flame axis for two different premixed flames. All these particle characteristics were derived from a single and nonintrusive measurement technique. Flame temperature profiles were measured in the presence of particles by in situ Fourier transform infrared spectroscopy and thermophoretic sampling was used to visualize particle growth with height above the burner as well as in the radial direction.

  11. Beamline electrostatic levitator for in situ high energy x-ray diffraction studies of levitated solids and liquids

    SciTech Connect

    Gangopadhyay, A.K.; Lee, G.W.; Kelto, K.F.; Rogers, J.R.; Goldman, A.I.; Robinson, D.S.; Rathz, T.J.; Hyers, R.W.

    2010-07-19

    Determinations of the phase formation sequence, crystal structures and the thermo-physical properties of materials at high temperatures are hampered by contamination from the sample container and environment. Containerless processing techniques, such as electrostatic (ESL), electromagnetic, aerodynamic, and acoustic levitation, are most suitable for these studies. An adaptation of ESL for in situ structural studies of a wide range of materials using high energy (30-130 keV) x rays at a synchrotron source is described here. This beamline ESL (BESL) allows the in situ determination of the atomic structures of equilibrium solid and liquid phases, undercooled liquids and time-resolved studies of solid-solid and liquid-solid phase transformations. The use of area detectors enables the rapid acquisition of complete diffraction patterns over a wide range (0.5-14 {angstrom}{sup -1}) of reciprocal space. The wide temperature range (300-2500 K), containerless processing environment under high vacuum (10{sup -7}-10{sup -8} Torr), and fast data acquisition capability, make BESL particularly well suited for phase stability studies of high temperature solids and liquids. An additional, but important, feature of BESL is the capability for simultaneous measurements of a host of thermo-physical properties including the specific heat, enthalpy of transformation, solidus and liquidus temperatures, density, viscosity, and surface tension, all on the same sample during the structural measurements.

  12. In-situ X-ray photoelectron spectroscopy studies of water on metals and oxides at ambient conditions

    SciTech Connect

    Salmeron, Miquel; Yamamoto, S.; Bluhm, H.; Andersson, K.; Ketteler, G.; Ogasawara, H.; Salmeron, M.; Nilsson, A.

    2007-10-29

    X-ray photoelectron spectroscopy (XPS) is a powerful tool for surface and interface analysis, providing the elemental composition of surfaces and the local chemical environment of adsorbed species. Conventional XPS experiments have been limited to ultrahigh vacuum (UHV) conditions due to a short mean free path of electrons in a gas phase. The recent advances in instrumentation coupled with third-generation synchrotron radiation sources enables in-situ XPS measurements at pressures above 5 Torr. In this review, we describe the basic design of the ambient pressure XPS setup that combines differential pumping with an electrostatic focusing. We present examples of the application of in-situ XPS to studies of water adsorption on the surface of metals and oxides including Cu(110), Cu(111), TiO2(110) under environmental conditions of water vapor pressure. On all these surfaces we observe a general trend where hydroxyl groups form first, followed by molecular water adsorption. The importance of surface OH groups and their hydrogen bonding to water molecules in water adsorption on surfaces is discussed in detail.

  13. Colloidal Nanoparticle Interaction Transition during Solvent Evaporation Investigated by in-Situ Small-Angle X-ray Scattering.

    PubMed

    Bahadur, J; Sen, D; Mazumder, S; Santoro, G; Yu, S; Roth, S V; Melnichenko, Y B

    2015-04-28

    In-situ scanning small-angle X-ray scattering (SAXS) experiments have been performed to probe the drying of a single suspended droplet of silica colloids. It has been demonstrated that the formation of a nanoparticle shell during drying can be confirmed just by measuring the temporal evolution of the spatial transmission profile across the drying droplet. The shrinkage of the droplet stops once the shell is formed. The temporal dependence of the shell thickness and droplet radius has been estimated by quantitative analysis of the functionality of the transmission profiles. It is revealed that the position of the correlation peak originating from interactions between silica nanoparticles evolves linearly during the initial stage of drying and exhibits sigmoidal growth behavior in later stages. The interaction between colloidal particles in different drying stages has been investigated. We provide experimental confirmation of the transition from repulsive interaction to a capillary-driven short-range attraction during shell formation. The present work demonstrates that in-situ scanning SAXS on a suspended droplet is an invaluable technique for monitoring the dynamic self-organization of colloids as it probes the drying of complex fluids without the interference of a substrate. PMID:25839830

  14. In situ small-angle X-ray scattering analysis of palladium nanoparticle growth on tobacco mosaic virus nanotemplates.

    PubMed

    Manocchi, Amy K; Seifert, Soenke; Lee, Byeongdu; Yi, Hyunmin

    2011-06-01

    We present an examination of palladium (Pd) nanoparticle growth on genetically modified tobacco mosaic virus (TMV1cys) nanotemplates via in situ small-angle X-ray scattering (SAXS). Specifically, we examine the role of the TMV1cys templates in Pd nanoparticle formation through the electroless reduction of Pd precursor by a chemical reducing agent as compared to identical conditions in the absence of the TMV1cys templates. We show that in the presence of TMV1cys, the viral nanotemplates provide preferential growth sites for Pd nanoparticle formation, as no measurable Pd particle growth was observed in the bulk solution. In situ SAXS confirmed that particle formation was due to the rapid adsorption of Pd atoms onto the TMV1cys templates at the very early stage of mixing, rather than adsorption of particles formed in the bulk solution. Importantly, Pd nanoparticles were significantly smaller and more uniform as compared to particle formation in the absence of TMV1cys. The Pd nanoparticle coating density was tunable based on Pd precursor concentration. Finally, we show that Pd particle growth on the TMV1cys templates was highly rapid, and complete within 33 s for most samples, in contrast to slower Pd particle growth in the absence of TMV templates. We envision that the results presented here will be valuable in furthering the fundamental understanding of the role of viral nanotemplates in particle formation, as well as of their utility in a wide range of applications. PMID:21520923

  15. X-ray Spectrometry.

    ERIC Educational Resources Information Center

    Markowicz, Andrzej A.; Van Grieken, Rene E.

    1984-01-01

    Provided is a selective literature survey of X-ray spectrometry from late 1981 to late 1983. Literature examined focuses on: excitation (photon and electron excitation and particle-induced X-ray emission; detection (wavelength-dispersive and energy-dispersive spectrometry); instrumentation and techniques; and on such quantitative analytical…

  16. When is one layer complete? Using simultaneous in-situ RHEED and x-ray reflectivity to map layer-by-layer thin-film oxide growth

    NASA Astrophysics Data System (ADS)

    Sullivan, M. C.; Ward, M. J.; Joress, H.; Gutierrez-Llorente, A.; White, A. E.; Woll, A.; Brock, J. D.

    2014-03-01

    The most popular tool for characterizing in situ layer-by-layer growth is Reflection High-Energy Electron Diffraction (RHEED). X-ray reflectivity can also be used to study layer-by-layer growth, as long as the incident angle of the x-rays is far from a Bragg peak. During layer-by-layer homoepitaxial growth, both the RHEED intensity and the reflected x-ray intensity will oscillate, and each complete oscillation indicates the addition of one layer of material. However, it is well documented, but not well understood, that the maxima in the RHEED intensity oscillations do not necessarily occur at the completion of a layer. In contrast, the maxima in the x-ray intensity oscillations do occur at the completion of a layer, thus the RHEED and x-ray oscillations are rarely in phase. We present our results on simultaneous in situ x-ray reflectivity and RHEED during layer-by-layer growth of SrTiO3 and discuss how to determine the completion of a layer for RHEED oscillations independent of the phase of the RHEED oscillation. Supported by DOE Office of Basic Energy Sciences Award DE-SC0001086, CHESS is supported by the NSF & NIH/NIGMS via NSF award DMR-0936384.

  17. In situ investigation of working battery electrodes using synchrotron x-ray diffraction

    SciTech Connect

    Jisrawi, N.M.; Thurston, T.R.; Yang, X.Q.

    1996-12-31

    The results of an in situ investigation of the structural changes that occur during the operation of working battery electrodes using synchrotron radiation are presented. Two types of electrodes were investigated: an AB{sub 2}-type Laves phase alloy anode with the composition Zr{sub x}Ti{sub 1-x}M{sub 2} and a proprietary cell based on a Li{sub x}Mn{sub 2}O{sub 4} spinel compound cathode made by Gould electronics. For the Laves phase alloy compositions with x=0.25 and 0.5 and M=V{sub 0.5}N{sub 1.1}Mn{sub 0.2}Fe{sub 0.2} were examined. Cells made from two different batches of Li{sub x}Mn{sub 2}O{sub 4} material were investigated. The relationships between battery performance and structural changes will be discussed. In the later case, we also discuss the role of over-discharging on the Li{sub x}Mn{sub 2}O{sub 4} structure and on battery operation.

  18. In situ x-ray absorption spectroscopy study of tin anode nanomaterials for lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Pelliccione, Christopher J.

    Tin is an attractive alternative to replace traditional carbon based anodes in lithium-ion batteries (LIBs) due to the nearly three-fold increase in theoretical capacity over carbon. However, metallic tin suffers from volumetric expansion of the crystal structure during initial lithium insertion that quickly degrades the material and reduces the performance of the battery. Various techniques have been previously investigated with the goal of suppressing this destructive expansion by incorporating oxygen or a lithium-inactive metal into the tin to provide structural support and mitigate volumetric expansion. These materials show increased capacity retention compared to metallic tin, but still suffer from capacity fading. The nature of these structural degradations must be fully understood to permit engineering of materials that avoid these destructive tendencies and can be considered as viable options for LIBs. In situ X-ray absorption spectroscopy (XAS) measurements were acquired on Sn, SnO2, Sn3O2(OH) 2, Cu6Sn5 and Ni3Sn4 nanoparticle anodes for LIBs. Accompanying the electrochemical characterization conducted on each material, the local atomic structure was modeled as a function of potential during the first charge and also as a function of charged/discharged states for several cycles. The extended X-ray absorption fine structure (EXAFS) theoretical modeling included the first unambiguous observation of Sn-Li coordination numbers and atomic distances in tin-based anode materials. From correlating the electrochemical performance to the EXAFS analysis, the long-term capacity retention of tin-based anodes is dependent on the structural deformations that occur during the first charge. The conversion of oxygen to amorphous Li2O, and the network that it forms, has a dramatic effect on the kinetics of the system and the stability of the local metallic tin structure.

  19. Compact Roll-to-Roll Coater for in Situ X-ray Diffraction Characterization of Organic Electronics Printing.

    PubMed

    Gu, Xiaodan; Reinspach, Julia; Worfolk, Brian J; Diao, Ying; Zhou, Yan; Yan, Hongping; Gu, Kevin; Mannsfeld, Stefan; Toney, Michael F; Bao, Zhenan

    2016-01-27

    We describe a compact roll-to-roll (R2R) coater that is capable of tracking the crystallization process of semiconducting polymers during solution printing using X-ray scattering at synchrotron beamlines. An improved understanding of the morphology evolution during the solution-processing of organic semiconductor materials during R2R coating processes is necessary to bridge the gap between "lab" and "fab". The instrument consists of a vacuum chuck to hold the flexible plastic substrate uniformly flat for grazing incidence X-ray scattering. The time resolution of the drying process that is achievable can be tuned by controlling two independent motor speeds, namely, the speed of the moving flexible substrate and the speed of the printer head moving in the opposite direction. With this novel design, we are able to achieve a wide range of drying time resolutions, from tens of milliseconds to seconds. This allows examination of the crystallization process over either fast or slow drying processes depending on coating conditions. Using regioregular poly(3-hexylthiophene-2,5-diyl) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) inks based on two different solvents as a model system, we demonstrate the capability of our in situ R2R printing tool by observing two distinct crystallization processes for inks drying from the solvents with different boiling points (evaporation rates). We also observed delayed on-set point for the crystallization of P3HT polymer in the 1:1 P3HT/PCBM BHJ blend, and the inhibited crystallization of the P3HT during the late stage of the drying process. PMID:26714412

  20. Fatigue History and in-situ Loading Studies of the overload Effect Using High Resolution X-ray Strain Profiling

    SciTech Connect

    Croft,M.; Jisrawi, N.; Zhong, Z.; Holtz, R.; Sadananda, K.; Skaritka, J.; Tsakalakos, T.

