bluuebunny/crossref_metadata_2025_split huggingface dataset:
Micro-X-Ray Fluorescence Analysis on a Synchrotron Radiation Wiggler Beam Line
Authors: Gilfrich J.V. , Skelton E.F. , Qadri S.B. , Moulton N.E. , Nagel D.J. , Hu J. Z. 
Published: March 2019

AbstractIt has been well established over recent years that synchrotron radiation possesses some unique features as a source of primary x-rays for x-ray fluorescence analysis. Advantage has been taken of the high intensity emanating from the bending magnets of storage rings to develop x-ray microprobes utilizing apertures or focussing optics, or both, to provide a beam spot at the specimen of the order of micrometers. The use of insertion devices wigglers and undulatora, can further increase the available intensity, especially for the high energy photons. Beam Line X-17C at the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory, accepts the unmodified continuum radiation from a superconducting wiggler in the storage ring. Some initial XRF measurements have been made on this beam line using apertures in the 10 to 100 micrometer range. The fluorescent radiation was measured by an intrinsic Ge detector having an energy resolution of 300 eV at 15 kev, and located at 90° to the incident beam in the plane of the electron orbit. In samples containing many elements, detection limits of a few ppm were achieved with 100 μm beams.
Geometric Considerations in EDXRF to Increase Fluorescence Intensities and Reduce Background
Authors: Tolokonnikoff Igor 
Published: March 2019

AbstractTwo methods for improving the sensitivity of EDXRF will be presented. One method is to use a spherical geometry for the measurements. The analyzed specimen is made as a spherical layer (i.e., “orange rind”), with the exciting x-ray source and the detector being located in the inner surface of the specimen at opposite points on the diameter. The source radiation scattered into the detector is minimized by the 90° scattering angle at all points on the specimen. It has been shown that the sensitivity is improved by several times while earring out EDXRF measurements under conditions of spherical geometry as compared to the conventional flat arrangement.The other method we have investigated makes use of polarized radiation. The source radiation is polarized by scattering from a thin, low atomic number material. Higher energy radiation from the x-ray tube passes through the polarizer, where it impinges on a secondary fluorescer. This secondary radiation is then polarized by the same scatterer as the primary radiation. A quasi-monoenergetic polarized source is produced with maximized intensity by these means. It has been shown experimentally that the use of this polarized source for excitation leads to detection limits which are several times lower in the whole range of moderate energy. It has further been shown that the use of the easily added secondary target to the standard orthogonal polarization geometry increases the polarized beam intensity by 10-15%.
A Xanes Study of Square Copper(II) Complexes
Authors: Wakita Hisanobu , Yamaguchi Toshio , Adachi Hirohiko , Fujiwara Manabu , Yamashita Seiichi 
Published: March 2019

AbstractThe XANES (X-ray absorption near edge structure) spectra of copper(II) ions in solid state and in solution of the square-planar copper(II) complexes with tetraaza macrocycles were measured. The peaks in the measured XANES spectra shifted to lower energy side with increasing the electron density of central copper(II) ions. The molecular orbital calculations for the complexes were carried out by the DV-Xα method, and the theoretical XANES spectra were estimated. The clear chemical shift obtained by this XANES study is evaluated and leads to a new concept of π-back donation between the copper(II) complexes and counter anion in aqueous solution.
Fast and Simple Routine Determination of Bromine by XRF in Wet Blood Serum Microsamples Evaluation of Errors
Authors: Shenberg C. , Gilat J. , Mantel M. 
Published: March 2019

AbstractA specific XRF method, developed at the Soreq Nuclear Research Centre, was applied to the determination of bromine in blood. The method is based on excitation with a Mo X-ray tube and detection of the fluorescent Br K X-rays by a Si (Li) detector. Serum microsamples (300 μL) are counted directly, without drying, for 100 sec, The detection limit obtained under these conditions is 0.6 ppm Br, The overall precision of the method was found to be ±3.1%. The different parameters which contribute to the total error of the method were studied, A survey of the bromine concentration in the blood serum of industrial workers exposed to bromine compounds was carried out.
Stastitical Comparison of Analytical Results Obtained by Pressed Powder and Borate Fusion XRF Spectrometry for Process Control Samples of a Lead Smelter
Authors: Metz Jorg G.H. , Davey David S. 
Published: March 2019

