bluuebunny/crossref_metadata_2025_split huggingface dataset:
K‐shell fluorescence yields of some elements from nuclear decay parameters
Authors: Sidhu N. P. S. , Grewal B. S. , Sahota H. S. 
Published: May 2005

AbstractThe K‐shell fluorescence yields of nine elements with atomic numbers 33, 55, 59, 63, 66, 69, 71, 73 and 80 were measured from a knowledge of nuclear decay parameters. The results are in good agreement with earlier measurements and the fitted values of Bambynek et al. The merits and demerits of the method are discussed.
Quantitative estimates of potassium in whole blood samples from diabetic
Authors: Venkateswara Rao N. , Bhuloka Reddy S. , Narayana D. G. S. , Satyanarayana G. , Sastry D. L. 
Published: May 2005

AbstractAn energy‐dispersive x‐ray spectrometer was used to make a quantitative estimate of potassium in whole blood samples from diabetic subjects and controls. A single standard method employing a fundamental parameter approach was followed for the quantification of potassium x‐ray intensities. The results show that the potassium levels in diabetics are about double those in controls.
Photon‐excited K X‐ray fluorescence cross‐section measurements for some low‐Z‐elements
Authors: Rani Anita , Koshal Rajesh K. , Chaturvedi S. N. , Nath N. 
Published: May 2005

AbstractX‐ray fluorescence cross‐section for Kα x‐ray lines were measured for the light elements Na, Mg, Al, Si, S, Cl and K relative to Ca at a photon excitation energy of 5.97 keV (Mn K x‐ray). A windowless retractable Kevex Si(Li) detector system having an energy resolution of 146 eV at 6.4 keV was used for the detection of the characteristic K x‐rays. The measurements were performed in a vacuum chamber maintained at a pressure of ca 10−7 Torr using a 55Fe radioactive excitation source and targets of ultra‐pure elements/compounds of the above‐mentioned elements. Cross‐sections were also calculated using photoelectric cross‐sections, fluorescence yields and the fractional x‐ray emission rates. Measured and calculated x‐ray fluorescence cross‐sections agreed within reasonable limits.
Optimization and coupled absorption effects in diamond anvil energy‐dispersive X‐ray diffraction measurements
Authors: Cavaleri Mark E. , Stout James H. 
Published: May 2005

AbstractOptimization of EDXRD measurements using the diamond anvil high‐pressure cell varies with the particular experimental objectives. In the case of P‐V‐T equation of state studies, the controllable factors are adjusted to optimize the precision and accuracy of the interplanar spacing measurements. The identification of new phases requires the optimization of lattice parameter determinations and the minimization of the effects of thickness on the relative intensities, whereas for reaction rate studies the various factors are adjusted to maximize the absolute intensities of the peaks of interest. In each of these cases there are trade‐offs in the effects of the individual factors that must be made in order to optimize the measurements. Of these factors, the sample absorption is often the most important. For example, profound changes in the relative intensities of diffraction peaks during normal compression studies are caused by the coupled effects of normal sample absorption as the sample thins and the energy dependence of the absorption coefficient. Such changes in relative intensities could be incorrectly attributed to uniaxial stress, residual stress, order‐disorder phenomena or element partitioning. Coupled absorption effects in the presence of a powdered, internal standard also have an important bearing on optimizing the relative proportions of admixed standard and sample.
Method for the determination of Mg and Si contents in aluminium alloys
Authors: Szalóki I. 
Published: May 2005

AbstractAn XRF method was developed for the determination of Mg and Si in aluminium alloys in the range from 0.1 to 0.7 wt%, using a Si(Li) semiconductor detector, a 3H/Ti ring‐shaped radioactive source and a microcomputer. The Mg Kα and Al Kα lines were separated both with the help of library spectra (deconvolution) and with an Se absorption edge filter. The optimum values of the geometrical parameters were determined. Two 3H/Ti sources, covered and not covered with Cr, were tested. The standard deviations of concentrations determined by different methods was compared.
X‐ray K absorption studies on some cobalt thiosemicarbazones
Authors: Shrivastava B. D. , Joshi S. K. , Pandeya K. B. 
Published: May 2005

