bluuebunny/crossref_metadata_2025_split huggingface dataset:
Some possibilities for the use of so‐called ‘differential’ correction equations in x‐ray fluorescence analysis
Authors: Kuczumow Andrzej 
Published: May 2005

AbstractIn connection with progress in the creation of differential and so‐called differential methods of concentration correction, work has been carried out on the ordering of equations. It has been shown that it is possible to create three principal, complete systems of so‐called differential concentration correction equations by (1) using the Claisse method, (2) using the method of function expansion in a Taylor series and (3) using a special method discussed in this paper. These equations can be used instead of the classical concentration correction methods. Moreover, it has been proved that the respective procedures can be used in the creation of expressions which are the analogues of classical intensity correction equations.
Theoretical derivation of fluorescent x‐ray intensities in x‐ray fluorescence spectrochemical analysis
Authors: Li‐Xing Zhang 
Published: May 2005

AbstractThe theoretical equations for primary, secondary and tertiary fluorescent x‐ray intensities have been given by Shiraiwa and Fujino. However, their derivation is unsatisfactory in some respects. In this paper these problems are discussed and a more correct derivation is given.
Electron ionization cross‐sections for K, L and M shells
Authors: Rez Peter 
Published: May 2005

AbstractThe total cross‐sections for ionization of K, L and M shells in various atoms have been calculated using first‐order perturbation theory and Hartree–Slater wave functions. For K shells, the hydrogenic wave functions have been used. The systematic changes across the Periodic Table are discussed and the results of a Bethe parametrization are also given.
Solvent extraction–microdroplet x‐ray fluorescence analyses of trace amounts of heavy metal ions
Authors: Murata Michihiro , Omatsu Masayuki , Mushimoto Syuji 
Published: May 2005

AbstractParts per billion amounts of heavy metal ions can be determined simultaneously by combining solvent extraction with microdroplet x‐ray fluorescence measurement. The use of diisobutyl ketone as a solvent for the extraction of heavy metal ions with sodium diethyldithiocarbamate is effective for improving detection limits in x‐ray analysis. A specially designed filter‐paper is used as a sample medium in the microdropler x‐ray fluorescence method and the volume of the droplets required for x‐rey measurements is only 20–100 m̈l. The detection limits of Mn, Fe, Co, Ni, Cu, Zn and Pb ions are 15, 16, 8, 8, 13, 13, 40 ppb, respectively, for a 100‐m̈l sample volume.
Monte Carlo simulation of the backscatter region in energy‐dispersive x‐ray fluorescence spectra of homogeneous multi‐element samples with an application to quantitative analysis
Authors: Arinç Faruk 
Published: May 2005

AbstractThe backscatter region of an energy‐dispersive x‐ray fluorescence spectrum obtained by radioisotope photon excitation of a homogeneous, multi‐element sample of any thickness is considered to be made up of a linear summation of several backscatter response spectra, each due to a constituent in the sample. A Monte Carlo computer program already developed for pure samples has been modified to generate these spectra and the results are compared with real spectra. The characteristic data used for each constituent in mixture and alloy samples, such as scattering cross‐sections and Compton profiles, are those of pure elements. As for chemical‐compound samples, an effective Compton profile is determined from a calibration graph and is used for all the constituent elements. It is shown that, for samples with unknown weight fractions, it is possible to generate the Ag Kα backscatter peaks dependent on such sample characteristics as density, thickness, approximate total cross‐section determined from another calibration graph at the scattered photon energy and effective Compton profile. The unknown weight fractions for all the constituents, including those with very low atomic numbers, are then calculated by using the computer‐simulated Ag Kα peaks for each constituent and a background spectrum as the standard library spectra of a linear least‐squares program. The advantages and drawbacks of such a qualitative analysis together with future improvements are discussed.
Melted sample (glass disk) ageing and its usability for x‐ray emission spectrometry
Authors: Novosel‐Radović V. J. , Maljković D. A. , Nenadić N. 
Published: May 2005

