bluuebunny/crossref_metadata_2025 huggingface dataset:
A versatile, compact system for X‐ray fluorescence analysis
Authors: Ricci Enzo , Dunn H. W.
Published: May 2005

We have developed a highly versatile, energy‐dispersive system for X‐ray fluorescence (XRF) analysis. Excitation may be achieved both by a Ag anode tube and by isotopic sources of 241Am or 55Fe. Radiation from the former may be either filtered and collimated, or monochromatized by a pyrolytic graphite cylindrical monochromator with further filtration through Pd foils. The system is currently being used both for quantitative fundamental‐parameter (absolute) analysis and for standard‐based determinations. A variety of mounts allows quantitative work on solid thick or thin samples, liquids, and specimens evaporated on 6.2 μm thick Mylar. Aside from single‐sample operation, a 90 position sample changer allows multi‐sample analysis, with great gain in work efficiency. The latter is automatically controlled by a PDP 11/05 computer, which also calculates results from the raw data from a Tracor Northern NS 880 energy‐dispersive system. Accuracies for analyses of steels (percent level) are ∼5%, while trace Zr/Hf analysis can be performed with 10–15% error; sensitivity for the latter is 0.4–1.0 ppm.
X‐Ray K absorption edge studies of cobalt in complexes with nitrogen based aromatic ligands
Authors: Kumar A. , Nigam A. N. , Srivastava B. D.
Published: May 2005

The X‐ray K absorption edges of cobalt in some complexes with nitrogen based ligands [α‐Co(py)2Cl2, Co(py)2Br2, Co(bipy)Br2 and Co(phen)Br2] have been recorded using a 40 cm bent crystal spectrogrph. The absorption edge shift and edge width have been discussed in terms of effective nuclear charge, molecular symmetry and the nature of the ligand. The radii of the first coordination sphere have been calculated using Levy's method and a correlation suggested.
An evaluation of X‐ray tube spectra for quantitative X‐ray fluorescence analysis
Authors: Murata Michihiro , Shibahara Hiroyasu
Published: May 2005

Full spectra including both the continuous and characteristic lines from X‐ray tubes are evaluated in a simple way. The penetrating depth of an electron in the target of the X‐ray tube is determined and the Kramers' spectrum corrected for the effects of absorption. The characteristic lines are evaluated from a relation between direct electron excitation and indirect excitation by continuous X‐rays. The calculated spectra from W and Cu X‐ray tubes are given and their usefulness is confirmed by analysing some typical samples including Ag/Pd and Cu/Zn alloys and BaO/TiO2 mixed oxides.
Automatic qualitative identification of unexpected elements in quantitative energy‐dispersive X‐ray spectrometry
Authors: Leyden D. F. , Bodnar W. B. , Lemons W.
Published: May 2005

A combination of deconvolution, spectra subtraction and elemental identification routimes has been made to alert the energy‐dispersive X‐ray spectrometrist to elements present in the sample but not included in the fit.
Comparison of the Japanese industrial standard and α‐correction methods for X‐ray fluorescence analysis of steels
Authors: Ito Minao , Sato Shoki , Narita Masanao
Published: May 2005

In the X‐ray fluorescence analysis of steels, a correction method is usually used to eliminate absorption‐enhancement effects. It is a desirable that the correction factors should be common to all experimental conditions and therefore the fluorescent X‐ray intensity should be specified in a common unit. For this purpose, the JIS method converts the fluorescent X‐ray intensity into a tentative analytical value from the calibration curve of binary alloys, while the α‐correction methods employs the ratio of the intensity of an analytical sample to that of a pure substance for the fluorescent X‐ray intensity. In this report a detailed comparison of these methods is made, and the good and bad points of the JIS method discussed.
A computer program to evaluate a counting loss correction constant in XRF analysis
Authors: Stecher Ole
Published: May 2005

Different sources of counting loss are described and the relation Rt = Rm exp (Rt τ) is considered valid for most commercial XRF counting devices. Based on a series of Kα/Kβ measurements and an initial estimate of the Rt (Kα)/Rt (Kβ) value, corresponding τ values can be computed. If the chosen Rt (Kα)/Rt (Kβ) value differs from the correct one, the τ values will not be identical. The computer program iterates the Rt (Kα)/Rt (Kβ) value until the τ values have reached a desired level of agreement. The program is given together with a worked example of the calculation.
Analyse Automatique des Spectres de Rayons‐X par Dépouillement Spectral
Authors: Lecomte R. , Landsberger S. , Paradis P. , Monaro S. , Desaulniers G.
Published: May 2005