AbstractThe x‐ray K absorption edges of Co in some thiosemicarbazones were recorded. The results are discussed qualitatively in terms of molecular symmetry and the nature of the ligand. The extended x‐ray absorption fine structure associated with the K absorption edge of cobalt in these thiosemicarbazones was also studied. The average metalligand bond lengths in these complexes were calculated.
New organic crystals as x‐ray monochromators: Triphenylbenzene and thalliúm tartrate
Authors: Charbonnier M. , Romand M. , Grubis B. 
Published: May 2005

AbstractThe usefulness of analysing crystals for x‐ray spectrometry is governed, to a large extent, by their angular dispersion and reflection efficiency, but other features such as crystal fluorescence must also be taken into account. Experimental results are presented that illustrate the performances of two organic crystals: (i) triphenylbenzene, which constitutes an attractive alternative to ammonium dihydrogen phosphate for the determination of magnesium in cements and other calcium‐containing matrices, and (ii) thallium tartrate, which may be recommended for the determination of sodium and possibly magnesium instead of the widely used thallium acid phthalate.
X‐Ray spectrometric determination of minor element contents in stainless steels
Authors: Smagunova A. N. , Molchanova E. I. , Pliner L. N. , Finkelshtein A. L. 
Published: May 2005

AbstractModels of the dependence of the background intensity on the chemical composition of a specimen for different conditions of analysis are presented. On the basis of these models, a new technique for background correction in the x‐ray spectrometry of homogeneous materials with widely varying composition is suggested. Criteria for evaluation of the necessity for background correction are discussed.
Determination of some trace elements in high‐purity tantalum metal by thin‐film x‐ray fluorescence spectrometry
Authors: Eddy B. T. , Balaes A. M. E. 
Published: May 2005

AbstractThe determination of niobium, molybdenum, tungsten, iron and titanium in tantalum metal is described. After dissolution of the metal and extraction of the tantalum by a chromatographic method using tributyl phosphate, the trace elements are determined on thin‐film samples by x‐ray fluorescence spectrometry. The thin‐film samples are prepared either by spotting the sample solutions directly on to filter‐paper or by coprecipitation with indium. The limits of detection on the thin film are 0.05–0.7 μg, depending on the element being measured.
Evaluation of the armstrong–buseck correction for automated electron probe X‐ray microanalysis of particles
Authors: Storms Hedwig M. , Janssens Koen H. , Török Szabina B. , Van Grieken René E. 
Published: May 2005

AbstractThe Armstrong–Buseck correction for absorption effects in electron probe x‐ray microanalysis of particles considers seven specific particle shapes, and for these geometries exact correction equations are used. This procedure implies that the analyst has to associate the particle to be analysed with a certain particle type; an arbitrary relative thickness is sometimes assumed. A theoretical study was made of this absorption correction as a function of the particle composition, type and thickness for micrometre‐sized particles. It appears that a correct choice of the particle type is critical. However, when the analytical results are normalized to 100%, the differences between the models are much less pronounced, and it is justified to assume a spherical model in all cases.
Quantification of continuous and characteristic tube spectra for fundamental parameter analysis
Authors: Ebel H. , Ebel M. F. , Wernisch J. , Poehn Ch. , Wiederschwinger H. 
Published: May 2005

AbstractThe response of white radiation, expressed as the number of photons per second and energy interval versus energy, is an essential quantity in quantitative x‐ray fluorescence analysis using fundamental parameters. Our investigations gave the best fit of experimental results obtained from ten elements (6 ≤ Z ≤ 82) in the energy range of photons from 3 to 30 keV by the equation
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Contribution due to excitation by scattered photons in measurements of L x‐ray cross‐sections
Authors: Singh Surinder , Mehta Devinder , Kumar Sudhir , Garg M. L. , Singh Nirmal , Mangal P. C. , Trehan P. N. 
Published: May 2005

AbstractThe relative contribution to the production of target L x‐rays by the scattered and K x‐ray parts of excitation spectra from different secondary excitors in annular source geometry is estimated. In contrast to the observations of N. Singh et ul., who made similar measurements using triaxial geometry, we found only a small contribution to the production of L x‐rays by the scattered part of the excitation spectrum in comparison with that by the K x‐ray part. We crosschecked the observations by measuring L x‐ray cross‐sections for five elements, Pr, Nd, Sm, Tb and Yb, at 22.6 keV by two methods: (i) using a 109Cd radioisotope source in the direct excitation mode and (ii) using a secondary excitor of Ag with a 241Am radioisotope source as the primary excitor, in annular source geometry. The results obtained by the two methods are found to be in good agreement.
Semi‐empirical schemes for x‐ray attenuation coefficients in the context of PIXE
Authors: Campbell J. L. , Deforge D. 
Published: May 2005