    2007-01-01

    High-energy synchrotron X-ray diffraction experiments are used to perform local crack plane strain profiling of 4140 steel compact tension specimens fatigued at constant amplitude, subjected to a single overload cycle, then fatigued some more at constant amplitude. X-ray strain profiling results on a series of samples employing in-situ load cycling are correlated with the crack growth rate (da/dN) providing insight into the da/dN retardation known as the 'overload effect'. Immediately after the overload, the strain under maximum load is greatly reduced but the range of strain, between zero and maximum load, remains unchanged compared to the pre-overload values. At the point of maximum retardation, it is the strain range that is greatly reduced while the maximum-load strain has begun to recover to the pre-overload value. For a sample that has recovered to approximately half of the original da/dN value following the overload, the strain at maximum load is fully recovered while the strain range, though partially recovered, is still substantially reduced. The dominance of the strain range in the overload effect is clearly indicated. Subject to some assumptions, strong quantitative support for a crack growth rate driving force of the suggested form [(K{sub max}){sup -p}({Delta}K){sup p}]{sup {gamma}} is found. A dramatic nonlinear load dependence in the spatial distribution of the strain at maximum retardation is also demonstrated: at low load the response is dominantly at the overload position; whereas at high loads it is dominantly at the crack tip position. This transfer of load response away from the crack tip to the overload position appears fundamental to the overload effect for high R-ratio fatigue as studied here.

  1. In situ and real-time characterization of metal-organic chemical vapor deposition growth by high resolution x-ray diffraction

    SciTech Connect

    Kharchenko, A.; Lischka, K.; Schmidegg, K.; Sitter, H.; Bethke, J.; Woitok, J.

    2005-03-01

    We present an x-ray diffractometer for the analysis of epitaxial layers during (in situ) metal-organic chemical vapor deposition (MOCVD). Our diffractometer has a conventional x-ray source, does not need a goniometer stage, and is not sensitive to precise adjustment of the samples before measurement. It allows us to perform measurements within a few seconds even from rotating and wobbling samples. The first results of laboratory tests performed with our x-ray diffraction system show that it is well suited for in situ and real-time monitoring of the MOCVD growth process. We were able to measure the growth rate of a cubic GaN layer and the intensity and peak position of Bragg reflections of the growing layer in less than 20 s only.

  2. Mapping strain fields induced in Zr-based bulk metallic glasses during in-situ nanoindentation by X-ray nanodiffraction

    NASA Astrophysics Data System (ADS)

    Gamcová, J.; Mohanty, G.; Michalik, Š.; Wehrs, J.; Bednarčík, J.; Krywka, C.; Breguet, J. M.; Michler, J.; Franz, H.

    2016-01-01

    A pioneer in-situ synchrotron X-ray nanodiffraction approach for characterization and visualization of strain fields induced by nanoindentation in amorphous materials is introduced. In-situ nanoindentation experiments were performed in transmission mode using a monochromatic and highly focused sub-micron X-ray beam on 40 μm thick Zr-based bulk metallic glass under two loading conditions. Spatially resolved X-ray diffraction scans in the deformed volume of Zr-based bulk metallic glass covering an area of 40 × 40 μm2 beneath the pyramidal indenter revealed two-dimensional map of elastic strains. The largest value of compressive elastic strain calculated from diffraction data at 1 N load was -0.65%. The region of high elastic compressive strains (<-0.3%) is located beneath the indenter tip and has radius of 7 μm.

  3. Monitoring of ZnCdSe layer properties by in situ x-ray diffraction during heteroepitaxy on (001)GaAs substrates

    SciTech Connect

    Benkert, A.; Schumacher, C.; Brunner, K.; Neder, R. B.

    2007-04-16

    The authors demonstrate in situ high-resolution x-ray diffraction applied during heteroepitaxy on (001)GaAs for instant layer characterization. The current thickness, composition, strain, and relaxation dynamics of pseudomorphic layers are precisely determined from q{sub z} scans at the (113) reflection measured at a molecular beam epitaxy chamber with a conventional x-ray tube in static geometry. A simple fitting routine enables real-time in situ x-ray diffraction analysis of layers as thin as 20 nm. Critical thicknesses for dislocation formation and plastic relaxation of ZnCdSe layers versus Cd content are determined. The strong influence of substrate temperature on heteroepitaxial nucleation process, deposition rate, composition, and strain relaxation dynamics of ZnCdSe on GaAs is also studied.

  4. An in situ X ray diffraction study of the kinetics of the Ni2SiO4 olivine-spinel transformation

    NASA Technical Reports Server (NTRS)

    Rubie, D. C.; Tsuchida, Y.; Yagi, T.; Utsumi, W.; Kikegawa, T.

    1990-01-01

    The kinetics of the olivine-spinel transformation in Ni2SiO4 were investigated in an in situ X-ray diffraction experiments in which synchrotron radiation was used as an X-ray source. The starting material was Ni2SO4 olivine which was hot-pressed in situ at 980 C and 2.5 GPa; during the transformation, X-ray diffraction patterns were collected at intervals of 30 or 120 sec. The kinetic data were analyzed using Cahn's (1956) model. The activation energy for growth at 3.6-3.7 GPa was estimated as 438 + or - 199 kJ/mol. It is shown that, in order to make significant extrapolations of the kinetic data to a geological scale, the dependence of the rates of both nucleation and growth on temperature and pressure must be evaluated separately.

  5. A CdZnTe array for the detection of explosives in baggage by energy-dispersive X-ray diffraction signatures at multiple scatter angles

    NASA Astrophysics Data System (ADS)

    Malden, Catharine H.; Speller, Robert. D.

    2000-07-01

    CdZnTe detectors were used to collect energy-dispersive diffraction spectra at a range of scatter angles, from sheets of explosives hidden in baggage. It is shown that the combined information from these `signatures' can be used to determine whether an explosive sample is present or not. The geometrical configuration of the collimation and the position of the baggage within the scanner must be taken into careful consideration when optimising the capabilities of such a system. The CdZnTe array lends itself well to the detection of explosives in baggage since multiple signals may be collected simultaneously providing more rapid detection than achieved using a single detector.

  6. Reaction cell for in situ soft x-ray absorption spectroscopy and resonant inelastic x-ray scattering measurements of heterogeneous catalysis up to 1 atm and 250 °C

    SciTech Connect

    Kristiansen, P. T.; Rocha, T. C. R.; Knop-Gericke, A.; Guo, J. H.; Duda, L. C.

    2013-11-15

    We present a novel in situ reaction cell for heterogeneous catalysis monitored in situ by x-ray absorption spectroscopy (XAS) and resonant inelastic x-ray scattering (RIXS). The reaction can be carried out at a total pressure up to 1 atm, a regime that has not been accessible to comparable in situ techniques and thus closes the pressure gap to many industrial standard conditions. Two alternate catalyst geometries were tested: (A) a thin film evaporated directly onto an x-ray transparent membrane with a flowing reaction gas mixture behind it or (B) a powder placed behind both the membrane and a gap of flowing reaction gas mixture. To illustrate the working principle and feasibility of our reaction cell setup we have chosen ethylene epoxidation over a silver catalyst as a test case. The evolution of incorporated oxygen species was monitored by total electron/fluorescence yield O K-XAS as well as O K-RIXS, which is a powerful method to separate contributions from inequivalent sites. We find that our method can reliably detect transient species that exist during catalytic reaction conditions that are hardly accessible using other spectroscopic methods.

  7. In situ X-ray diffraction study of post-spinel transformation in peridotite mantle: Implication to 660 km discontinuity

    NASA Astrophysics Data System (ADS)

    Litasov, K.; Ohtani, E.; Suzuki, A.; Funakoshi, K.

    2004-12-01

    The 660-km seismic discontinuity in the Earth's mantle is identified with the transformation of ringwoodite (spinel (Mg,Fe)2SiO4-phase) to (Mg,Fe)SiO3-perovskite and (Mg,Fe)O-ferropericlase. It was suggested using quench experiments that the transformation boundary has significant negative Clapeyron slope (-3 MPa/K, Ito and Takahashi, 1989) responsible for depressions and elevations of the 660-km discontinuity in subduction zones and hot spots of mantle plumes. Recent in situ x-ray diffraction studies in Mg2SiO4 system indicate that negative slope of the boundary is much gentler (-1.3 MPa/K) (Fei et al., 2004). Therefore there must be another factors resulting in significant depth variations of the 660-km discontinuity. In this study, we present the phase relations in anhydrous pyrolite by in situ X-ray diffraction measurements to examine the influence of additional components and Mg/Si-ratio on post-spinel phase transformation. Experiments were carried out using Speed-1500 multianvil apparatus installed at BL04B1 at synchrotron radiation facility `Spring-8' (Hyogo, Japan). Starting materials were synthetic glass representing SiO2-Al2O3-FeO-MgO-CaO-pyrolite. Graphite capsule were used as a sample container. Co-doped MgO was used as the pressure medium and a cylindrical LaCrO3 heater was used as the heating element. Temperature was measured with a WRe thermocouple. Different equation of states for Au and MgO was used for pressure calibration. The phase relations were determined at 20-25 GPa and temperature up to 2300 K. We observed easy nucleation of Mg-perovskite and ferropericlase from ringwoodite-bearing assembly in the temperature range of 1600-2200 K. The obtained post-spinel phase boundary can be expressed as P (GPa) = - 0.0004 T (K) + 22.26 using pressures calibrated by Au scale (Anderson et al., 1989). The choice of pressure scale does not have significant influence on the slope of phase transformation. Our experiments demonstrated that variations of

  8. Semi-automatic detection of gunshot residue (GSR) by scanning electron microscopy and energy dispersive X-ray analysis (SEM/EDX).