AbstractTwo sample preparation procedures for XRF determination of critical elements in process control samples of a lead smelter have been compared. The two methods, pressed powder(PP) and borate fusion(BF) were used in the analysis of (in order of importance) lead, zinc, copper, sulphur, arsenic and the flux elements (FeO, MnO, Al2O3, CaO, MgO and SiO2). The techniques were applied to three points in the overall lead-zinc-copper production process.The three sample types have been selected to allow comparison between the BF and PP methods, where the PP method suffers from difficulties with particle size, moisture absorption or composition variation.The BF technique was found to give better precision (typically 0.2 to 1% RSD) than the PP approach (typically 0.8 to 9% RSD), and to give better accuracy as found using reference materials. The stability of the BF bead over time is also of advantage in quality control. The flexibility and reliability of the BF technique has lead to its acceptance, and in part, to changes in the overall smelter analysis structure.
In-Process Coating Layer Analysis of Galvannealed Steel Sheets with Monochromatic Incident X-Rays
Authors: Kato Hiroharu , Imai Kiyotaka , Tanabe Hideya 
Published: March 2019

AbstractA new method, for the on-line determination of the composition and the coating weight of galvannealed (Zn-Fe-alloy-coated) steel sheets using monochromatic incident x-rays with two optical systems, is described. In the case of galvannealed steel sheets, it is difficult to determine the composition and the coating weight precisely by simple XRF, because fluorescent x-rays of Iron are emitted not only from the coating layer but also from the underlying steel sheets. We have developed an on-line analyzer with two optical systems which are different in incident angles, take-off angles and wavelengths of monochromatic incident x-rays. We determine the composition and the coating weight by solving simultaneous equations of the data which we derive using two optical systems. Using monochromatic x-rays enabled us to obtain high precision with high speed. We considered en-or factors in on-line measurement such as statistical error or fluctuation of the distance between the sensor head and steel sheets. This on-line analyzer has been applied to the continuous galvanizing line in our Fukuyama works successfully. As a result, we have been able to significantly improve product quality.
A New Nondestructive Quantitative Composition Depth Profiling Technique Based on X-Ray Excited Electron Emission
Authors: Backaleinickov L.A. , Konnikov S.G. , Pogrebitsky K.Ju. , Yuriev Y.N. , Vereninov A.A. , Svagera R. , Kaitna R. , Barnegg-Golwig G. 
Published: March 2019

AbstractThe physical basis for x-ray induced secondary electron emission in the range of the absorption edges is described. Applications of this principle for nondestructive composition determination and for nanometer resolved quantitative composition depth profiling are illustrated. A new commercial type of scientific instrument is presented which can be used for this new technique, and for almost all methods that require x-ray photon beam probing.All the methods described in this paper are based on the same phenomenon, chat is, the phenomenon of the jump-like increase of x-ray photoabsorption in the vicinity of the x-ray absorption edges of the chemical elements of the sample.
A Novel Scanning X-Ray Diffracto-Microscope/X-Ray Powder Diffractometer using Converged X-Ray Beam
Authors: Yukino Ken , Okamura Pujio P. , Biozaki Hiroshi , Kobayashi Yuji , Yamada Yoshiyuki 
Published: March 2019

AbstractA new type of scanning X-ray diffracto-microscope (SXDM) / X-ray powder diffractometer (XPD) which uses a converged incident beam, was designed, manufactured, and some of its basic characteristics were examined. The optical system consists of asymmetric reflection type curved crystal monochromators for both incident and reflection beams, a detector (FSPC, X-ray film, IP, nuclear plate), a translation mechanism for the specimen and also for the detector.
Total Reflectance X-Ray Spectrometry
Authors: Aiginger Hannes , Wobrauschek Peter 
Published: March 2019