Une méthode complétement automatisée de dépouillement des spectres de rayons‐X ne faisant appel à aucune description analytique de la forme des pics et du bruit de fond, est adaptée à l'analyse de la région à basse énergie du spectre. La décomposition du spectre d'un échantillon en ses composantes indépendantes est réalisée à l'aide d'une librairie compléte de spectres standards incluant un bruit de fond témoin. Le principe de calcul suggéré permet de tenir compte des sources de contamination des échantillons de facon simple et originale.
Fast X‐ray imaging using a position sensitive proportional counter
Authors: Gurker N. , Zeiner K.
Published: May 2005

An X‐ray imaging method based on image reconstruction from projections has been established by analogy to medical computed tomography (CT). Where CT uses transmission, X‐ray imaging (X‐ray macroscopy, XMA) uses reflection. Using an energy‐dispersive Si(Li) detector and performing translation and rotation steps of the sample across the line focused X‐ray beam separately and sequentially, X‐ray imaging suffers from long data acquisition times (several hours). A position sensitive proportional counter (PSPC) has been used to generate a complete translation profile (projection) simultaneously. The sample is illuminated by an X‐ray cone and the reflected fluorescence intensity distribution imaged on to the PSPC by an imaging slit. Scanning movements are reduced to sample rotations; sample translation is not required. Preliminary experiments have shown that data acquisition times are shortened by a factor of ten. An experimental arrangement for fast tomographic imaging, results and some problems arising from using a PSPC are discussed. Finally, a second direct imaging experiment, equivalent to scanning the sample across a point‐focused X‐ray beam, is introduced.
Direct determination of trace elements in coal: Wavelength‐dispersive X‐ray spectrometry with matrix correction using compton scattered radiation
Authors: Mills John C. , Turner K. E. , Roller P. W. , Belcher C. B.
Published: May 2005

An X‐ray flourescence method is described for the direct determination, without pretreatment, of up to 55 trace elements in coal and coal‐derived materials. A single assay specimen is prepared by blending finely crushed sample with a binder and briquetting. Calibration is effected by a suite of synthetic calibration standards prepared from spectrographically pure materials blended into graphite. Variations in ash and sulphur content required matrix absorption corrections to analyte and background intensities, which were achieved by use of relationships with the measured Compton scattered radiation. Prior knowledge of or assumptions concerning the composition of the coal are not required. Accurate results are presented for three NBS coal standard reference materials. Certain elements (including TI, Hg, Te, In, Cd, Ag and most rare earths) are normally present in coal at levels below the detection capability of the described method and require quantification by alternative techniques.
The application of energy‐dispersive X‐ray fluorescence and the fundamental parameter approach to the analysis of NiFeCr alloys
Authors: Christensen Leif Højslet , Pind Niels
Published: May 2005

The fundamental parameter approach has been applied to NiFeCr alloys using an energy‐dispersive X‐ray fluorescence spectrometer employing secondary target excitation. The relative distributions of primary, secondary and tertiary fluorescence for these alloys and some of the assumptions inherent in the fundamental parameter approach are discussed both on a theoretical and an experimental basis. For a series of hypothetical NiFeCr alloys, our theoretical calculations show that the tertiary fluorescence contribution to the Cr intensity varies from 0.1 to 7.25% dependent on composition and on excitation energy. Furthermore, a general calibration procedure independent of the sample matrix and the kV, mA and collimator settings is outlined. The analysis results obtained for six reference alloys proved to be accurate within 5% for most elements. The results obtained with and without tertiary fluorescence included in the model deviate 2–5% only. This is partly due to a matrix absorption correction compensation in the latter case.
Maximum a posteriori technique applied to energy‐dispersive X‐ray fluorescence spectra
Authors: Schwalbe L. A. , Trussell H. J.
Published: May 2005

We review the maximum a posteriori formalism and apply the technique to the deconvolution problem of energy‐dispsersive X‐ray fluorescence spectra. An exact closed‐from expression for the a priori probability density is derived from physical considerations. A single CuZn spectrum is taken to illustrate the effects of various assumed forms for the restored spectrum probability distributions. Our best results follow from calculations that involve a self‐consistency condition. These restorations are contained within the set of maximum likelihood solutions.
Comparison of different methods for the matrix correction in X‐ray spectrometry
Authors: Plesch R.
Published: May 2005