    PubMed

    Gansau, H; Becker, U

    1982-01-01

    Wide strips of adhesive tape (40 mm x 86 mm) are pressed for about one minute on the thumb, forefinger and outer edge of a subject's hand. Subsequently these tapes are fixed to a cylinder that rotates within the SEM chamber and is adjustable in an axial direction. The tapes are scanned for possible GSR particles with simultaneous SE and X-ray imaging. The X-ray signal caused by particles of high atomic number automatically stops the rotating cylinder, and the EDX spectrum of the suspect particle is produced within five seconds. A chart is then plotted to record the size, elemental composition, morphology and tape coordinates of the particles of interest. The outcome is a complete map of GSR particles found on certain parts of the hand, and this map has a characteristic pattern depending on the firearm used, the ammunition and the circumstances of the shooting incident. The time lapse between firing and sampling may allow this GSR pattern to change, but this method is helpful in suicide/homicide decisions. PMID:7167744

  9. Understanding Electrocatalytic Pathways in Low and Medium Temperature Fuel Cells: Synchrotron-based In Situ X-Ray Absorption Spectroscopy

    SciTech Connect

    Mukerjee, S.; Ziegelbauer, J; Arruda, T; Ramaker, D; Shyam, B

    2008-01-01

    Over the last few decades, researchers have made significant developments in producing more advanced electrocatalytic materials for power generation applications. For example, traditional fuel cell catalysts often involve high-priced precious metals such as Pt. However, in order for fuel cells to become commercially viable, there is a need to reduce or completely remove precious metal altogether. As a result, a myriad of novel, unconventional materials have been explored such as chalcogenides, porphyrins, and organic-metal-macrocycles for low/medium temperature fuel cells as well as enzymatic and microbial fuel cells. As these materials increasingly become more complex, researchers often find themselves in search of new characterization methods, especially those which are allow in situ and operando measurements with element specificity. One such method that has received much attention for analysis of electrocatalytic materials is X-ray absorption spectroscopy (XAS). XAS is an element specific, core level absorption technique which yields structural and electronic information. As a core electron method, XAS requires an extremely bright source, hence a synchrotron. The resulting intensity of synchrotron radiation allow for experiments to be conducted in situ, under electrochemically relevant conditions. Although a bulk-averaging technique requiring rigorous mathematical manipulation, XAS has the added benefit that it can probe materials which possess no long range order. This makes it ideal to characterize nano-scale electrocatalysts. XAS experiments are conducted by ramping the X-ray photon energy while measuring absorption of the incident beam the sample or by counting fluorescent photons released from a sample due to subsequent relaxation. Absorption mode XAS follows the Beer-Lambert Law, {mu}x = log(I{sub 0}/I{sub t}) (1) where {mu} is the absorption coefficient, x is the sample thickness and I{sub 0} and I{sub t} are the intensities of the incident and

  10. Development of a new micro-furnace for "in situ" high-temperature single crystal X-ray diffraction measurements

    NASA Astrophysics Data System (ADS)

    Alvaro, Matteo; Angel, Ross J.; Marciano, Claudio; Zaffiro, Gabriele; Scandolo, Lorenzo; Mazzucchelli, Mattia L.; Milani, Sula; Rustioni, Greta; Domeneghetti, Chiara M.; Nestola, Fabrizio

    2015-04-01

    Several experimental methods to reliably determine elastic properties of minerals at non-ambient conditions have been developed. In particular, different techniques for generating high-pressure and high-temperature have been successfully adopted for single-crystal and powder X-ray diffraction measurements. High temperature devices for "in-situ" measurements should provide the most controlled isothermal environment as possible across the entire sample. It is intuitive that in general, thermal gradients across the sample increase as the temperature increases. Even if the small isothermal volume required for single-crystal X-ray diffraction experiments makes such phenomena almost negligible, the design of a furnace should also aim to reduce thermal gradients by including a large thermal mass that encloses the sample. However this solution often leads to complex design that results in a restricted access to reciprocal space or attenuation of the incident or diffracted intensity (with consequent reduction of the accuracy and/or precision in lattice parameter determination). Here we present a newly-developed H-shaped Pt-Pt/Rh resistance microfurnace for in-situ high-temperature single-crystal X-ray diffraction measurements. The compact design of the furnace together with the long collimator-sample-detector distance allows us to perform measurements up to 2θ = 70° with no further restrictions on any other angular movement. The microfurnace is equipped with a water cooling system that allows a constant thermal gradient to be maintained that in turn guarantees thermal stability with oscillations smaller than 5°C in the whole range of operating T of room-T to 1200°C. The furnace has been built for use with a conventional 4-circle Eulerian geometry equipped with point detector and automated with the SINGLE software (Angel and Finger 2011) that allows the effects of crystal offsets and diffractometer aberrations to be eliminated from the refined peak positions by the 8

  11. In situ x-ray diffraction investigations during low energy ion nitriding of austenitic stainless steel grade 1.4571

    NASA Astrophysics Data System (ADS)

    Manova, D.; Mändl, S.; Gerlach, J. W.; Hirsch, D.; Neumann, H.; Rauschenbach, B.

    2014-09-01

    Insertion of nitrogen into austenitic stainless steel leads to anomalously fast nitrogen diffusion and the formation of an expanded face-centred cubic phase which is known to contain a large amount of mechanical stress. In situ x-ray diffraction (XRD) measurements during low energy nitrogen ion implantation into steel 316Ti at 300-550 °C allow a direct view into diffusion and phase formation. While the layer growth is directly observable from the decreasing substrate reflection intensity, the time evolution of the intensities for the expanded phase reflection is much more complex: several mechanisms including at least formation and annealing of defects, twinning, reduction of the crystal symmetry, or grain rotation may be active inside the expanded phase, besides the thermally activated decay of the metastable expanded phase. This locally varying coherence length or scattering intensity from the expanded phase is furthermore a function of temperature and time, additionally complicating the deconvolution of XRD spectra for stress and concentration gradients. As no concise modelling of this coherence length is possible at present, a simple qualitative model assuming a dependence of the scattering intensity on the depth, influence by stress and plastic flow during the nitriding process is proposed for understanding the underlying processes.

  12. In situ X-ray diffraction and the evolution of polarization during the growth of ferroelectric superlattices

    NASA Astrophysics Data System (ADS)

    Bein, Benjamin; Hsing, Hsiang-Chun; Callori, Sara J.; Sinsheimer, John; Chinta, Priya V.; Headrick, Randall L.; Dawber, Matthew

    2015-12-01

    In epitaxially strained ferroelectric thin films and superlattices, the ferroelectric transition temperature can lie above the growth temperature. Ferroelectric polarization and domains should then evolve during the growth of a sample, and electrostatic boundary conditions may play an important role. In this work, ferroelectric domains, surface termination, average lattice parameter and bilayer thickness are simultaneously monitored using in situ synchrotron X-ray diffraction during the growth of BaTiO3/SrTiO3 superlattices on SrTiO3 substrates by off-axis radio frequency magnetron sputtering. The technique used allows for scan times substantially faster than the growth of a single layer of material. Effects of electric boundary conditions are investigated by growing the same superlattice alternatively on SrTiO3 substrates and 20 nm SrRuO3 thin films on SrTiO3 substrates. These experiments provide important insights into the formation and evolution of ferroelectric domains when the sample is ferroelectric during the growth process.

  13. Deciphering the thermal behavior of lithium rich cathode material by in situ X-ray diffraction technique

    NASA Astrophysics Data System (ADS)

    Muhammad, Shoaib; Lee, Sangwoo; Kim, Hyunchul; Yoon, Jeongbae; Jang, Donghyuk; Yoon, Jaegu; Park, Jin-Hwan; Yoon, Won-Sub

    2015-07-01

    Thermal stability is one of the critical requirements for commercial operation of high energy lithium-ion batteries. In this study, we use in situ X-ray diffraction technique to elucidate the thermal degradation mechanism of 0.5Li2MnO3-0.5LiNi0.33Co0.33Mn0.33O2 lithium rich cathode material in the absence and presence of electrolyte to simulate the real life battery conditions and compare its thermal behavior with the commercial LiNi0.33Co0.33Mn0.33O2 cathode material. We show that the thermal induced phase transformations in delithiated lithium rich cathode material are much more intense compared to similar single phase layered cathode material in the presence of electrolyte. The structural changes in both cathode materials with the temperature rise follow different trends in the absence and presence of electrolyte between 25 and 600 °C. Phase transitions are comparatively simple in the absence of electrolyte, the fully charged lithium rich cathode material demonstrates better thermal stability by maintaining its phase till 379 °C, and afterwards spinel structure is formed. In the presence of electrolyte, however, the spinel structure appears at 207 °C, subsequently it transforms to rock salt type cubic phase at 425 °C with additional metallic, metal fluoride, and metal carbonate phases.

  14. Temperature Assisted in-Situ Small Angle X-ray Scattering Analysis of Ph-POSS/PC Polymer Nanocomposite

    PubMed Central

    Yadav, Ramdayal; Naebe, Minoo; Wang, Xungai; Kandasubramanian, Balasubramanian

    2016-01-01

    Inorganic/organic nanofillers have been extensively exploited to impart thermal stability to polymer nanocomposite via various strategies that can endure structural changes when exposed a wide range of thermal environment during their application. In this abstraction, we have utilized temperature assisted in-situ small angle X-ray scattering (SAXS) to examine the structural orientation distribution of inorganic/organic nanofiller octa phenyl substituted polyhedral oligomeric silsesquioxane (Ph-POSS) in Polycarbonate (PC) matrix from ambient temperature to 180 °C. A constant interval of 30 °C with the heating rate of 3 °C/min was utilized to guise the temperature below and above the glass transition temperature of PC followed by thermal gravimetric, HRTEM, FESEM and hydrophobic analysis at ambient temperature. The HRTEM images of Ph-POSS nano unit demonstrated hyperrectangular structure, while FESEM image of the developed nano composite rendered separated phase containing flocculated and overlapped stacking of POSS units in the PC matrix. The phase separation in polymer nanocomposite was further substantiated by thermodynamic interaction parameter (χ) and mixing energy (Emix) gleaned via Accelrys Materials studio. The SAXS spectra has demonstrated duplex peak at higher scattering vector region, postulated as a primary and secondary segregated POSS domain and followed by abundance of secondary peak with temperature augmentation. PMID:27436152

  15. In Situ Neutron and Synchrotron X-ray Diffraction Studies of Jarosite at High-Temperature High-Pressure Conditions

    NASA Astrophysics Data System (ADS)

    Xu, H.; Zhao, Y.; Hickmott, D.; Zhang, J.; Vogel, S.; Daemen, L.; Hartl, M.

    2011-03-01

    Jarosite (KFe 3 (SO4)2 (OH)6) occurs in acid mine drainage and epithermal environments and hot springs associated with volcanic activity. Jarosite is also of industrial interest as an iron-impurity extractor from zinc sulfide ores. In 2004, jarosite was detected by the Mars Exploration Rover Mössbauer spectrometer, which has been interpreted as a strong evidence for the existence of water (and possibly life) on ancient Mars. This discovery has spurred considerable interests in stability and structural behavior of jarosite and related phases at various temperature, pressure, and aqueous conditions. In this work, we have investigated the crystal structure and phase stability of jarosite at temperatures up to 900 K and/or pressures up to 9 GPa using in situ neutron and synchrotron X-ray diffraction. To avoid the large incoherent scattering of neutrons by hydrogen, a deuterated sample was synthesized and characterized. Rietveld analysis of the obtained diffraction data allowed determination of unit-cell parameters, atomic positions and atomic displacement parameters as a function of temperature and pressure. In addition, the coefficients of thermal expansion, bulk moduli and pressure-temperature stability regions of jarosite were determined.

  16. In situ X-ray observations of gas porosity interactions with dendritic microstructures during solidification of Al-based alloys

    NASA Astrophysics Data System (ADS)

    Murphy, A. G.; Browne, D. J.; Houltz, Y.; Mathiesen, R. H.

    2016-03-01

    In situ X-radiography solidification experiments were performed on Al-based alloys, using both synchrotron and laboratory-based X-ray sources, in conjunction with a gradient furnace and a newly developed isothermal furnace, respectively. The effect of gas porosity nucleation and growth within the semi-solid mush during both columnar and equiaxed solidification was thereby observed. In all experimental cases examined, gas porosity was observed to nucleate and grow within the field-of-view (FOV) causing various levels of distortion to the semi-solid mush, and thereafter disappearing from the sample leaving no permanent voids within the solidified microstructure. During columnar growth, a single bubble caused severe remelting and destruction of primary trunks leading to secondary fragmentation and evidence of blocking of the columnar front. Equiaxed solidification was performed under microgravity-like conditions with restricted grain motion in the FOV. The degree to which the nucleated gas bubbles affected the surrounding grain structure increased with increasing solid fraction. However, bubble sphericity remained unaffected by apparent solid fraction or grain coherency.

  17. In situ x-ray scattering study of Ag island growth on Si(111)7 ×7

    NASA Astrophysics Data System (ADS)

    Chen, Yiyao; Gramlich, M. W.; Hayden, S. T.; Miceli, P. F.