AbstractThe reduction of the background in x-ray fluorescent spectra is achieved by total reflection of the primary x-rays at a plane, smooth surface of a suitable reflector material. This effect essentially reduces the background caused by scattering of the primary photons from the substrate, thus improving the lower limits of detection in x-ray fluorescence analysis (XRF). Introducing additional to the reflector-substrate another reflector in the primary beam, this affects the spectral distribution of the exciting radiation (“high energy cutoff”). The result is an improved background, where detection limits of picogram amounts or concentrations in the ppb range are attainable for medium Z elements with energy dispersive detectors.
Use of Primary Beam Filtration in Estimating Mass Attenuation Coefficients by Compton Scattering
Authors: O'Connor B. H. , Chang W–J. 
Published: March 2019

AbstractMass attenuation coefficients (MACs) are frequently estimated over a range of wavelengths in x-ray spectrometry from the intensity of the Compton peak IC associated with a prominent tube line. The MAC μλ at wavelength λ is estimated from the MAC at the Compton wavelength λC with the approximations μλ α μC and μC α 1/IC. Systematic errors may introduce absorption edge bias (AEB) effects into the results, caused by sample components vith absorption edges between λc and λ. A procedure is described which eliminates AEB effects by measuring IC using emission radiation from a primary beam filter.
A Soft X-ray Experimental Facility
Authors: Gilfrich John V. , Nagel David J. , Fatemi Mohammad , Bleach Richard D. , Hudson Karrol R. 
Published: March 2019

AbstractA high vacuum soft x-ray source has been coupled to a large volume experimental chamber to provide a versatile facility for x-ray investigations in the energy range of 0.1 to 10 kev. The source chamber presently contains a modified Herike tube, but can employ any of a variety of source designs. The large experimental chamber is equipped with a kinematic mount to position a number of x-ray optical instruments. The source and experimental chambers are connected through a high vacuum valve/shutter, and are pumped separately with provision for a thin window to isolate one from the other, single and double crystal spectrometers have been used in the experimental chamber. A variable chord diffractometer/reflectometer using double crystal monnotiromatization has been designed, in addition, the facility has been used to expose photoresists in x-ray lithography tests.
EDXRF Determination of Major and Minor Elements in Compound Fertilizers
Authors: Christensen Leif Højslet , Rasmussen Leif 
Published: March 2019

AbstractThe combination of the energy-dispersive x-ray fluorescence technique and a backscatter/fundamental parameter-based matrix correction approach provides a new and unique solution to elemental analyses of fertilizers. This is demonstrated by means of results obtained for three reference materials and a range of in-house fertilizers. The results further demonstrate problems of sample preparation as well as the precision and accuracy of the method.
Analysis of Wet-Process Phosphoric Acid and By-Product Filter Cake by X-ray Spectrometry
Authors: Wilhide Wendell D. , Ash Doris H. 
Published: March 2019

AbstractRapid X-ray fluorescence (XRF) analytical methods have been developed for analyzing wet-process phosphoric acid liquid samples and by-product calcium sulfate filter-cake solids. Liquid acid samples are neutralized by lithium carbonate and pressed-pellet, dry sample wafers are prepared for a nine-element analysis. Filter-cake solids are dehydrated to anhydrous calcium sulfate for a ten-element analysis. Hovel sample preparation techniques are described which permit maximum use of the automated XRF system for process control. Precision obtained for typical materials is compared with results of conventional chemical analyses.
Strain Measurements on Single Crystals and Macrograins with the Aid of an Automated Phi-Psi Goniometer
Authors: Pathiraj B. , Koster H. , Nijssen A. M. , Willemse P. F. , Kolster B. H. 
Published: March 2019

AbstractA back reflection goniometer with possibilities of Φ and Ψ rotations of the specimen was developed for stress-strain analysis in single crystals and macrograins and was completely automated. A computer software in PASCAL language was developed. The system is capable of i) optimising the Φ, Ψ and 2θ positions for a reflection, ii) scanning all the specified reflections one after another, iii) determining the lattice spacings after applying suitable corrections to the intensity data and iv) correcting the lattice spacings for temperature variations. Experimental results of measurements on an aluminum single crystal in annealed and plastically deformed conditions are presented to indicate the speed, reproducibility and accuracy of measurements. Principal sources of errors and their control in the developed system are discussed.
Quantitative XRF Analysis Using the Fundamental Algorithm
Authors: Rousseau Richard M. 
Published: March 2019