In order to empirically test five mathematical equations of matrix correction, the theoretical X‐ray intensities of the ternary system CrFeNi were used. The smallest analysis error was obtained from a complicated equation which was derived from theory. Simplification of this equation resulted in the equation developed by Rasberry and Heinrich which proved to be almost as effective and is thus to be preferred in practice because of its simpler structure. A further simplification, dispensing with a special correction for secondary fluorescence, led to a greatly increased analysis error. As expected, using the matrix element intensities instead of their concentrations resulted in larger analysis errors. Special consideration of the secondary fluorescence did not yield a better result. These results agree qualitatively well with the results obtained by Stankiewicz and Sanner which were obtained by means of the analysis of synthetic oxide standards.
Identification of single fibres by X‐ray diffraction in forensic analysis
Authors: Lynch B. J. , Kerrigan G. C.
Published: May 2005

A method of identifying small samples of fibres by X‐ray powder diffraction is described, which is ideally suited to forensic analysis. Being non‐destructive it can be used to indicate the most suitable solvent for further more complete analytical methods.
Double line Bragg reflection technique in energy dispersive X‐ray diffractometry
Authors: Mantler M.
Published: May 2005

The double line Bragg reflection technique allows phase transition studies with a time resolution of 0.2 s. The Kα and Kβ emission lines from the X‐ray tube are recorded simultaneously in an energy‐dispersive detector system. Both lines satisfy Bragg's equation for a different phase in the specimen. The latitude of parameter variations and the probability for the required parameter match are discussed on the basis of a specimen transparency model.
Energy dispersive x‐ray diffractometry: 2. Phase transformations at elevated temperatures
Authors: Mantler M.
Published: May 2005

Phase transformation studies as well as the determination of linear expansion coefficients are used to show characteristics, accuracy and methods of data evaluation in energy dispersive x‐ray diffractometry. A high temperature chamber was modified to withstand temperatures up to 2300°C with fixed angle geometry. Observation of phase transformations in time frames of 10s was possible. In addition, error analyses are made and a method of comparing intensities from angular dispersion to energy dispersive lines is presented.
Rapid preparation of robust pressed powder briquettes containing a styrene and wax mixture as binder
Authors: van Zyl C.
Published: May 2005

The binder is composed of nine parts (by mass) styrene copolymer and one part wax. Both ingredients are marketed under brand names and are available as 10 μm powders, which can be conveniently blended in bulk. Exceptionally robust briquettes containing 10% binder have been made from a great variety of sample types, including metal powders, ion exchange resins, coal, charcoal, graphite, ash, vegetable matter and geological materials. Normally the sample and binder are milled together in a swing mill and milling behaviour is not adversely affected. The briquettes are not affected by vacuum, radiation or age. Erratic milling efficiency of the six‐vessel swing mills used and modifications to overcome the problem are described. For the most satisfactory ejection of a briquette, the cylinder wall of the die should taper slightly outwards near the ejecting end. A pressure of at least 0.04 MPa is recommended to ensure maximum x‐ray fluorescence intensity, but higher pressures improve briquette strength. In the above‐mentioned laboratory 0.23 MPa is normally used. The time the briquette is held under full load is not important. The simplicity of the method makes it possible to mill and press more than 1000 briquettes per day. Binder cost is approximately 3 cents per gram.
A comparison of two equations used as calibration curves for ternary samples in x‐ray fluorescence spectrometry
Authors: Mainardi R. T. , Rubio M. , Meda J.
Published: May 2005

It is well known that calibration curves in x‐ray fluorescence spectrometry offer to the analyst different alternatives to fit measured data. We have set out to compare two well‐known algorithms, those of Rasberry and Heinrich (R–H) and Lachance and Traill modified by Claisse and Quintin (LTCQ), with computer generated data using the fundamental parameter method. It is seen that both work reasonable well for binary samples, but in ternary samples deviations from reference points are larger for R–H than for LTCQ. We conclude from this study that ternary effects in R–H are not accounted for adequately, since only binary coefficients are needed to determine a calibration curve for any ternary as well as any multicomponent sample. In LTCQ, inclusion of an additional coefficient determined from a ternary standard suffices to improve considerably the degree of fitting to reference.
Energies et Probabilités de Transition des Raies XL du Neptunium
Authors: Maria H. , Dalmasso J. , Ardisson G. , Hachem A.
Published: May 2005