AbstractThe usability of glass disks prepared from blast furnace slag samples as a function of age in x‐ray emission spectrometry was investigated. Glass disks were prepared by melting sample and flux mixtures (Li2B4O7–Li2CO3–La2O3, 100: 10: 5) in the ratio 1: 100 at 1100°C for 30 min. The glass disks were examined by the ISIJ test. X‐ray spectrometry and scanning electron microscopy were applied directly after preparation and again after 6, 12 and 18 months. A change in the surface of the glass disk and a decrease in the Ca Kα, Si Kα and S Kα line intensities with time were observed.
Determination of the ash content of coal by multi‐element x‐ray fluorescence analysis
Authors: Dziunikowski Bohdan , Stochalski Aleksander 
Published: May 2005

AbstractA method for determining the ash content of coal by measuring the x‐ray fluorescence of Si, Al, Ca and Fe using a diffraction spectrometer is presented. The experiments were carried out on 72 samples of coal from different deposits. A mean standard deviation of the ash content of about 1. 65% was achieved.
Non‐destructive measurement of gas pressures in sealed halogen lamps by x‐ray spectrometry
Authors: Lublin P. , Pink F. , Persiani C. 
Published: May 2005

AbstractX‐ray spectrometry has been used to determine the pressure of krypton gas in high‐pressure halogen auto lamps. The method employs a standard diffraction tube, a special collimator and a solid‐state detector.
PDIDENT—a set of programs for powder diffraction phase identification
Authors: Goehner Raymond P. , Garbauskas Mary F. 
Published: May 2005

AbstractPDIDENT is a collection of interactive computer programs which have been developed as aids for qualitative phase analysis of x‐ray powder diffraction data. These FORTRAN IV programs are implemented on a DEC committee on Powder Diffraction Standards (JCPDS) data base is accessed by the programs along with user‐created data. The data base (sets 1–32) along with all cross‐index files requires 9 Mbytes of storage. The packing of the data base, use of cross‐index files and the algorithms and utility of the PDIDENT programs are described.
μ/ρ Algorithm valid for 1 keV ≤ E ≤ 50 keV and 11 ≤ Z ≤ 83
Authors: Wernisch J. , Pöhn C. , Hanke W. , Ebel H. 
Published: May 2005

AbstractMass absorption coefficients can be calculated by this algorithm with programmable pocket calculators giving a standard deviation of about 5% when compared with McMaster's tables.
Quantitative electron microprobe determination of oxygen in metal layers covered by surface oxide films
Authors: Willich P. , Obertop D. , Tolle H. J. 
Published: May 2005

AbstractA special electron microprobe data reduction procedure permits the determination of oxygen in vacuum‐deposited metal layers independent of the surface oxide layer, the mass thickness of which is simultaneously calculated. The method combines measurements of O Kα x‐rays at two values of the primary electron energy in the range 5–12.5 keV, which correspond to different depth distributions of x‐ray production. The measured data are evaluated by calibration curves derived from Gaussian Φ(ρz) depth distribution functions. Test analyses have been performed on amorphous metal layers with thicknesses of 0.5–1.5 μm. Typical concentrations of incorporated oxygen found ranged from 0.1 to 5 wt‐%. The influences of surface oxide films with mass thicknesses of 1–30 μg cm−2 were studied by annealing experiments in agreement with the results derived from oxygen depth profiles measured by secondary ion mass spectrometry.
Quantitative electron microprobe analysis without standard samples
Authors: Wernisch Johann 
Published: May 2005

AbstractThis review of the theory of pure element count rates measured by means of an electron microprobe analysis system with energy‐dispersive x‐ray detection defines the fundamental parameters needed for an analytical algorithm. Additionally, a presentation of these parameters by useful approximations is given. This is a basic requirement for the evaluation of theoretical expressions valid for characteristic x‐ray intensities of multielement samples. The derivation of these expressions is also given and from the results of numerous experiments it is concluded that (a) there is no systematic deviation of measured concentrations when compared with chemical analysis, (b) the quality expressed by absolute and relative errors of the analytical results is as good as that obtained by known methods that require standard samples, (c) the presented computer program, written for an HP 75C portable computer, gives the results of analysis within a calculation time of about 1 min and (d) the program is applicable to EDS and WDS both energy‐ and wavelength‐dispersive spectrometers and the range of application covers elements of Z ≥ 12.
Evaluation of an equation for bremsstrahlung background in electron‐probe X‐ray microanalysis of composite samples
Authors: Markowicz A. , Storms H. , Van Grieken R. 
Published: May 2005