AbstractVarious semi‐empirical schemes for generating x‐ray attenuation coefficients, μ/ρ, devised primarily for use in electron probe microanalysis, are considered for application in the PIXE analysis of thick specimens where the relevant x‐ray energy region is 1–40 keV. Using selected high‐accuracy experimental data, it is shown that current theoretical values of μ/ρ agree better with the data than do the various schemes. The errors transmitted into PIXE analysis by use of the theoretical values are estimated, and a new parameterization of these values suitable for microcomputer use is justified and tested.
Diffraction of a high‐energy characteristic x‐ray by a perfect crystal
Authors: Short M. A. , Fallon M. R. 
Published: May 2005

AbstractThe diffraction of high‐energy characteristic x‐ray lines, which have relatively large intrinsic widths, by perfect single crystals, which have acceptance angles much less than these line widths, is discussed. Experiments using Bi Kα1, which has an equivalent FWHM of 0.0013°, and an asymmetrically cut Si (111) crystal, having acceptance angles of 0.0002° and 0.0004°, showed that only a small fraction of the total characteristic line was, in fact, diffracted by the crystal.
Holes in the background in XRS
Authors: Self P. G. , Norrish K. , Milnes A. R. , Graham J. , Robinson B. 
Published: May 2005

AbstractSharp negative lines have been observed in wavelength‐dispersive (WD) spectra. These ‘holes’ can cause severe errors when analysing for trace elements near the lower levels of detection. The existence of the holes is explained in terms of diffraction from crystailographic planes other than those used in the WD analysis, and an overview is given of the theory necessary to predict the occurrence of the holes with emphasis on LiF(200) analysing crystals.
Analysis of NBS and other reference materials for testing the validity of the α‐parameter correction method in pixe
Authors: Aloupogiannis P. , Robaye G. , Weber G. , Delbrouck‐Habaru J. M. , Roelandts I. 
Published: May 2005

AbstractA previously described method for correction of PIXE data based on the measurement of proton energy loss, ΔE, and x‐ray transmission factors has been tested on international geological, biological and ore reference materials. After a short review of the sample preparation method and the experimental procedures, the analytical results, precision and accuracy are discussed.
Calculation of x‐ray fluorescence intensities from bulk and multilayer samples
Authors: De Boer D. K. G. 
Published: May 2005

AbstractEquations are derived for the calculation of x‐ray fluorescence intensities from bulk and multilayer samples. Both intra‐ and interlayer secondary fluorescence intensities are expressed analytically, in terms of the exponential‐integral function. It is shown that calculations are performed much faster with this method than with a previous method using numerical integration. As an illustration, some examples of intensity calculations are given for a thin layer on a substrate.
K x‐ray fluorescence cross‐section measurements of some elements in the energy range 8–47 keV
Authors: Singh Surinder , Rani Rakesh , Mehta Devinder , Singh Nirmal , Mangal P. C. , Trehan P. N. 
Published: May 2005

AbstractThe Kα and Kβ XRF cross‐sections were measured for Sc, Cr, Fe, Ni, Ga, Sr, Nb, Rh, Pd and Te at eight excitation energies ranging from 8 to 47 keV using energy‐dispersive XRF. The Kα and Kβ cross‐sections for all the elements were in general agreement with the theoretical values calculated using photoionization cross‐sections based on Hartree‐Slater potentials and Kβ/Kα intensity ratios based on Hartree‐Fock theory.
Structural studies of glassy semiconducting Se80 − xTe20Inx alloys
Authors: Kumar Arvind , Husain M. , Swarup S. , Nigam A. N. , Kumar A. 
Published: May 2005