AbstractA modern theoretical method using the Fundamental Algorithm to correct for matrix effects in X-Ray Fluorescence (XRF) analysis is described. This powerful quantitative method combines the practical flexibility of influence coefficient concepts and the theoretical exactness of the fundamental parameter technique. This method is in full agreement with the treatment of the physics as proposed by Sherman and can be applied to the analysis of any sample types. It offers the maximum of accuracy limited only by the quality of sample preparation. The special calibration procedure associated with the Fundamental Algorithm is explained. This procedure allows the matching of theoretical formalism to experimental data of each individual laboratory. Finally and obviously, this approach requires a computer program to be applied. Some important guidelines are given to help XRF analysts to select the XRF program appropriate to their needs.
Drift in Energy Calibration of Energy Dispersive X-ray Fluorescence Analyzers and Its Correction
Authors: Liu Zhaogui 
Published: March 2019

AbstractIt is to be expected that drift will occur in the energy calibration of Energy Dispersive X-Ray Fluorescence Analysis (EDXRFA) spectrometers. The error thus caused in the measured x-ray intensity is evaluated in this paper. In order to minimize the error, two steps are necessary. The first is to make a new energy calibration to follow the trend of the drift. The second step involves moving the regions of the characteristic peaks to accommodate the drift. Software has been developed to accomplish both steps automatically.
High-Temperature Displacement Measurement Using a Scanning Focused X-ray Line Source
Authors: Jordan E. H. , Canistraro H. A. , Pease D. M. , Brewe D. 
Published: March 2019

AbstractA non-contacting displacement measuring system utilizing focussed x-rays is being developed for use in hostile environments. Ultimately, this method will be used to measure mechnical strain under adverse conditions such as high temperatures, flame, cutting fluids, and gases with high velocity and pressure gradients. The foundation of the technique is the use of xrays, which are immune to the various environmental factors mentioned above. The proposed system uses a highly focussed, intense x-ray line which is scanned across markers that fluoresce secondary radiation. This secondary radiation level is then monitored using a photon detector and marker-focussed line overlap can be discerned. These targets can be used as fiducial markers demarcating a gage length, and the change in pointing angle of the focussed beam at target overlap is used as a measure of relative displacement. The present experimental systemcan consistently resolve 1.27 microns at ambient conditions, and 2.54 microns have been measured at a target temperature of 1900 de-grees F through an open flame. Given the performance of the current apparatus, equipment improvements should permit increases in resolution by a least a factor of 10 and measurements at much higher temperatures are possible.
X-ray Fluorescence as a Problem-Solving Tool in the Paper Industry
Authors: Istone William K. , Collier John M. , Kaplan Jay A. 
Published: March 2019

AbstractWavelength dispersive X-ray fluorescence spectrometry (WDXRF) is used for many types of routine analysis in the paper industry. Examples of routine elemental analysis include analysis of pigments in papers and coatings, analysis of fuels, and analysis of paper-mill waste. In the central analytical laboratory, however, WDXRF is frequently called upon in unique problem-solving situations. In some cases, these problem-solving applications later develop into routine methods.In this paper, three examples of WDXRF being used as a problem-solving technique are discussed. These situations are: the determination of the cause of ring formation in lime-kilns, failure analysis of ceramic limekiln linings, and the determination of pigment distributions in alkaline papers.
Measurement of Mass Absorption Coefficients Using Compton-Scattered Cu Radiation in X-ray Diffraction Analysis
Authors: Chipera Steve J. , Bish David L. 
Published: March 2019