    2016-07-01

    We report on the epitaxial relationship between Ag and the Si(111)7 ×7 substrate where the wetting layer and the emergence of islands was investigated using in situ x-ray scattering with a combination of grazing incidence diffraction, specular reflectivity, and crystal truncation rod measurements. The atomic-scale structure of the wetting layer evolves continuously with coverage until a transition where it ceases to change its structure concomitantly with the appearance of islands. The islands are observed to reside on the Si(111)7 ×7 and, although the minimum average island height is three atomic layers of face-centered-cubic Ag, the average island height depends on the coverage and temperature. The majority of the Ag islands are oriented along the symmetry-equivalent Si crystallographic axes and a minority population of islands are rotated by 15 .7∘ . A coincidence-site lattice model is used to show that kinetic considerations lead to the observed island orientations.

  18. In situ X-ray Diffraction Study of Ni–Yb Interlayer and Alloy Systems on Si„100

    SciTech Connect

    Knaepen, W.; Demeulemeester, J; Jordan-Sweet, J; Vantomme, A; Detavernier, C; Van Meirhaeghe, R; Lavoie, C

    2010-01-01

    The phase formation in the ternary Ni/Yb/Si system was studied for Ni-Yb alloy and interlayer structures on Si(100) substrates using in situ x-ray diffraction measurements. Yb was treated as an alloying element in the Ni-Si system with Yb concentrations varying between 0 and 40 at. % of the Ni concentration. Independent of the initial structure of the sample, a Ni-Si or Ni-Yb compound was detected first which suggests that Ni is the dominant diffusing species during the solid state reactions. No pure Yb silicides were identified but a ternary phase (YbNi{sub 2}Si{sub 2}) formed in all samples after the Si atoms became mobile. Information about the distribution of the phases throughout the thin silicide film was obtained using ex situ Rutherford backscattering analysis. Independent of the Yb concentration, the NiSi phase formed at the substrate interface. As a result, the immobile Yb atoms shifted toward the sample surface and no detectable amount of Yb atoms was left at the Ni-silicide/Si interface after annealing.

  19. Dissolution dynamics of the calcite-water interface observed in situ by glancing-incidence X-ray scattering

    SciTech Connect

    Sturchio, N.C.; Chiarello, R.P.

    1995-06-02

    Glancing-incidence X-ray scattering measurements made at the National Synchrotron Light Source were used to investigate dissolution dynamics in situ at the calcite-water interface. The relation between calcite saturation state and roughness of the calcite (1014) cleavage surface as a function of time was examined during pH titrations of an initially calcite-saturated solution. Systematic variations in roughness were observed as a function of saturation state as pH was titrated to values below that of calcite saturation. Different steady-state values of roughness were evident at fixed values of {Delta}G{sub r}, and these were correlated with the extent of undersaturation. A significant increase in roughness begins to occur with increasing undersaturation at a {Delta}G{sub r} value of approximately {minus}2.0 kcal/mol. The dissolution rate corresponding to this increase is about 1.5 x 10{sup 7} mmol/cm {center_dot} sec. This increase in roughness is attributed to a transition in the principal rate-determining dissolution mechanism, and is consistent with both powder-reaction studies of dissolution kinetics and single-crystal dissolution studies by atomic force microscopy. These data indicate some important potential applications of GIXS in the study of mineral-water interface geochemistry.

  20. In-situ Surface X-ray Diffraction Study of Ruddlesden-Popper Series Thin Film Growth

    NASA Astrophysics Data System (ADS)

    Lee, June Hyuk; Chang, Seo Hyoung; Luo, Zhenlin; Tung, I.-Cheng; Malshe, Milind; Jellinek, Julius; Eastman, Jeff; Hong, Hawoong; Fong, Dillon; John, Freeland

    2013-03-01

    The layered Ruddlesden-Popper phases of An+1BnO3n+1, such as Sr2TiO4 and La2NiO4, have attracted much attention as potential materials for solid-oxide fuel cell cathodes and thermoelectrics. To understand the fundamentals of this class of layered oxide thin films, we studied the growth of (001)-oriented Sr2TiO4 and La2NiO4 on SrTiO3 substrates by using oxide molecular beam epitaxy with in-situ surface x-ray diffraction. For Sr2TiO4, the synthesis of the double SrO layer followed by TiO2 dynamically reconstructs back into the SrTiO3 phase, which demonstrates that during thin film deposition other pathways under growth conditions can give rise to new structural arrangements. In contrast with Sr2TiO4, the growth of La2NiO4 involves the stacking of polar LaO+ and NiO2-layers. This raises the question of how polarity mismatch at the interface with the SrTiO3 substrate will influence the growth process. A detail comparison of these two cases will be discussed. Work at the Advanced Photon Source, Argonne is supported by the U.S. Department of Energy, Office of Science, and Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.

  1. In situ x-ray scattering study of a main-chain thermotropic liquid crystalline polymer under oscillatory shear flow

    NASA Astrophysics Data System (ADS)

    Vaish, Nitin; Burghardt, Wesley R.; Zhou, Weijun; Kornfield, Julia A.

    2000-03-01

    Liquid crystalline polymers (LCPs) have been the subject of extensive studies because of potential commercial applications and scientific challenges. The excellent mechanical properties of LCPs arise from highly anisotropic molecular structure, which develops as a complex interplay between molecular dynamics and the applied flow field. We study the behavior of model thermotropic main-chain LCP (DHMS-7,9) under oscillatory shear flow using in situ X-ray scattering techniques. Experiments were done in nematic (140^o C) and x-phase (110^o C) to study the effects of frequency (0.5 - 50 rps) and strain amplitude (50 200In nematic phase, strong alignment in the flow direction (‘parallel’) was observed. The steady state was reached quickly either at high strain amplitudes or high frequencies. In x-phase, molecules aligned in flow direction at high strain levels or oscillation frequency, while alignment in vorticity (‘perpendicular’) direction was observed at low strain amplitude or frequency. In addition, we present the flipping of orientation from parallel to perpendicular alignment as a result of step change in temperature from 140^o C to 110^o C and oscillatory motion from a pre-aligned parallel state in x-phase.

  2. Measurement of Sn and In Solidification Undercooling and Lattice Expansion Using in situ x-ray diffraction

    SciTech Connect

    Elmer, J. W.; Specht, Eliot D

    2011-01-01

    Undercooling of low melting point metals, Sn and In, on graphite, Cu, and Au-coated Cu surfaces is examined using an in-situ x-ray diffraction technique. Undercoolings of up to 56.1 C were observed for Sn solidified on graphite, which is a non-wetting substrate, while lower undercoolings were observed for Sn of 17.3 C on Au/Ni/Cu and 10.5 C on Cu surfaces. Indium behaved quite differently, showing undercoolings of less than 4 C on all three substrates. In addition, lattice expansion/contraction behavior of Sn, In and intermetallic compounds (IMCs) that formed during the reaction of Sn with the Au/Ni/Cu surface were measured. Results showed anisotropic and non-linear expansion of both Sn and In, with a contraction, rather than expansion, of the basal planes of In during heating. The principal IMC that formed between Sn and the Au/Ni/Cu surface was characterized as CuSn and had an average expansion coefficient of 13.6x10-6/ C, which is less than that of Sn or Cu.

  3. In situ X-ray diffraction and the evolution of polarization during the growth of ferroelectric superlattices.

    PubMed

    Bein, Benjamin; Hsing, Hsiang-Chun; Callori, Sara J; Sinsheimer, John; Chinta, Priya V; Headrick, Randall L; Dawber, Matthew

    2015-01-01

    In epitaxially strained ferroelectric thin films and superlattices, the ferroelectric transition temperature can lie above the growth temperature. Ferroelectric polarization and domains should then evolve during the growth of a sample, and electrostatic boundary conditions may play an important role. In this work, ferroelectric domains, surface termination, average lattice parameter and bilayer thickness are simultaneously monitored using in situ synchrotron X-ray diffraction during the growth of BaTiO3/SrTiO3 superlattices on SrTiO3 substrates by off-axis radio frequency magnetron sputtering. The technique used allows for scan times substantially faster than the growth of a single layer of material. Effects of electric boundary conditions are investigated by growing the same superlattice alternatively on SrTiO3 substrates and 20 nm SrRuO3 thin films on SrTiO3 substrates. These experiments provide important insights into the formation and evolution of ferroelectric domains when the sample is ferroelectric during the growth process. PMID:26634894

  4. In situ X-ray diffraction and the evolution of polarization during the growth of ferroelectric superlattices

    SciTech Connect

    Bein, Benjamin; Hsing, Hsiang-Chun; Callori, Sara J.; Sinsheimer, John; Chinta, Priya V.; Headrick, Randall L.; Dawber, Matthew

    2015-12-04

    In the epitaxially strained ferroelectric thin films and superlattices, the ferroelectric transition temperature can lie above the growth temperature. Ferroelectric polarization and domains should then evolve during the growth of a sample, and electrostatic boundary conditions may play an important role. In this work, ferroelectric domains, surface termination, average lattice parameter and bilayer thickness are simultaneously monitored using in situ synchrotron X-ray diffraction during the growth of BaTiO3/SrTiO3 superlattices on SrTiO3 substrates by off-axis radio frequency magnetron sputtering. The technique used allows for scan times substantially faster than the growth of a single layer of material. Effects of electric boundary conditions are investigated by growing the same superlattice alternatively on SrTiO3 substrates and 20 nm SrRuO3 thin films on SrTiO3 substrates. Our experiments provide important insights into the formation and evolution of ferroelectric domains when the sample is ferroelectric during the growth process.

  5. In situ X-ray diffraction and the evolution of polarization during the growth of ferroelectric superlattices

    PubMed Central

    Bein, Benjamin; Hsing, Hsiang-Chun; Callori, Sara J.; Sinsheimer, John; Chinta, Priya V.; Headrick, Randall L.; Dawber, Matthew

    2015-01-01

    In epitaxially strained ferroelectric thin films and superlattices, the ferroelectric transition temperature can lie above the growth temperature. Ferroelectric polarization and domains should then evolve during the growth of a sample, and electrostatic boundary conditions may play an important role. In this work, ferroelectric domains, surface termination, average lattice parameter and bilayer thickness are simultaneously monitored using in situ synchrotron X-ray diffraction during the growth of BaTiO3/SrTiO3 superlattices on SrTiO3 substrates by off-axis radio frequency magnetron sputtering. The technique used allows for scan times substantially faster than the growth of a single layer of material. Effects of electric boundary conditions are investigated by growing the same superlattice alternatively on SrTiO3 substrates and 20 nm SrRuO3 thin films on SrTiO3 substrates. These experiments provide important insights into the formation and evolution of ferroelectric domains when the sample is ferroelectric during the growth process. PMID:26634894

  6. Versatile plug flow catalytic cell for in situ transmission/fluorescence x-ray absorption fine structure measurements

    SciTech Connect

    Centomo, P.; Zecca, M.; Meneghini, C.

    2013-05-15

    A novel flow-through catalytic cell has been developed for in situ x-ray absorption spectroscopy (XAS) experiments on heterogeneous catalysts under working conditions and in the presence of a liquid and a gas phase. The apparatus allows to carry out XAS measurements in both the transmission and fluorescence modes, at moderate temperature (from RT to 50-80 Degree-Sign C) and low-medium gas pressure (up to 7-8 bars). The materials employed are compatible with several chemicals such as those involved in the direct synthesis of hydrogen peroxide (O{sub 2}, H{sub 2}, H{sub 2}O{sub 2}, methanol). The versatile design of the cell allows to fit it to different experimental setups in synchrotron radiation beamlines. It was used successfully for the first time to test nanostructured Pd catalysts during the direct synthesis of hydrogen peroxide (H{sub 2}O{sub 2}) in methanol solution from dihydrogen and dioxygen.

  7. In situ x-ray scattering study of the passive film on Ni(III) in sulfuric acid solution

    SciTech Connect

    Magnussen, O.M.; Scherer, J.; Ocko, B.M.; Behm, R.J.