AbstractA new equation for predicting the generated bremsstrahlung background intensity in electron‐probe x‐ray microanalysis has been verified experimentally. This equation is applicable to all bulk composite specimens and reduces to Kramers' equation for pure elements only. The experimental verification has been carried out for Al2O3, Fe2O3 and ZrO2 with radiation energies from 4.2 to 14.8 keV. The predicted bremsstrahlung intensities are in good agreement with the experimental data.
Fundamental algorithm between concentration and intensity in XRF analysis. 3—Experimental verification
Authors: Rousseau Richard M. , Bouchard Marcel 
Published: May 2005

AbstractAn algorithm, considered as a ‘fundamental algorithm,’ has been proposed for the precise correction of matrix effects, both absorption and enhancement, in the course of analysis of any complex system by x‐ray fluorescence. This new algorithm, relating concentration and intensity, is theoretically exact and includes influence coefficients derived by means of explicit equations expressed specifically in terms of fundamental parameters.Because of its theoretical characteristics, this algorithm should be adapted to the experimental reality by means of an appropriate calibration. Also, since influence coefficients depend on sample composition, the Claisse–Quintin equation is used at the outset to calculate a first approximation of the composition. Then, all influence coefficients suited to the sample are calculated, once only. Finally, a more refined estimate of the composition is calculated by applying an iterative process to the fundamental algorithm. In order to illustrate the practical application of this approach, a series of 28 NBS reference materials were analysed and the results are discussed.To carry out this experimental verification, a computer program has been developed for a minicomputer; the program was designed to minimize the operator interactions required to achieve easily any analysis. Thus, the long‐sought universal algorithm has finally become a reality, and its application is reduced to simple routine matters.
Study of the Kα emission spectrum of copper
Authors: Berger H. 
Published: May 2005

AbstractA simple model of the x‐ray Kα emission spectrum of copper metal has been proved to fit the experimental distribution curve of diffracted intensity fairly well, after correcting for profile distortion due to the spectrometer geometry and the diffraction process. Each Kα line can be described by a doublet of overlapping dispersion curves of different height and width. Although the physical relevance of the model is not clear at present, the simple analytical expression of the spectrum may be useful for some problems in x‐ray diffractometry.
Comparison of matrix effect correction and direct intensity–concentration relationship methods for major element analysis of geological materials by X‐ray fluorescence spectrometry
Authors: Guevara M. , Verma S. P. 
Published: May 2005

AbstractForty international geochemical reference samples were used to test two methods for data processing of intensity values and to obtain major element concentrations by XRF spectrometry. It was found that the direct intensity—concentration relationship method gives better results than the more commonly employed matrix correction technique. The major differences show up in MgO, Na2O and Al2O3. The method is precise to about ±1% and accurate to ±6% or better for most elements of geological interest.
A flux for the fusion of samples in analysis by X‐ray fluorescence spectrometry
Authors: Eddy B. T. , Balaes A. M. 
Published: May 2005

AbstractThe preparation of a pre‐fused flux for use in X‐ray fluorescence analysis is described. The flux is fused in graphite, quenched in water and then reduced to a fine powder in a polyurethane‐lined ball mill using tungsten carbide balls.
Unification of fundamental matrix correction methods in X‐ray fluorescence analysis. Arguments for a new binary coefficient approach
Authors: Tertian R. 
Published: May 2005