AbstractThe mass absorption coefficient is a useful parameter for quantitative characterization of materials. If the chemical composition of a sample is known, the mass absorption coefficient can be calculated directly. However, the mass absorption coefficient must be determined empirically if the chemical composition is unknown. Traditional methods for determining the mass absorption coefficient involve measuring the transmission of monochromatic X-rays through a sample of known thickness and density. Reynolds (1963,1967), however, proposed a method for determining the mass absorption coefficient by measuring the Compton or inelastic X-ray scattering from a sample using Mo radiation on an X-ray fluorescence spectrometer (XRF). With the recent advances in solid-state detectors/electronics for use with conventional powder diffractometers, it is now possible to readily determine mass absorption coefficients during routine X-ray diffraction (XRD) analyses.Using Cu Kα radiation and Reynolds’ method on a Siemens D-500 diffractometer fitted with a Kevex Si(Li) solid-state detector, we have measured the mass absorption coefficients of a suite of minerals and pure chemical compounds ranging in μ/ρ from graphite to Fe-metal (μ/ρ = 4.6-308 using Cu Kα radiation) to ±4.0% (lσ). The relationship between the known mass absorption coefficient and the inverse count rate is linear with a correlation coefficient of 0.997. Using mass absorption coefficients, phase abundances can be determined during quantitative XRD analysis without requiring the use of an internal standard, even when an amorphous component is present.
Evaluation of Reference X-ray Diffraction Patterns in the ICDD Powder Diffraction File
Authors: McCarthy G. J. , Holzer J. M. , Syvinski W. M. , Martin K. J. , Garvey R. G. 
Published: March 2019

AbstractProcedures and tools for evaluation of reference x-ray powder patterns in the JCPDSICDD Powder Diffraction File are illustrated by a review of air-stable binary oxides. The reference patterns are evaluated using an available microcomputer version of the NBS*A1DS83 editorial program and PDF patterns retrieved directly from the CD-ROM in the program's input format. The patterns are compared to calculated and experimental diffractograms. The majority of the oxide patterns have been found to be in good agreement with the calculated and observed diffractograms, but are often missing some weak reflections routinely observed with a modern diffractometer. These weak reflections are added to the PDF pattern. For the remainder of the phases, patterns are redetermined.
X-ray Topography and TEM Study of Crystal Defect Propagation in Epitaxially Grown AIGaAs Layers on GaAs(001)
Authors: Bassignana L. C. , Macquistan D.A. , Clark D.A. 
Published: March 2019

AbstractAsymmetric crystal topography (ACT) in reflection and transmission electron microscopy (TEM) were used to investigate the crystal quality of both typical GaAs substrates and AIGaAs epitaxial layers grown on these substrates. ACT topographs of large sections of 75mm GaAs wafers revealed the presence of several types of crystal defects. All the GaAs wafers surveyed showed the presence of low angle grain boundaries which usually extended over a significant portion of the wafer. In addition, the well-known cell structure dislocation network was always observed in semi-insulating wafers. Less common but often present were inclusions and precipitates. The n-type (Si doped) substrates showed a typical cross-hatched pattern. ACT topography also easily revealed the crystal damage caused by wafer grinding.Epitaxial layers of AIGaAs were grown by conventional molecular beam epitaxy on these characterized GaAs substrates. ACT topography was used to examine separately the epitaxial layers and substrate crystals. Layers which were grown below the pseudomorphic limit showed crystal features identical to the GaAs substrate on which they were grown and the substrate was unaffected by the presence of the epitaxial layer. AJAs layers which were grown above the pseudomorphic limit were severely dislocated: TEM confirmed the presence of misfit dislocations at the interface. The substrate in this case also showed the presence of crosshatching indicating the the extension of the dislocation strain field into the substrate.
Substructure-Magnetic Property Correlation in Fe/Ag Composite Thin Films
Authors: Reed C. P. , DeAngelis R. J. , Zhang Y. X. , Liou S. H. , Jacob R. J. 
Published: March 2019

AbstractA series of nanostructured Fe/Ag metal films were produced at various substrate temperatures to determine their magnetic characteristics. The magnetic coercivity was found to increase with the diffracting-particle size which is process controlled. The films produced at low substrate temperature (<200°C) consisted of small metallic clusters of Ag (<100 Å). As the substrate temperature was increased, the films exhibited increased crystallinity and larger diffracting-particle size. The position of the maximum in the particlesize distribution function and the width of the function increased with substrate temperature.