Le spectre xL du Np accompagnant la désintégration de 241Am a été soigneusement examiné avec des détecteurs HPGe. Les valeurs des énergies des raies principales sont en bon accord avec les résultats déduits du travail de Bearden, sauf pour les raies Lα1 et Lβ2,15 qui dépassent les valeurs théoriques de 8 et 22 eV respectivement. Les intensités des différentes raies s'accordent bien avec les résultats antérieurs; les raies β9, β10, γ11, γ13, t et s sont caractérisées pour la première fois dans le Np (Z = 93). Les rapports de probabilité dans les sous‐couches L sont cohérents avec les calculs Hartree–Fock–Slater de Scofield.
X‐ray fluorescence analysis of natural phosphates
Authors: Waňková J. , Knob B. , Moudrý F. , Kuba M.
Published: May 2005

An x‐ray fluorescence method was developed for the determination of P and Ca in raw phosphates. A modified mathematical method suggested by Lucas‐Tooth and Pyne was used to correct for matrix effects. The constants and influence coefficients in the algorithm were assessed using a set of 20 standard samples whose composition was determined by chemical analysis. The correspondence of P and Ca concentrations, as determined by the x‐ray method in samples from different deposits all over the world, with the results of chemical analysis can be characterized by the coefficient of variation v of the differences between the two methods. The value of v was 1.2% and 1.8% for P and Ca, respectively. The effects of a preliminary treatment of phosphates by calcination and of reducing the number of phosphate rock deposits, the samples of which are analysed, on the value of v are discussed.
Minimum flux fusion processing of iron ores for XRF analysis
Authors: Feret F.
Published: May 2005

The effects of particles size, sample‐to‐flux ratio, fusion temperature and fusion period on the speed of lattice decomposition of three different iron ores were tested. Russian Krivoj Rog (hematite), Jugok concentrate (magnetite) and Polish siderite were used for structural investigations. In order to estimate the degree of crystallographic destruction of the material, x‐ray diffractometry was used. Contrary to the usual large dilution associated with fusion, experiments with minimum flux contribution were carried out. The heat treatment (fusion) of samples was performed in graphite crucibles. The minimum flux technique was compared with dilution fusion (Pt‐Au crucibles) on 32 iron ore standards.
Self‐absorption of As, Se and Br for their Kβ2 and Kβ1,3 radiations and its effect on intensity ratio measurements (chemical state analyses of As, Se and Br by X‐Ray Method. 3)
Authors: Iwatsuki Masaaki , Fukasawa Tsutomu
Published: May 2005

A dependence of the observed Kβ2/Kβ1,3 intensity ratios of As, Se and Br on their concentrations in measured samples was found in a study of the use of these ratios in chemical state analysis. This paper includes the experiments and discussion on this concentration effect, which is caused by the large difference between the self‐absorption coefficients of each element for its Kβ2 and Kβ1,3 radiations. An x‐ray spectrometer was used for the measurements of the intensity ratios and absorption coefficients. Since the Kβ2 radiation of each element has a wavelength shorter than the Kβ1,3 radiation and longer than the K absorption edge, the self‐adsorption coefficient of the Kβ2 radiation was presupposed to be smaller than that of the Kβ1,3 radiation. The results of experiments, however, were contrary to the supposition. The observed self‐absorption coefficients of these elements for their Kβ2 radiations were 1.4–2.2 times those of their Kβ1,3 radiations, depending on the chemical states of the elements as absorbers or x‐ray emitters. These values gave a solution to the concentration effect. The correction of the effect allows the inherent intensity ratios to be determined which may then be used for chemical state analysis.
A semi‐empirical method for quantitative XRF analysis of thick samples
Authors: Govil R. , Kataria S. K.
Published: May 2005

A simple semi‐empirical procedure for the determination of elemental concentration in light element matrices is proposed. The method consists of taking x‐ray fluorescence spectral measurements at several orientations of the thick planar samples with a standard x‐ray fluorescence set‐up consisting of a low power x‐ray tube and a Si(Li) x‐ray spectrometer. The measured intensities are then extrapolated to zero effective thickness for the fluorescent x‐rays. In the following we have carried out the extrapolation procedure for the ratios of the Compton scattered Mo Kα x‐rays to the fluorescent x‐rays which provides the direct determination of the elements in p.p.m. units with respect to the light matrix.
The Cu Kα1,2 spectrum as measured with a curved‐crystal spectrometer
Authors: Bremer J. , Johnsen T. , Sørum H.
Published: May 2005