    2000-02-17

    Results of an in situ X-ray scattering study of the passive film formed on Ni(111) electrodes by passivation in 0.05 M H{sub 2}SO{sub 4} (pH 1.0) at 0.50 V{sub Ag/AgCl} are reported and compared with results on the film formed by oxidation in air at room temperature. In both cases, ultrathin, (111)-oriented NiO films are observed, which are aligned with the Ni substrate lattice and slightly expanded along the surface normal with respect to bulk NiO. However, two major structural differences are found: (1) while on the air-formed oxide parallel (NiO-[1{bar 1}0] {parallel} Ni[1{bar 1}0]) and antiparallel (NiO[1{bar 1}0] {parallel} Ni[{bar 1}10]) oriented domains coexist, the passive film exhibits a well-defined antiparallel orientation and (2) the lattice of the passive film is, in contrast to that of the air-formed oxide, tilted relative to the substrate with a broad angular dispersion of the tilt angle centered at about 3.3{degree}.

  8. In-situ X-ray diffraction and STM studies of bromide adsorption on Au(111) electrodes

    SciTech Connect

    Magnussen, O.M.; Ocko, B.M; Wang, J.X.; Adzic, R.R.

    1996-03-28

    The structure of bromide adlayers at the Au(111)-aqueous solution interface has been studied by in-situ surface X-ray scattering (SXS) and scanning tunneling microscopy (STM). Both techniques show the existence of a hexagonal close-packed adlayer phase above a critical potential and are in good quantitative agreement on the adlayer structural parameters. The bromide-bromide spacing changes continuously between 4.24 A at the critical potential and 4.03 A at a potential 300 mV more positive. The adlayer is rotated relative to the substrate by an angle dependent on potential and bromide concentration. The potential- dependent adlayer density corresponding to these structural results agrees well with Br surface excess densities from published electrochemical measurements. At very positive potentials a bromide-induced step-flow etching of the Au substrate is observed. The results are used to compare the different techniques and to discuss the adlayer structure, the phase behavior, and the halide-gold chemical interaction. 49 refs., 8 figs.

  9. Pressure-induced phase transitions in rubidium azide: Studied by in-situ x-ray diffraction

    SciTech Connect

    Li, Dongmei; Wu, Xiaoxin; Jiang, Junru; Zhang, Jian; Cui, Qiliang; Zhu, Hongyang; Wang, Xiaoli

    2014-08-18

    We present the in-situ X-ray diffraction studies of RbN{sub 3} up to 42.0 GPa at room temperature to supplement the high pressure exploration of alkali azides. Two pressure-induced phase transitions of α-RbN{sub 3} → γ-RbN{sub 3} → δ-RbN{sub 3} were revealed at 6.5 and 16.0 GPa, respectively. During the phase transition of α-RbN{sub 3} → γ-RbN{sub 3}, lattice symmetry decreases from a fourfold to a twofold axis accompanied by a rearrangement of azide anions. The γ-RbN{sub 3} was identified to be a monoclinic structure with C2/m space group. Upon further compression, an orthogonal arrangement of azide anions becomes energetically favorable for δ-RbN{sub 3}. The compressibility of α-RbN{sub 3} is anisotropic due to the orientation of azide anions. The bulk modulus of α-RbN{sub 3} is 18.4 GPa, quite close to those of KN{sub 3} and CsN{sub 3}. By comparing the phase transition pressures of alkali azides, their ionic character is found to play a key role in pressure-induced phase transitions.

  10. Crystal structure of a high-pressure/high-temperature phase of alumina by in situ X-ray diffraction.

    PubMed

    Lin, Jung-Fu; Degtyareva, Olga; Prewitt, Charles T; Dera, Przemyslaw; Sata, Nagayoshi; Gregoryanz, Eugene; Mao, Ho-Kwang; Hemley, Russell J

    2004-06-01

    Alumina (alpha-Al(2)O(3)) has been widely used as a pressure calibrant in static high-pressure experiments and as a window material in dynamic shock-wave experiments; it is also a model material in ceramic science. So understanding its high-pressure stability and physical properties is crucial for interpreting such experimental data, and for testing theoretical calculations. Here we report an in situ X-ray diffraction study of alumina (doped with Cr(3+)) up to 136 GPa and 2,350 K. We observe a phase transformation that occurs above 96 GPa and at high temperatures. Rietveld full-profile refinements show that the high-pressure phase has the Rh(2)O(3) (II) (Pbcn) structure, consistent with theoretical predictions. This phase is structurally related to corundum, but the AlO(6) polyhedra are highly distorted, with the interatomic bond lengths ranging from 1.690 to 1.847 A at 113 GPa. Ruby luminescence spectra from Cr(3+) impurities within the quenched samples under ambient conditions show significant red shifts and broadening, consistent with the different local environments of chromium atoms in the high-pressure structure inferred from diffraction. Our results suggest that the ruby pressure scale needs to be re-examined in the high-pressure phase, and that shock-wave experiments using sapphire windows need to be re-evaluated. PMID:15146173

  11. In situ synchrotron X-ray diffraction analysis of deformation behaviour in Ti-Ni-based thin films.

    PubMed

    Wang, Hong; Sun, Guangai; Wang, Xiaolin; Chen, Bo; Zu, Xiaotao; Liu, Yanping; Li, Liangbin; Pan, Guoqiang; Sheng, Liusi; Liu, Yaoguang; Fu, Yong Qing

    2015-01-01

    Deformation mechanisms of as-deposited and post-annealed Ti50.2Ni49.6, Ti50.3Ni46.2Cu3.5 and Ti48.5Ni40.8Cu7.5 thin films were investigated using the in situ synchrotron X-ray diffraction technique. Results showed that initial crystalline phases determined the deformation mechanisms of all the films during tensile loading. For the films dominated by monoclinic martensites (B19'), tensile stress induced the detwinning of 〈011〉 type-II twins and resulted in the preferred orientations of (002)B19' parallel to the loading direction (∥ LD) and (020)B19' perpendicular to the LD (⊥ LD). For the films dominated by austenite (B2), the austenite directly transformed into martensitic variants (B19') with preferred orientations of (002)B19' ∥ LD and (020)B19' ⊥ LD. For the Ti50.3Ni46.2Cu3.5 and Ti48.1Ni40.8Cu7.5 films, martensitic transformation temperatures decreased apparently after post-annealing because of the large thermal stress generated in the films due to the large differences in thermal expansion coefficients between the film and substrate. PMID:25537586

  12. In situ X-ray diffraction and the evolution of polarization during the growth of ferroelectric superlattices

    DOE PAGESBeta

    Bein, Benjamin; Hsing, Hsiang-Chun; Callori, Sara J.; Sinsheimer, John; Chinta, Priya V.; Headrick, Randall L.; Dawber, Matthew

    2015-12-04

    In the epitaxially strained ferroelectric thin films and superlattices, the ferroelectric transition temperature can lie above the growth temperature. Ferroelectric polarization and domains should then evolve during the growth of a sample, and electrostatic boundary conditions may play an important role. In this work, ferroelectric domains, surface termination, average lattice parameter and bilayer thickness are simultaneously monitored using in situ synchrotron X-ray diffraction during the growth of BaTiO3/SrTiO3 superlattices on SrTiO3 substrates by off-axis radio frequency magnetron sputtering. The technique used allows for scan times substantially faster than the growth of a single layer of material. Effects of electric boundarymore » conditions are investigated by growing the same superlattice alternatively on SrTiO3 substrates and 20 nm SrRuO3 thin films on SrTiO3 substrates. Our experiments provide important insights into the formation and evolution of ferroelectric domains when the sample is ferroelectric during the growth process.« less

  13. Temperature Assisted in-Situ Small Angle X-ray Scattering Analysis of Ph-POSS/PC Polymer Nanocomposite

    NASA Astrophysics Data System (ADS)

    Yadav, Ramdayal; Naebe, Minoo; Wang, Xungai; Kandasubramanian, Balasubramanian

    2016-07-01

    Inorganic/organic nanofillers have been extensively exploited to impart thermal stability to polymer nanocomposite via various strategies that can endure structural changes when exposed a wide range of thermal environment during their application. In this abstraction, we have utilized temperature assisted in-situ small angle X-ray scattering (SAXS) to examine the structural orientation distribution of inorganic/organic nanofiller octa phenyl substituted polyhedral oligomeric silsesquioxane (Ph-POSS) in Polycarbonate (PC) matrix from ambient temperature to 180 °C. A constant interval of 30 °C with the heating rate of 3 °C/min was utilized to guise the temperature below and above the glass transition temperature of PC followed by thermal gravimetric, HRTEM, FESEM and hydrophobic analysis at ambient temperature. The HRTEM images of Ph-POSS nano unit demonstrated hyperrectangular structure, while FESEM image of the developed nano composite rendered separated phase containing flocculated and overlapped stacking of POSS units in the PC matrix. The phase separation in polymer nanocomposite was further substantiated by thermodynamic interaction parameter (χ) and mixing energy (Emix) gleaned via Accelrys Materials studio. The SAXS spectra has demonstrated duplex peak at higher scattering vector region, postulated as a primary and secondary segregated POSS domain and followed by abundance of secondary peak with temperature augmentation.

  14. Temperature Assisted in-Situ Small Angle X-ray Scattering Analysis of Ph-POSS/PC Polymer Nanocomposite.

    PubMed

    Yadav, Ramdayal; Naebe, Minoo; Wang, Xungai; Kandasubramanian, Balasubramanian

    2016-01-01

    Inorganic/organic nanofillers have been extensively exploited to impart thermal stability to polymer nanocomposite via various strategies that can endure structural changes when exposed a wide range of thermal environment during their application. In this abstraction, we have utilized temperature assisted in-situ small angle X-ray scattering (SAXS) to examine the structural orientation distribution of inorganic/organic nanofiller octa phenyl substituted polyhedral oligomeric silsesquioxane (Ph-POSS) in Polycarbonate (PC) matrix from ambient temperature to 180 °C. A constant interval of 30 °C with the heating rate of 3 °C/min was utilized to guise the temperature below and above the glass transition temperature of PC followed by thermal gravimetric, HRTEM, FESEM and hydrophobic analysis at ambient temperature. The HRTEM images of Ph-POSS nano unit demonstrated hyperrectangular structure, while FESEM image of the developed nano composite rendered separated phase containing flocculated and overlapped stacking of POSS units in the PC matrix. The phase separation in polymer nanocomposite was further substantiated by thermodynamic interaction parameter (χ) and mixing energy (Emix) gleaned via Accelrys Materials studio. The SAXS spectra has demonstrated duplex peak at higher scattering vector region, postulated as a primary and secondary segregated POSS domain and followed by abundance of secondary peak with temperature augmentation. PMID:27436152

  15. Direct Observations of Rapid Diffusion of Cu in Au Thin Films Using In-Situ X-Ray Diffraction

    SciTech Connect

    Elmer, J. W.; Palmer, T. A.; Specht, Eliot D

    2006-01-01

    In situ x-ray diffraction was performed while annealing thin film Au/Cu binary diffusion couples to directly observe diffusion at elevated temperatures. The temperature dependence of the interdiffusion coefficient was determined from isothermal measurements at 700, 800, and 900 C, where Cu and Au form a disordered continuous face centered cubic solid solution. Large differences in the lattice parameters of Au and Cu allowed the initial diffraction peaks to be easily identified, and later tracked as they merged into one diffraction peak with increased diffusion time. Initial diffusion kinetics were studied by measuring the time required for the Cu to diffuse through the Au thin film of known thickness. The activation energy for interdiffusion was measured to be 65.4 kJ/mole during this initial stage, which is approximately 0.4x that for bulk diffusion and 0.8x that for grain boundary diffusion. The low activation energy is attributed to the high density of columnar grain boundaries combined with other defects in the sputter deposited thin film coatings. As interdiffusion continues, the two layers homogenize with an activation energy of 111 kJ/mole during the latter stages of diffusion. This higher activation energy falls between the reported values for grain boundary and bulk diffusion, and may be related to grain growth occurring at these temperatures which accounts for the decreasing importance of grain boundaries on diffusion.