AbstractA comparative study of the main fundamental approaches for mathematical matrix correction in x‐ray fluorescence analysis is proposed. It shows that the fundamental parameter method (Criss and co‐workers) and the competing fundamental coefficient methods (Broll, Rousseau, Tertian) are in principle equivalent, then convergent as to their results, and suffer from the same inherent limitations. Authors differ as to the ways in which these shortcomings can be overcome or greatly reduced (essentially owing to standards), and these practical aspects are also discussed in detail.The paper recalls the many advances achieved with regard to the comprehension of influence coefficients (binary coefficients, effective multicomponent coefficients, interpretation of third element effects). As a consequence, it is shown that the utilization of accurate binary coefficients, combined with a single fundamental parameter calculation of the relative intensities for the sample, results in a very favourable algorithm. Theoretically equivalent to the former formulations, it is definitely simpler as regards the calculation scheme, and more general with regard to the scope of applications. It is best suited for the experimental control of instrumental factors.
A general way of solving matrix effect problems in elemental analysis by EDXRFS
Authors: Orlic I. , Makjanie J. , Raos D. , Valkovic V. 
Published: May 2005

AbstractInstead of using the complete set of fundamental parameters for solving matrix effects in quantitative energy‐dispersive x‐ray fluorescence (EDXRF) analysis, some of them, such as excitation and detection efficiency and the dependence of Compton and Rayleigh scattered intensities on sample composition, were determined from a set of standards such as chemical compounds and pure elements. In this way all fundamental parameters except mass absorption coefficients were removed from the calculation procedure, which results in a much simpler formalism. The computer program COREX based on this principle and described in this paper is relatively simple and can run even on small microcomputers, while the overall error can be kept in the range of a few percent if the calibration procedure and sample preparation were performed carefully.
Structural studies on heat‐treated pyrophyllite mineral by scanning electron microscopy
Authors: Amritphale S. S. , Patel M. 
Published: May 2005

AbstractPyrophyllite was heat treated up to 1000°C in the presence of fluxes such as Li2CO3, Na2CO3, K2CO3 and CaCO3 and the products were examined by scanning electron microscopy (SEM). It is shown that the surface morphology of the mineral varies with both temperature and flux. The dehydroxylation reaction in the mineral commences at 500°C and continues above 900°C. Dehydroxylated phases are observed even at 950‐1000°C. The formation of free Al2O3, cristobalite, mullite and other phases from pyrophyllite was detected by the SEM examination.
Soft x‐ray spectroscopic study of the MoxNi1 − x and Cu70Zn30 alloys
Authors: Lawniczak‐Jablonska K. , Leiro J. A. , Nikolaew L. I. 
Published: May 2005

AbstractThe x‐ray molybdenum M and nickel Lα1, 2 spectra were recorded for pure metals and several MoxNi100 − x alloys. The spectra for the pure metals were compared with the available theoretical density of states. The differences between the experimental and calculated data are presented after convolution with broadening functions. The modified p + f and d partial density of states (DOS) structure for molybdenum and nickel, respectively, is proposed. The changes in the DOS structure in alloys at the site of molybdenum and nickel atomas were estimated from experimental data. Broadening of the d band in nickel and the p + f band in molybdenum compared with the pure metal band was observed. These changes do not confirm the commonly used model of d‐band localization in metal alloys (e.g. in Cu70Zn30 alloy, which is also considered). A strong redistribution of valence band shape near the molybdenum atom after a change in crystal structure was also observed.
Absorption and fluorescence corrections of characteristic x‐rays from thin spheres
Authors: Zreiba Nuri A. , Kelly Thomas F. 
Published: May 2005

AbstractModels of absorption and fluorescence corrections for characteristic x‐rays emitted from electron‐transparent spheres are presented for a stationary point probe and for a rastered or flooding beam. In both models, the primary inonzation event and subsequent x‐ray emission are assumed to occur anywhere along the electron‐beam axis within the sphere. Multiple scattering effects are not taken into account but absorption of the fluorescence radiation is taken into account. The integrals involved in both correction models are solved numerically and the results are compared with previous models of thin‐foil, plane‐parallel specimens. An analytical solution for the fluorescence correction is obtained when the primary x‐ray generation is assumed to originate at the center of the sphere. Both corrections are found to be less severe for submicron spheres than the corresponding corrections for plane‐parallel specimens.
X‐Ray fluorescence analysis of zinc‐aluminium binary alloys by mathematical correction of matrix effects
Authors: Kutty K. V. G. , Rajagopalan S. , Mathews C. K. 
Published: May 2005