AbstractThe shift of the K‐absorption edge (ΔEK) was measured in Se80‐xTe20Inx, where 0 ≤ x ≤ 20. It is observed that the K‐edge of Se shifts progressively towards the lower energy side as the In concentration increases from 0 to 15 at.‐%. However, at higher concentrations, the relative shift starts to decrease. The results are in accordance with the Pauling concept of electronegativity and indicate that the nature of the bonds is iono‐covalent in these glasses, as found in many crystalline solids. The composition dependence of the edge shift is also discussed in terms of the structure of the Se‐Te system.
Instrumental developments in total reflection x‐ray fluorescence analysis for K‐lines from oxygen to the rare earth elements
Authors: Wobrauschek P. , Kregsamer P. , Streli C. , Aiginger H. 
Published: May 2005

AbstractDevelopments in the instrumentation of total reflection x‐ray fluorescence analysis (TXRF) are presented. Different ways of obtaining optimized primary radiation are discussed, and a new double reflector‐collimator is introduced. To increase the number of detectable elements, special devices for low‐Z and high‐Z determinations are presented, in addition to a modular TXRF attachment for versatile applications. Detection limits achieved by various types of excitation conditions are given. TXRF has been shown to be a powerful analytical tool for trace element determinations in various samples.
Study of oxygen peak shifts among some minerals using a tungsten–silicon multilayer pseudo‐crystal
Authors: Liang Long‐Cheng 
Published: May 2005

AbstractA study of oxygen Kα peak shifts using an electron probe microanalyzer with a W–Si multilayer pseudo‐crystal (2d = 59.8 Å) shows a significant peak shift (0.024–0.043 Å) between simple oxide minerals (e.g. quartz) and minerals containing complex oxygen radicals (e.g. SO, CO and PO). The peak shift of the complex oxygen radicals toward the lower wavelength (or higher energy) side of the simple oxides may indicate a relatively stronger bonding energy inside these radicals than that of the simple cation—oxygen bond. In the direct determination of oxygen, a peak count reduction could occur as a result of this peak shift effect if unsuitable oxygen standards are used.
Measurement of M‐shell x‐ray production cross‐sections using 5.96‐keV photons
Authors: Garg R. R. , Singh S. , Shahi J. S. , Mehta D. , Singh N. , Trehan P. N. , Kumar S. , Garg M. L. , Mangal P. C. 
Published: May 2005

AbstractM‐shell x‐ray production/fluorescence (M XRF) cross‐sections for five elements with 81 ≤ Z ≤ 92 were measured at 5.96‐keV incident photon energy using thin targets. From the measured M XRF cross‐sections the average M‐shell fluorescence yields were derived. Experimental results for XRF cross‐sections and fluorescence yields were compared with theory. The experimental results were found to be higher than the theoretical values by 10–17%. Further experimental investigations on M XRF cross‐sections for more elements at different excitation energies are required in order to check the validity of the theoretical parameters used to calculate the M XRF cross‐sections.
X‐ray microfluorescence analysis inside and outside the electron microscope
Authors: Pozsgai I. 
Published: May 2005

AbstractThe possibilities of carrying out x‐ray microfluorescence analysis are reviewed. The main approaches are converting the electron optical column of an electron microscope into a transmission x‐ray tube, using microfocusing x‐ray tubes, combining x‐ray tubes with capillary techniques, combining x‐ray tubes with monochromators and applying synchrotron radiation.
SEM, EDX and XRD studies of the scales formed on the Fe–Mn–Al–C system in oxidizing–sulphidizing environments
Authors: Tjong S. C. 
Published: May 2005

AbstractThe use of Fe–Mn–Al–C alloys in oxidizing–sulphidizing environments at elevated temperatures is considered. Applications of SEM, EDX mapping and x‐ray diffraction techniques to the microstructural characterization of the scale development on these alloys are reviewed. Combination of the electron microscope and the analytical techniques provides information concerning the morphology, elemental distribution, crystal structure and identification of phases in the scale. This information is of particular importance in the design and development of a corrosion‐resistant alloy. Application of the above techniques is described with examples from oxidation studies in air and corrosion studies in SO2–O2 gas mixtures with different sulphur partial pressures.
Current trends in the literature on x‐ray emission spectrometry
Authors: Van Grieken R. , Markowicz A. , Veny P. 
Published: May 2005