  16. Determination of GaN solubility in supercritical ammonia with NH4F and NH4Cl mineralizer by in situ x-ray imaging of crystal dissolution

    NASA Astrophysics Data System (ADS)

    Schimmel, Saskia; Lindner, Michael; Steigerwald, Thomas G.; Hertweck, Benjamin; Richter, Theresia M. M.; Künecke, Ulrike; Alt, Nicolas S. A.; Niewa, Rainer; Schlücker, Eberhard; Wellmann, Peter J.

    2015-05-01

    Quantitative data on the solubility of GaN in supercritical ammonia using NH4F as mineralizer are reported. The solubility is determined by in situ x-ray imaging of the dissolution of GaN single crystals. First, solubility values obtained by this method with NH4Cl as mineralizer are presented and discussed with respect to existing literature data. Monitoring the dissolution process in situ reveals the time when the solubility limit is reached. Thus, it allows to distinguish the saturation of the solution from dissolution based on mass transport and deposition. This is a key advantage of solubility measurements by in situ x-ray imaging compared to gravimetric methods. Our results indicate that the solubility limit is reached much faster than usually assumed in gravimetric solubility studies and the solubility of GaN in ammonothermal media is significantly lower than reported so far.

  17. Effect of Cl{sub 2}- and HBr-based inductively coupled plasma etching on InP surface composition analyzed using in situ x-ray photoelectron spectroscopy

    SciTech Connect

    Bouchoule, S.; Vallier, L.; Patriarche, G.; Chevolleau, T.; Cardinaud, C.

    2012-05-15

    A Cl{sub 2}-HBr-O{sub 2}/Ar inductively coupled plasma (ICP) etching process has been adapted for the processing of InP-based heterostructures in a 300-mm diameter CMOS etching tool. Smooth and anisotropic InP etching is obtained at moderate etch rate ({approx}600 nm/min). Ex situ x-ray energy dispersive analysis of the etched sidewalls shows that the etching anisotropy is obtained through a SiO{sub x} passivation mechanism. The stoichiometry of the etched surface is analyzed in situ using angle-resolved x-ray photoelectron spectroscopy. It is observed that Cl{sub 2}-based ICP etching results in a significantly P-rich surface. The phosphorous layer identified on the top surface is estimated to be {approx}1-1.3-nm thick. On the other hand InP etching in HBr/Ar plasma results in a more stoichiometric surface. In contrast to the etched sidewalls, the etched surface is free from oxides with negligible traces of silicon. Exposure to ambient air of the samples submitted to Cl{sub 2}-based chemistry results in the complete oxidation of the P-rich top layer. It is concluded that a post-etch treatment or a pure HBr plasma step may be necessary after Cl{sub 2}-based ICP etching for the recovery of the InP material.

  18. The identification of the pigments used to paint statues of Feixiange Cliff in China in late 19th century by micro-Raman spectroscopy and scanning electron microscopy/energy dispersive X-ray analysis

    NASA Astrophysics Data System (ADS)

    Jin, Pu-jun; Huang, Wei; Jianhua-Wang; Zhao, Gang; Wang, Xiao-ling

    2010-11-01

    The application of micro-Raman spectroscopy (μ-RS) and scanning electron microscopy (SEM)/energy dispersive X-ray spectrometer (EDS) to the research of pigments collected from Statues of Feixiange Cliff No. 67 and No. 69 niche of Tang Dynasty in China is reported. Five kinds of pigments were found in the experimental data, including black (carbon), white (gypsum + quartz), blue (lapis lazuli) and green (Paris green + Barium sulphate). After synthesized in 1814, Paris green was reported for a large import as a light and bright green pigment to paint architectures in China from the late 19th century. The analyzed blue pigment demonstrated the similar Raman spectra to the Lâjvardina blue glazed ceramics, which indicated lapis lazuli was an artificial product. This confirmed the painting of Feixiange Cliff in the early Republic of China as the historical record, and also reveals that some pigments were imported from abroad.

  19. Electron-excited energy dispersive x-ray spectrometry in the variable pressure scanning electron microscope (EDS/VPSEM): it's not microanalysis anymore!

    NASA Astrophysics Data System (ADS)

    Newbury, Dale E.; Ritchie, Nicholas W. M.

    2015-10-01

    X-ray spectra suffer significantly degraded spatial resolution when measured in the variable-pressure scanning electron microscope (VPSEM, chamber pressure 1 Pa to 2500 Pa) as compared to highvacuum SEM (operating pressure < 10 mPa). Depending on the gas path length, electrons that are scattered hundreds of micrometers outside the focused beam can contribute 90% or more of the measured spectrum. Monte Carlo electron trajectory simulation, available in NIST DTSA-II, models the gas scattering and simulates mixed composition targets, e.g., particle on substrate. The impact of gas scattering at the major (C > 0.1 mass fraction), minor (0.01 <= C <= 0.1), and trace (C < 0.01) constituent levels can be estimated. NIST DTSA-II for Java-platforms is available free at: http://www.cstl.nist.gov/div837/837.02/epq/dtsa2/index.html).

  20. X ray attenuation measurements for high-temperature materials characterization and in-situ monitoring of damage accumulation. Ph.D. Thesis - Cleveland State Univ., 1991

    NASA Technical Reports Server (NTRS)

    Baaklini, George Y.

    1992-01-01

    The scope of this dissertation is to develop and apply x ray attenuation measurement systems that are capable of: (1) characterizing density variations in high-temperature materials, e.g., monolithic ceramics, ceramic and intermetallic matrix composites, and (2) noninvasively monitoring damage accumulation and failure sequences in ceramic matrix composites under room temperature tensile testing. This dissertation results in the development of: (1) a point scan digital radiography system, and (2) an in-situ x ray material testing system. Radiographic evaluation before, during, and after loading shows the effect of preexisting volume flaws on the fracture behavior of composites. Results show that x ray film radiography can monitor damage accumulation during tensile loading. Matrix cracking, fiber matrix debonding, fiber bridging, and fiber pullout are imaged throughout the tensile loading of the specimens. Further in-situ radiography is found to be a practical technique for estimating interfacial shear strength between the silicon carbide fibers and the reaction bonded silicon nitride matrix. It is concluded that pretest, in-situ, and post test x ray imaging can provide for greater understanding of ceramic matrix composite mechanical behavior.

  1. Solubility of Minerals in HP-HT Aqueous Fluids: Results and Potentials of in situ Synchrotron X-Ray Fluorescence

    NASA Astrophysics Data System (ADS)

    Daniel, I.; Sanchez Valle, C.; Reynard, B.; Martinez, I.; Simionovici, A. S.

    2005-12-01

    CO2-rich saline aqueous fluids are liberated into the mantle when the altered oceanic crust is subducted, leading to the important geochemical phenomena of mantle wedge metasomatism and arc magmatism. To better understand these processes, knowledge of mineral-fluid equilibria and mineral solubility in high pressure-high temperature crustal fluids is thus required. We report here in situ measurements on the solubility of strontianite (SrCO3) and GeO2-rutile at P (up to 6.6 GPa) and T (up to 400°C) relevant for cold subducted slabs. The composition of the fluid surrounding the crystal, loaded in an externally heated diamond-anvil cell, was analysed in situ by monitoring the X-ray fluorescence of Sr2+ and Ge4+ cations, respectively, until chemical equilibrium was reached. Experiments were carried out at the ESRF (ID22 beamline) using a high-resolution monochromatic beam (2x5 μm2 and 18 keV), and a collection geometry at 30° from the transmitted beam. This results in quantitative analysis of the solution down to the 20 ppm level. In the case of strontianite, kinetic data of the dissolution reaction showed instantaneous equilibration times at 400°C. Measured dissolution rates are essentially compatible with a first-order reaction mechanism and allow to retrieve the activation energy (E_A) for the dissolution of SrCO3 at HP-HT conditions. Taking into account activity coefficients, measured Sr2+ concentrations are used to determine the solubility constant (K_s) of SrCO3 at HP-HT conditions, allowing further thermodynamic modelling of carbonate dissolution. In the case of GeO2-rutile, we observed a gradient of the Ge concentration in the fluid. Hence, on the top of solubility measurements, it also allows to calculate the diffusion coefficients of Ge in high P-T aqueous fluids. This experiment thus shows the suitability of the SXRF technique for the in situ study of elemental diffusion in aqueous systems under high P-T conditions. Such data are essential for the

  2. In-situ X-ray diffraction study of phase transformations in the Am-O system

    SciTech Connect

    Lebreton, Florent; Belin, Renaud C.

    2012-12-15

    In the frame of minor actinides recycling, americium can be transmuted by adding it in UO{sub 2} or (U, Pu)O{sub 2} fuels. Americium oxides exhibiting a higher oxygen potential than U or Pu oxides, its addition alters the fuel properties. To comprehend its influence, a thorough knowledge of the Am-O phase equilibria diagram and of thermal expansion behavior is of main interest. Due to americium scarcity and high radiotoxicity, few experimental reports on this topic are available. Here we present in-situ high-temperature XRD results on the reduction from AmO{sub 2} to Am{sub 2}O{sub 3}. We show that fluorite (Fm-3m) AmO{sub 2} is reduced to cubic (Ia-3) C Prime -type Am{sub 2}O{sub 3+{delta}}, and then into hexagonal (P6{sub 3}/mmc) A-type Am{sub 2}O{sub 3}, which remains stable up to 1840 K. We also demonstrate the transitional existence of the monoclinic (C2/m) B-type Am{sub 2}O{sub 3}. At last, we describe, for the first time, the thermal expansion behavior of the hexagonal Am{sub 2}O{sub 3} between room temperature and 1840 K. - Graphical abstract: Americium dioxide was in situ studied by high-temperature X-ray diffraction. First, fluorite AmO{sub 2} is reduced to cubic C Prime -type Am{sub 2}O{sub 3+{delta}} and then transforms into hexagonal A-type Am{sub 2}O{sub 3}, which remains stable up to 1840 K. Then, we demonstrate the transitional existence of monoclinic B-type Am{sub 2}O{sub 3}. At last, we describe, for the first time, the thermal expansion of A-type Am{sub 2}O{sub 3} between room temperature and 1840 K. This work may contribute to a better understanding of Am oxide behavior. Highlights: Black-Right-Pointing-Pointer We realize an in-situ high-temperature X-ray diffraction study on an AmO{sub 2} sample. Black-Right-Pointing-Pointer Fluorite AmO{sub 2} transforms to cubic Am{sub 2}O{sub 3+{delta}} and then to hexagonal Am{sub 2}O{sub 3}. Black-Right-Pointing-Pointer Little-known monoclinic Am{sub 2}O{sub 3} is observed during the cubic

  3. Reduction process of Pd-containing La-Fe perovskite-type oxides by in-situ Dispersive X-ray absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    Uchiyama, T.; Kamitani, K.; Kato, K.; Nishibori, M.

    2016-05-01

    Reduction process of Pd-containing La-Fe perovskites was investigated by in-situ Pd K-edge dispersive X-ray absorption fine structure as well as mass spectroscopy. The prepared perovskite was characterized by a conventional X-ray absorption spectra to confirm the incorporation of cationic Pd into perovskite matrix. Under the reductive atmosphere (5 vol%H2/He), we found the presence of three reduction processes of Pd cations in perovskite structure. The segregation of Pd metal particles was observed from 200-400 oC although the cationic Pd species remained at 700 oC due to the strong metal-support interaction.

  4. In-situ small-angle X-ray scattering study of the precipitation behavior in a Fe-25 at.%Co-9 at.%Mo alloy

    SciTech Connect

    Zickler, Gerald A. Eidenberger, Elisabeth; Leitner, Harald; Stergar, Erich; Clemens, Helmut; Staron, Peter; Lippmann, Thomas; Schreyer, Andreas

    2008-12-15

    Fe-Co-Mo alloys show extraordinary mechanical properties which make them potential candidates for various high-performance applications. In the present study, for the first time, the precipitation behavior in a Fe-25 at.%Co-9 at.%Mo alloy was studied by small-angle X-ray scattering using high-energy synchrotron radiation. The specimens were isothermally aged in an in-situ furnace. The small-angle X-ray scattering patterns showed scaling behavior and were evaluated by employing a model function from the literature. This approach provides information about the characteristic length scale and the volume fraction of the precipitates in the alloy.