An experimental study of the fine structure of the electron excited Cu Kα1,2 doublet in the energy range 20‐40 ke V is presented. The spectra are different from earlier published ones in the sense that both the intensity and the resolution are high. A convex‐crystal setting of the spectrometer is discussed. It is pointed out that when using a point source in association with a convex crystal the broadening due to the curvature of the planes vanishes. The high intensity enables one to unambigiously introduce two Lorentzians. The characteristic profile and location of the difference between the experimental data points and the fits show that the asymmetry of the Cu Ka1 and Kα2 lines most probably is due to the radiative Auger mechanism K‐LM.
Determination of S, Cl and F in silicate rocks by X‐ray fluorescence analyses
Authors: Leoni L. , Menichini M. , Saitta M.
Published: May 2005

X‐ray fluorescence analyses of briquetted rock samples for S, Cl and F were carried out utilizing experimental coefficients to correct matrix effects. Data on thirty‐two international standards are reported.
A formed filter paper medium for microdroplet analyses of liquid samples by X‐ray fluorescence spectrometry
Authors: Murata Michihiro , Murokado Kenichi
Published: May 2005

A new type of a formed filter paper is proposed as a sample medium for a microdroplet analysis by x‐ray fluorescence spectrometry. It has a circular center part, separated by a narrow circular groove from its edge, and four, paraffined, supporting bridges. It can thus keep a spot area constant when a liquid sample drops at the center part. After dropping the liquid sample, the paper is dried and used for the x‐ray measurement. It can be stored for years without any chemical change. This formed filter paper is effective in improving the linearity range of a calibration curve and the precision of a fluorescent x‐ray measurement as compared with a non‐formed filter paper. The sample volume required is only 20 to 100 μ1 and therefore microscale analysis of the liquid sample is allowable.
Sample analysis using gamma ray induced fluorescent x‐ray emission
Authors: Sood B. S. , Allawadhi K. L. , Gandhi R. , Batra O. P. , Singh N.
Published: May 2005

A non‐destructive method for the analysis of materials using gamma ray‐induced fluorescent x‐ray emission has been developed. In this method, special preparation of very thin samples in which the absorption of the incident gamma rays and the emitted fluorescent x‐rays is negligible, is not needed, and the absorption correction is determined experimentally. A suitable choice of the incident gamma ray energies is made to minimise enhancement effects through selective photoionization of the elements in the sample. The method is applied to the analysis of a typical sample of the soldering material using 279 keV and 59.5 keV gamma rays from 203Hg and 241Am radioactive sources respectively. The results of the analysis are found to agree well with those obtained from the chemical analysis.
The estimated binary calibration curve method in the JIS x‐ray fluorescence analysis of steels and standard samples necessary for the method
Authors: Ito M. , Sato S. , Narita M.
Published: May 2005

In the Japanese Industrial Standard for the x‐ray fluorescence analysis of steels, the ‘estimated binary calibration curve’ method has been adopted. In this method, the calibration curve for the binary system, consisting of an analyte and the principal constituent elements is estimated and derived by using multicomponent standard samples. The measured x‐ray intensity is first converted into a tentative analytical value from this calibration curve, and then the analytical result is derived from this tentative value using the correction procedure. In this paper, some methods and standard samples of making the estimated binary calibration curve are compared and discussed, also, the characteristics of the JIS method are described.
Some possibilities for the use of so‐called ‘differential’ correction equations in x‐ray fluorescence analysis
Authors: Kuczumow Andrzej
Published: May 2005

In 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

The 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

The 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

Parts 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

The 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

The 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

A 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

X‐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

PDIDENT 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

Mass 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

A 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

This 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

A 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

An 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

A 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

Forty 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

The 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

A 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

Instead 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

Pyrophyllite 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

The 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

Models 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

The 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

Computers 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

The 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

An 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

X‐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.
Intensity and distribution of background x‐rays in wavelength‐dispersive spectrometry
Authors: Arai Tomoya
Published: May 2005

Extensive studies of the components and distribution which govern background x‐ray intensity in the short wavelength region of wavelength‐dispersive spectrometry have been made. The theoretical calculations account for the contribution of coherent scattering (including anomalous dispersion factors), Compton scattering and absorption effects. For the precise comparison between the calculated and experimentally measured intensities, coherent and Compton scattered intensities of Rh Kα and Rh Kβ emitted from a rhodium‐target x‐ray tube were investigated with respect to different kinds of specimens. From the differences in the calculated and measured intensities, the intensity tailing of the large peak of the major components was found to be the Compton scattering of fluorescent x‐rays. A theoretical expression for calculating the magnitude of the background x‐ray intensity using an appropriately selected standard sample is described. The application of Co Kα x‐rays interferred by Fe Kβ x‐rays and the small intensity change in background x‐rays for the trace element analysis of steel samples are discussed.