AbstractBased on a computerized literature search through Chemical Abstracts for the period 1968–89 and on a manual search through Analytical Abstracts for 1988, trends in the literature are discussed for x‐ray emission spectrometry in general, and for x‐ray fluorescence analysis, proton‐induced x‐ray emission and synchrotron‐induced x‐ray fluorescence analysis. Relative contributions are derived for articles dealing with various excitation and detection modes, with different application fields and from different countries. Special attention is paid toenvironmental applications of x‐ray emission spectrometry.
Matrix correction in x‐ray fluorescence analysis by the effective coefficient method
Authors: Broll Norbert , Caussin Pierre , Peter Markus 
Published: May 2005

AbstractUp till now, the well known effective coefficient method was used by referring to a single standard. The SFP (Siemens fundamental parameter) program additionally allows this method to be employed with several standards and to analyse samples containing an element that is not analysed. A modified algorithm, called the trace model, yields an improvement in the precision of the trace element analysis. The different variants are illustrated by practical applications.
Carbon Kα peak shift study using an electron probe microanalyzer with a vanadium–carbon multilayer pseudo‐crystal
Authors: Liang Long C. 
Published: May 2005

AbstractA study of carbon Kα peak shifts using an electron probe micronalyzer (EPMA) with a vanadium‐carbon multilayer pseudo‐crystal (2d = 96 Å) shows a distinct peak shift between diamond and graphite and two organic carbon phases (asphaltene and vitrinite). The peak shift reflecting the difference in carbon‐to‐carbon bonding types and structures shows that the carbon electron binding energy of diamond is higher than that of graphite, asphaltene and vitrinite. The relative electron binding energies of these phases obtained from the EPMA study were confirmed by ESCA (electron spectroscopy for chemical analysis) data.
Accurate description of surface ionization in electron probe microanalysis: An improved formulation
Authors: Merlet Claude 
Published: May 2005

AbstractA new analytical expression of the surface ionization Φ(0) is derived in terms of atomic number and overvoltage. This expression is obtained by means of an analytical description of the energy distribution of backscattered electrons. The Φ(0) data for Pt, W, Sb, InSb, Ni, Co and Mg have been measured using the tracer technique. The Φ(0) values obtained by using the new expression compare more favourably with experimental results, Monte Carlo simulation and backscattering data from the literature than those obtained with the previous analytical models.
High‐order multiple scattering contributions in x‐ray spectrometry
Authors: Sartori R. , Fernández J. E. 
Published: May 2005

AbstractMultiple scattering contributes important parts to the emission spectrum from thick targets excited with x‐ray photons. Both the continuous and discrete parts of the spectrum receive enhancement by multiple scattering. Recently, some expressions were deduced in the framework of transport theory allowing the computation of the second‐order chains of the Compton and Rayleigh effects. In this work those calculations were extended to the third and the fourth orders of multiple scattering by means of Monte Carlo simulation. Monte Carlo results were computed using full expressions for the angular kernels (i.e. scattering coefficients including atomic form factors). The second‐order Monte Carlo result was compared with the computation by deterministic means, showing close agreement except in the extreme of the Compton‐Compton spectrum. Higher orders are important for low‐Z elements but can be safely neglected in the medium‐Z range.
Characterization of environmental dusts by x‐ray fluorescence spectrometry using a micro bead presentation
Authors: Moore Lynne V. 
Published: May 2005

AbstractSmall dust samples of mass ca. 0.07 g are fused with a lithium fluoride–lithium tetraborate flux to yield a homogeneous micro bead. These beads are presented to a wavelength‐dispersive spectrometer and the composition of the sample derived from calibrations effected with international standards. Matrix corrections are calculated by an NBSGSC algorithm.
Monte Carlo simulation of conventional and synchrotron energy‐dispersive x‐ray spectrometers
Authors: Janssens K. , Vincze L. , Van Espen P. , Adams F. 
Published: May 2005

AbstractA number of examples of the use of a detailed Monte Carlo (MC) simulation program for EDXRF spectrometers is discussed. The MC code is employed to predict the complete spectral response of a polychromatic EDXRF spectrometer using different excitation conditions. With respect to quantification of steel samples in which significant enhancement and self‐absorption occur, the usefulness of the code in simulating spectra corresponding to calibration standards is demonstrated. An extension of the program that deals with simulating the interaction of polarized radiation with matter is used to estimate the analytical qualities of currently operating and future mono‐and polychromatic synchrotron radiation XRF spectrometers.