  5. Novel spectro-electrochemical cell for in situ/operando observation of common composite electrode with liquid electrolyte by X-ray absorption spectroscopy in the tender X-ray region.

    PubMed

    Nakanishi, Koji; Kato, Daisuke; Arai, Hajime; Tanida, Hajime; Mori, Takuya; Orikasa, Yuki; Uchimoto, Yoshiharu; Ohta, Toshiaki; Ogumi, Zempachi

    2014-08-01

    A novel spectro-electochemical cell for X-ray absorption spectroscopy in the tender X-ray region (TX-XAS) was designed and fabricated to investigate the electrochemical behavior of common battery materials with liquid electrolytes under in situ/operando conditions. The cell has several unique features, such as high X-ray transmittance, high signal to noise ratio, and high vacuum tightness. These features enable us quick and reliable XAS measurements. Operando P K-edge XAS measurements of an olivine-type LiFePO4 composite positive electrode were carried out to clarify its phosphorus environment during the electrochemical charging process. Results of spectral analysis show that there is no significant change in the oxidation state of phosphorus and in the coordination of the phosphate anions in the charging process, but a closer look of the consecutive XAS spectra suggests the shrinkage of the PO4 cage during the charging process, and the structural changes in a biphasic manner. These results demonstrate the usefulness of the cell for in situ/operando TX-XAS observations of light elements in practical batteries. PMID:25173283

  6. Novel spectro-electrochemical cell for in situ/operando observation of common composite electrode with liquid electrolyte by X-ray absorption spectroscopy in the tender X-ray region

    PubMed Central

    Nakanishi, Koji; Kato, Daisuke; Arai, Hajime; Tanida, Hajime; Mori, Takuya; Orikasa, Yuki; Uchimoto, Yoshiharu; Ohta, Toshiaki; Ogumi, Zempachi

    2014-01-01

    A novel spectro-electochemical cell for X-ray absorption spectroscopy in the tender X-ray region (TX-XAS) was designed and fabricated to investigate the electrochemical behavior of common battery materials with liquid electrolytes under in situ/operando conditions. The cell has several unique features, such as high X-ray transmittance, high signal to noise ratio, and high vacuum tightness. These features enable us quick and reliable XAS measurements. Operando P K-edge XAS measurements of an olivine-type LiFePO4 composite positive electrode were carried out to clarify its phosphorus environment during the electrochemical charging process. Results of spectral analysis show that there is no significant change in the oxidation state of phosphorus and in the coordination of the phosphate anions in the charging process, but a closer look of the consecutive XAS spectra suggests the shrinkage of the PO4 cage during the charging process, and the structural changes in a biphasic manner. These results demonstrate the usefulness of the cell for in situ/operando TX-XAS observations of light elements in practical batteries. PMID:25173283

  7. Novel spectro-electrochemical cell for in situ/operando observation of common composite electrode with liquid electrolyte by X-ray absorption spectroscopy in the tender X-ray region

    NASA Astrophysics Data System (ADS)

    Nakanishi, Koji; Kato, Daisuke; Arai, Hajime; Tanida, Hajime; Mori, Takuya; Orikasa, Yuki; Uchimoto, Yoshiharu; Ohta, Toshiaki; Ogumi, Zempachi

    2014-08-01

    A novel spectro-electochemical cell for X-ray absorption spectroscopy in the tender X-ray region (TX-XAS) was designed and fabricated to investigate the electrochemical behavior of common battery materials with liquid electrolytes under in situ/operando conditions. The cell has several unique features, such as high X-ray transmittance, high signal to noise ratio, and high vacuum tightness. These features enable us quick and reliable XAS measurements. Operando P K-edge XAS measurements of an olivine-type LiFePO4 composite positive electrode were carried out to clarify its phosphorus environment during the electrochemical charging process. Results of spectral analysis show that there is no significant change in the oxidation state of phosphorus and in the coordination of the phosphate anions in the charging process, but a closer look of the consecutive XAS spectra suggests the shrinkage of the PO4 cage during the charging process, and the structural changes in a biphasic manner. These results demonstrate the usefulness of the cell for in situ/operando TX-XAS observations of light elements in practical batteries.

  8. Phthalic acid complexation and the dissolution of forsteritic glass studied via in situ FTIR and X-ray scattering

    NASA Astrophysics Data System (ADS)

    Morris, Peter M.; Wogelius, Roy A.

    2008-04-01

    Multiple Internal Reflection Fourier Transform Infra-Red (MIR-FTIR) spectroscopy was developed and used for in situ flow-through experiments designed to study the process of organic acid promoted silicate dissolution. In tandem with the FTIR analysis, ex situ X-ray scattering was used to perform detailed analyses of the changes in the surface structure and chemistry resulting from the dissolution process. Phthalic acid and forsteritic glass that had been Chemically Vapour Deposited (CVD) onto an internal reflection element were used as reactants, and the MIR-FTIR results showed that phthalic acid may promote dissolution by directly binding to exposed Mg metal ion centers on the solid surface. Integrated infrared absorption intensity as a function of time shows that phthalic acid attachment apparently follows a t1/2 dependence, indicating that attachment is a diffusive process. The diffusion coefficient of phthalic acid was estimated to be approximately 7 × 10 -6 cm 2 s -1 in the solution near the interface with the glass. Shifts in the infrared absorption structure of the phthalate complexed with the surface compared to the solute species indicate that phthalate forms a seven-membered ring chelate complex. This bidentate complex efficiently depletes Mg from the glass surface, such that after reaction as much as 95% of the Mg may be removed. Surface depletion in Mg causes adsorbate density to fall after an initial attachment stage for the organic ligand. In addition, the infrared analysis shows that silica in the near surface polymerizes after Mg removal, presumably to maintain charge balance. X-ray reflectivity shows that the dissolution rate of forsteritic glass at pH 4 based on Mg removal in such flow-through experiments was equal to 4 × 10 -12 mol cm -2 s -1 (geometric surface area normalized). Reflectivity also shows how the surface mass density decreases during reaction from 2.64 g cm -3 to 2.2 g cm -3, consistent with preferential loss of Mg from the

  9. Advanced light element and low energy X-ray line analysis using Energy Dispersive Spectrometry (EDS) with Silicon Drift Detectors (SDD)

    NASA Astrophysics Data System (ADS)

    Salge, T.; Palasse, L.; Berlin, J.; Hansen, B.; Terborg, R.; Falke, M.

    2013-12-01

    Introduction: Characterization at the micro- to nano-scale is crucial for understanding many processes in earth, planetary, material and biological sciences. The composition of thin electron transparent samples can be analyzed in the nm-range using transmission electron microscopes (TEM) or, specific sample holders provided, in the field emission scanning electron microscope (FE-SEM). Nevertheless both methods often require complex sample preparation. An alternative method is to analyze bulk samples with a FE-SEM. In order to decrease the excitation volume for generated X-rays, low accelerating voltages (HV<10) are required. Consequently, only low to intermediate energy X-ray lines can be evaluated and many peak overlaps have to be deconvoluted since the high energy range is not available. Methods: A BRUKER Quantax EDS system with an XFlash Silicon Drift Detector acquired EDS spectra in spectrum images. To separate overlapping peaks, an extended atomic database [1] was used. For single channel EDS the electron beam current, solid angle, take-off angle and exposure time can be optimized to investigate the element composition. Multiple SDD setups ensure an even higher efficiency and larger collection angles for the X-ray analysis than single channel detectors. Shadowing effects are minimized in element distribution maps so that samples can be investigated quickly and sometimes in a close to natural state, with little preparation. A new type of EDS detector, the annular four channel SDD (XFlash 5060F), is placed between the pole piece and sample. It covers a very large solid angle (1.1 sr) and allows sufficient data collection at low beam currents on beam sensitive samples with substantial surface topography. Examples of applications: Results demonstrate that SDD-based EDS analysis contributes essential information on the structure at the micro- to nano scale of the investigated sample types. These include stardust analogue impact experiments [2], Chicxulub asteroid

  10. Quantitative Electron-Excited X-Ray Microanalysis of Borides, Carbides, Nitrides, Oxides, and Fluorides with Scanning Electron Microscopy/Silicon Drift Detector Energy-Dispersive Spectrometry (SEM/SDD-EDS) and NIST DTSA-II.

    PubMed

    Newbury, Dale E; Ritchie, Nicholas W M

    2015-10-01

    A scanning electron microscope with a silicon drift detector energy-dispersive X-ray spectrometer (SEM/SDD-EDS) was used to analyze materials containing the low atomic number elements B, C, N, O, and F achieving a high degree of accuracy. Nearly all results fell well within an uncertainty envelope of ±5% relative (where relative uncertainty (%)=[(measured-ideal)/ideal]×100%). Quantification was performed with the standards-based "k-ratio" method with matrix corrections calculated based on the Pouchou and Pichoir expression for the ionization depth distribution function, as implemented in the NIST DTSA-II EDS software platform. The analytical strategy that was followed involved collection of high count (>2.5 million counts from 100 eV to the incident beam energy) spectra measured with a conservative input count rate that restricted the deadtime to ~10% to minimize coincidence effects. Standards employed included pure elements and simple compounds. A 10 keV beam was employed to excite the K- and L-shell X-rays of intermediate and high atomic number elements with excitation energies above 3 keV, e.g., the Fe K-family, while a 5 keV beam was used for analyses of elements with excitation energies below 3 keV, e.g., the Mo L-family. PMID:26365439

  11. Limitations of ZAF correction factors in the determination of calcium/phosphorus ratios: Important forensic science considerations relevant to the analysis of bone fragments using scanning electron microscopy and energy-dispersive x-ray microanalysis

    SciTech Connect

    Payne, C.M.; Cromey, D.W. )

    1990-05-01

    A series of calcium phosphate standards having calcium/phosphorus (Ca/P) molar ratios of 0.50, 1.00, 1.50, and 1.67, respectively, was prepared for bulk specimen analysis using scanning electron microscopy (SEM) and energy-dispersive X-ray microanalysis (EDXA). The standards were mounted on carbon planchettes as either pure crystals or crystals embedded in epoxy resin. Ten different samples of each embedded and non-embedded standard were analyzed in a JEOL 100 CX electron microscope interfaced with a Kevex 8000 EDXA system using a lithium-drifted silicon detector and a multichannel analyzer. The Ca/P ratios were determined by calculating both net peak intensities without matrix corrections and atomic kappa-ratios using the MAGIC V computer program with ZAF correction factors for quantitative analysis. There was such extensive absorption of phosphorus X-rays in standards embedded in an epoxy matrix that the observed Ca/P ratios were statistically compatible with four different standards ranging in theoretical Ca/P ratios from 1.0 to 1.67. Although the non-embedded crystals showed a greater separation in the Ca/P ratios, both methods of preparation produced serious flaws in analysis. Direct application of the discovery of this caveat to the identification of suspected bone fragments for forensic science purposes is discussed.

  12. An in-situ X-ray diffraction study on the electrochemical formation of PtZn alloys on Pt(1 1 1) single crystal electrode

    NASA Astrophysics Data System (ADS)

    Drnec, J.; Bizzotto, D.; Carlà, F.; Fiala, R.; Sode, A.; Balmes, O.; Detlefs, B.; Dufrane, T.; Felici, R.