AbstractThe zinc contents of a series of zinc‐aluminium binary alloys were determined by wavelength‐dispersive x‐ray fluorescence spectrometry using very small samples. The Zn Kα radiation from the alloy undergoes an apparent enhancement due to the widely different absorption coefficients of zinc and aluminium for radiation close to the short‐wavelength side of the K absorption edge of zinc. This was corrected mathematically by using mass absorption coefficients from the literature. The method is comparable in accuracy to wet chemical analysis. The precision obtained is of the order of 0.25% relative at 6 atom‐% of zinc. The method of fitting the measured Zn Kα intensity to a non‐linear function of composition is also examined.
Software for energy‐dispersive X‐ray fluorescence
Authors: Rindby A. 
Published: May 2005

AbstractComputers have been used in quantitative x‐ray spectroscopy since the 1950s. The algorithms first used were usually based on non‐physical models and were dependent on a large number of calibration data from standard samples. In parallel with the development of the energy‐dispersive x‐ray fluorescence (EDXRF) technique, new software algorithms have been developed based on realistic physical models (e.g. fundamental parameter programs). A review of the basic properties of these programs is given and different methods for peak fitting are discussed. In order to handle and to obtain a survey of the large number of data generated by multi‐element methods such as EDXRF, various ‘post‐processing’ techniques have been developed, and examples of these kinds of techniques are given.
XRF procedures for analysis of standard reference materials
Authors: Tao Guang Yi , Zhang Zhong Yi , Ji An 
Published: May 2005

AbstractThe importance of Standard Reference Materials (SRMs) or Certified Reference Materials (CRMs) in quality assurance of measurements is widely accepted. SRMs and CRMs are frequently used in analytical chemistry for calibration, verification and evaluation of both analytical methods and instruments. The homogeneity, means of certification, stability and uncertainty of certified values for SRMs or CRMs are of particular interest. As one of the main techniques of elemental analysis, x‐ray fluorescence (XRF) analysis plays an important role in homogeneity tests and certification measurements for SRMs and CRMs. The XRF procedures for analysing Tibet Soil and Chinese Tea CRMs are presented as examples. The results obtained by XRF are in good agreement with the certified values or those from using other analytical techniques and from the different laboratories.
Absolute x‐ray fluorescence method for the determination of metal thicknesses by intensity ratio measurements
Authors: Vazquez C. , De Leyt D. V. , Riveros J. A. 
Published: May 2005

AbstractAn absolute method for the determination of the thickness of a metal film deposited on a metallic substrate is described. The method is based on the measurement of fluorescent intensity ratios for two lines from the substrate element. Titanium sheets covered with nickel layers of different thicknesses (between 3 and 22 μm) were employed to test the method. Intensity measurements were performed using different excitation modes and detection systems. Additionally, the proposed method can be employed to determine the density of the deposited material or the incident angle of primary radiation and take‐off angle if the deposited metal film thickness is known. The method can be applied by using the intensity ratios of two lines generated through electron vacancies in the same shell.
X‐ray emission studies on the (La1 − xBax)2CuO4 ± y system
Authors: Acharya B. S. , Rajeev  , Muralidhar J. 
Published: May 2005

AbstractX‐ray emission spectroscopy was used to establish the valency of Cu in the superconducting (La1‐xBax)2CuO4±y (LBCO) system. Samples were prepared by both solid‐state diffusion and coprecipitation methods. It was observed that diffusion is faster and mixing is more intimate in the coprecipitated sample. A definite shift in the Cu K emission was also observed in samples such as CuO, La2CuO4 and LBCO. It was observed that the valency of copper in the LBCO system is equal to or greater than 2. Further, Ba has been found to play a major role in the emission process. The La emission spectra remained the same for all the samples studied. SEM and XRD studies indicated the presence of a two‐phase structure of the compound.