    2015-11-01

    The electrochemical formation and dissolution of the oxygen reduction reaction (ORR) PtZn catalyst on Pt(1 1 1) surface is followed by in-situ X-ray diffraction (XRD) and X-ray reflectivity (XRR) measurements. When the crystalline Pt surface is polarized to sufficiently negative potential values, with respect to an Ag/AgCl|KCl reference electrode, the electrodeposited zinc atoms diffuse into the bulk and characteristic features are observed in the X-ray patterns. The surface structure and composition during deposition and dissolution is determined from analysis of XRR curves and measurements of crystal truncation rods. Thin Zn-rich surface layer is present during the alloy formation while a Zn-depleted layer forms during dissolution.

  13. Corrosion of Ni in 1-butyl-1-methyl-pyrrolidinium bis (trifluoromethylsulfonyl) amide room-temperature ionic liquid: an in situ X-ray imaging and spectromicroscopy study.

    PubMed

    Bozzini, Benedetto; Gianoncelli, Alessandra; Kaulich, Burkhard; Kiskinova, Maya; Mele, Claudio; Prasciolu, Mauro

    2011-05-01

    This paper reports a pioneering application of soft X-ray scanning transmission microscopy (STXM), combined with micro-spot X-ray absorption spectroscopy (XAS) and X-ray fluorescence spectroscopy (XRF), for the investigation of the corrosion of metal electrodes in contact with room-temperature ionic liquids (RTIL). Using an open electrochemical cell in vacuo we explore some fundamental aspects of the aggressiveness of the 1-butyl-1-methyl-pyrrolidinium bis(trifluoromethylsulfonyl)amide ([BMP][TFSA]) RTIL towards Ni under in situ electrochemical polarisation. The possibility of imaging electrochemically-induced morphological features in conjunction with micro-XAS and XRF spectroscopies has provided unprecedented details regarding the space distribution and chemical state of corrosion products. PMID:21437296

  14. Lattice strain and damage evolution of 9-12/%Cr ferritic/martensitic steel during in situ tensile test by x-ray diffraction and small angle scattering.

    SciTech Connect

    Pan, X.; Wu, X.; Mo, K.; Chen, X,; Almer, J. D.; Ilavsky, J.; Haeffner, D. R.; Stubbins, J. F.; X-Ray Science Division; Univ. of Illinois

    2010-01-01

    In situ X-ray diffraction and small angle scattering measurements during tensile tests were performed on 9-12% Cr ferritic/martensitic steels. The lattice strains in both particle and matrix phases, along two principal directions, were directly measured. The load transfer between particle and matrix was calculated based on matrix/particle elastic mismatch, matrix plasticity and interface decohesion. In addition, the void or damage evolution during the test was measured using small angle X-ray scattering. By combining stress and void evolution during deformation, the critical interfacial strength for void nucleation was determined, and compared with pre-existing void nucleation criteria. These comparisons show that models overestimate the measured critical strength, and require a larger particle size than measured to match the X-ray observations.

  15. The influence of pressure on the phase stability of nanocomposite Fe89Zr7B4 during heating from energy dispersive x-ray diffraction

    NASA Astrophysics Data System (ADS)

    Leary, A. M.; Lucas, M. S.; Ohodnicki, P. R.; Kernion, S. J.; Mauger, L.; Park, C.; Kenney-Benson, C.; McHenry, M. E.

    2013-05-01

    Nanocomposite materials consisting of small crystalline grains embedded within an amorphous matrix show promise for many soft magnetic applications. The influence of pressure is investigated by in situ diffraction of hammer milled Fe89Zr7B4 during heating through the α → γ Fe transition at 0.5, 2.2, and 4.9 GPa. The changes in primary and secondary crystallization onset are described by diffusion and the energy to form a critical nucleus within the framework of classical nucleation theory.

  16. Effect of thermo-mechanical cycling on zirconium hydride reorientation studied in situ with synchrotron X-ray diffraction

    NASA Astrophysics Data System (ADS)

    Colas, Kimberly B.; Motta, Arthur T.; Daymond, Mark R.; Almer, Jonathan D.

    2013-09-01

    The circumferential hydrides normally present in nuclear reactor fuel cladding after reactor exposure may dissolve during drying for dry storage and re-precipitate when cooled under load into a more radial orientation, which could embrittle the fuel cladding. It is necessary to study the rates and conditions under which hydride reorientation may happen in order to assess fuel integrity in dry storage. The objective of this work is to study the effect of applied stress and thermal cycling on the hydride morphology in cold-worked stress-relieved Zircaloy-4 by combining conventional metallography and in situ X-ray diffraction techniques. Metallography is used to study the evolution of hydride morphology after several thermo-mechanical cycles. In situ X-ray diffraction performed at the Advanced Photon Source synchrotron provides real-time information on the process of hydride dissolution and precipitation under stress during several thermal cycles. The detailed study of diffracted intensity, peak position and full-width at half-maximum provides information on precipitation kinetics, elastic strains and other characteristics of the hydride precipitation process. The results show that thermo-mechanical cycling significantly increases the radial hydride fraction as well as the hydride length and connectivity. The radial hydrides are observed to precipitate at a lower temperature than circumferential hydrides. Variations in the magnitude and range of hydride strains due to reorientation and cycling have also been observed. These results are discussed in light of existing models and experiments on hydride reorientation. The study of hydride elastic strains during precipitation shows marked differences between circumferential and radial hydrides, which can be used to investigate the reorientation process. Cycling under stress above the threshold stress for reorientation drastically increases both the reoriented hydride fraction and the hydride size. The reoriented hydride

  17. In situ X-ray tomographic microscopy observations of vesiculation of bubble-free and bubble-bearing magmas

    NASA Astrophysics Data System (ADS)

    Pistone, Mattia; Caricchi, Luca; Fife, Julie L.; Mader, Kevin; Ulmer, Peter

    2015-12-01

    Magma degassing is thought to play a major role in magma fractionation, transport, storage, and volcanic eruption dynamics. However, the conditions that determine when and how magma degassing operates prior to and during an eruption remain poorly constrained. We performed experiments to explore if the initial presence of gas bubbles in magma influences the capability of gas to escape from the magma. Vesiculation of natural H2O-poor (<<1 wt.%) silicic obsidian glasses was investigated by in situ, high-temperature (above the glass transition) experiments using synchrotron-based X-ray tomographic microscopy with high spatial (3 μm/pixel) and temporal resolution (1 second per 3D dataset). As a validation, a second set of experiments was performed on identical starting materials using a Karl-Fisher titration setup to quantify the amount of extracted gas that escapes via volatile diffusion and/or bubble coalescence during vesiculation. In both sets of experiments, vesiculation was triggered by heating the samples at room pressure. Our results suggest that the presence of pre-existing gas bubbles during a nucleation event significantly decreases the tendency of bubbles to coalesce and inhibits magma outgassing. In contrast, in initially bubble-free samples, the nucleation and growth of bubbles is accompanied by significant coalescence and outgassing. We infer that volatile-undersaturated (i.e. bubble-free) magmas in the reservoirs are more likely to erupt effusively, while the presence of excess gas already at depth (i.e. bubble-bearing systems) increases the likelihood of explosive eruptions.

  18. Formation of tavorite-type LiFeSO4F followed by in situ X-ray diffraction

    NASA Astrophysics Data System (ADS)

    Eriksson, Rickard; Sobkowiak, Adam; Ångström, Jonas; Sahlberg, Martin; Gustafsson, Torbjörn; Edström, Kristina; Björefors, Fredrik

    2015-12-01

    The tavorite-type polymorph of LiFeSO4F has recently attracted substantial attention as a positive electrode material for lithium ion batteries. The synthesis of this material is generally considered to rely on a topotactic exchange of water (H2O) for lithium (Li) and fluorine (F) within the structurally similar hydrated iron sulfate precursor (FeSO4·H2O) when reacted with lithium fluoride (LiF). However, there have also been discussions in the literature regarding the possibility of a non-topotactic reaction mechanism between lithium sulfate (Li2SO4) and iron fluoride (FeF2) in tetraethylene glycol (TEG) as reaction medium. In this work, we use in situ X-ray diffraction to continuously follow the formation of LiFeSO4F from the two suggested precursor mixtures in a setup aimed to mimic the conditions of a solvothermal autoclave synthesis. It is demonstrated that LiFeSO4F is formed directly from FeSO4·H2O and LiF, in agreement with the proposed topotactic mechanism. The Li2SO4 and FeF2 precursors, on the other hand, are shown to rapidly transform into FeSO4·H2O and LiF with the water originating from the highly hygroscopic TEG before a subsequent formation of LiFeSO4F is initiated. The results highlight the importance of the FeSO4·H2O precursor in obtaining the tavorite-type LiFeSO4F, as it is observed in both reaction routes.

  19. A System for Conducting Sophisticated Mechanical Tests in Situ with High Energy Synchrotron X-Rays Final Technical Report

    SciTech Connect

    Jeremy Weiss

    2012-08-02

    This is the final technical report for the SBIR Phase I project titled 'A System for Conducting Sophisticated Mechanical Tests in Situ with High Energy Synchrotron X-Rays.' Experiments using diffraction of synchrotron radiation that help scientists understand engineering material failure modes, such as fracture and fatigue, require specialized machinery. This machinery must be able to induce these failure modes in a material specimen while adhering to strict size, weight, and geometric limitations prescribed by diffraction measurement techniques. During this Phase I project, Mechanical Solutions, Inc. (MSI) developed one such machine capable of applying uniaxial mechanical loading to a material specimen in both tension and compression, with zero backlash while transitioning between the two. Engineers currently compensate for a lack of understanding of fracture and fatigue by employing factors of safety in crucial system components. Thus, mechanical and structural parts are several times bigger, thicker, and heavier than they need to be. The scientific discoveries that result from diffraction experiments which utilize sophisticated mechanical loading devices will allow for broad material, weight, fuel, and cost savings in engineering design across all industries, while reducing the number of catastrophic failures in transportation, power generation, infrastructure, and all other engineering systems. With an existing load frame as the starting point, the research focused on two main areas: (1) the design of a specimen alignment and gripping system that enables pure uniaxial tension and compression loading (and no bending, shear, or torsion), and (2) development of a feedback control system that is adaptive and thus can maintain a load set point despite changing specimen material properties (e.g. a decreasing stiffness during yield).

  20. In situ X-ray Raman spectroscopy study of the hydrogen sorption properties of lithium borohydride nanocomposites.

    PubMed

    Miedema, Piter S; Ngene, Peter; van der Eerden, Ad M J; Sokaras, Dimosthenis; Weng, Tsu-Chien; Nordlund, Dennis; Au, Yuen S; de Groot, Frank M F

    2014-11-01

    Nanoconfined alkali metal borohydrides are promising materials for reversible hydrogen storage applications, but the characterization of hydrogen sorption in these materials is difficult. Here we show that with in situ X-ray Raman spectroscopy (XRS) we can track the relative amounts of intermediates and final products formed during de- and re-hydrogenation of nanoconfined lithium borohydride (LiBH4) and therefore we can possibly identify the de- and re-hydrogenation pathways. In the XRS of nanoconfined LiBH4 at different points in the de- and re-hydrogenation, we identified phases that lead to the conclusion that de- and re-hydrogenation pathways in nanoconfined LiBH4 are different from bulk LiBH4: intercalated lithium (LiCx), boron and lithium hydride were formed during de-hydrogenation, but as well Li2B12H12 was observed indicating that there is possibly some bulk LiBH4 present in the nanoconfined sample LiBH4-C as prepared. Surprisingly, XRS revealed that the de-hydrogenated products of the LiBH4-C nanocomposites can be partially rehydrogenated to about 90% of Li2B12H12 and 2-5% of LiBH4 at a mild condition of 1 bar H2 and 350 °C. This suggests that re-hydrogenation occurs via the formation of Li2B12H12. Our results show that XRS is an elegant technique that can be used for in and ex situ study of the hydrogen sorption properties of nanoconfined and bulk light-weight metal hydrides in energy storage applications. PMID:25231357