bluuebunny/crossref_metadata_2025 huggingface dataset:
Dilution method in quantitative X‐ray diffraction analysis
Authors: Clark N. H. , Preston R. J.
Published: May 2005

The theory of the single dilution and double dilution methods for quantitative X‐ray diffraction analysis is presented, and verified experimentally for the analysis of silica in a set of seven synthetic standards. Dilution methods are a new concept in diffraction analysis, and show advantages over other methods.
Ein Beitrag zur quantitativen Elektronen‐strahlmikroanalyse von Phasen in polierten Anschliffen von Silikatproben mit dem Raster‐Elektronemikroskop und energie‐dispersiver Messung der Röntgenstrahlung
Authors: Brandit M. P. , Blum F.
Published: May 2005

In diesem Artikel wird als Beitrag zur Elektronenstrahlmikroanalyse eine quantitaive röntgenographische Analyse von Phasen in polierten Anschliffen von Silikatproben beschrieben. Für die energiedispersive Messung der Röntgenstrahlung ist das Raster Elektronenmikrosk op mit einem Halbleitermessplatz und für Die Bilderzeugung mit einem Halbeitermessplatz und fü die Genauigkeit der Anlage und die damit erreichbare Nachweisgrenze werden bestimmt. Die Berechung der Konzentration wied nach einer von Salter vorgeschlagenen vorschrift mit Hilfe von binären Oxidsystemen und renien Oxiden als Standardproben berechnet. Als analytisches Bisipiel für die Elektronenstrahlmikroanalyse wurde ein Zementklinker gewählt.
Quantitative analysis using the absorption of white X‐ray radiation
Authors: Kähkönen H. , Suhonen P. , Yli‐Penttilä M.
Published: May 2005

The absorption of continuous radiation was used in X‐ray absorption analysis. The entire spectrum was measured simultaneously by using a solid state detector and a multi‐channel pulse height analyser. The analysis of the spectra was performed via a method, where only the energy spectrum but not the intensity of the primary beam need be known.
X‐ray fluorescence spectrometry on variable thin deposits of powdered materials
Authors: Frigieri Paolo , Trucco Renato
Published: May 2005

This work is aimed at providing a direct analytical method for powdered materials collected on cellulose filters. The origin and composition of these materials may be very different. The analytical technique employed was X‐ray fluorescence spectrometry without preliminary treatment of samples.

It is known that different thickness of thin deposits, due for example to different sampling condition, cause some difficulties on the correct accomplishment of the analysis. To eliminate this drawback the basic principles characterising the behaviour of X‐ray penetration in the matter, were developed, thus leading to some equations, applicable to the analysis of the following kinds of samples: (a) sample of infinite thickness for X‐ray penetration; (b) sample of finite thickness below the critical value; (c) sample of infinite thickness placed over the sample of finite thickness.

The equation relating to case (c) was then applied to the analysis of powdered materials collected on cellulose filters.

A suitable plate of a selected metal was placed over the sample, and the fluorescence radiations intensity values of the element to be analysed were recorded together with the intensity of the radiation emitted by the plate.

By substituting some terms of the above mentioned equation with experimental data, X‐ray intensity values were corrected, and then independent measurements were performed on the sample thickness.

This work described both the theoretical part and the experimental procedures with results showing the method's reliability.
X‐ray fluorescence analysis of powder pellets utilizing a small quantity of material
Authors: Leoni L. , Saitta M.
Published: May 2005

The amount of material usually required for X‐ray fluorescene analysis of briquetted rock powders is of the order of 2 to 3 g. By reducing the diameter of the pellets and the cross‐section of the incident X‐ray beam, it is possible to analyse a small quantity of material (about 40 mg) reliably. The results obtained from the analysis of about 40 mg of powder for the major components (MgO, Al2O33, SiO2, P2O5, K2O, CaO, TiO2, MnO, Fe2O3) and for 12 trace elements (Cr, Ni, Cu, Zn, Ga, Rb, Sr, Zr, La, Ce, Ba, Pb) in 6 standard samples of rocks (US Geological Survey Standards: G‐2, GSP‐1, AGV‐1, BCR‐1, DTS‐1 and PCC‐1) are reported. These data are compared with those obtained from standard pellets and from literature values.
Zur experimentellen Bestimmung von Massen‐schwächungskoeffizienton mittels Röntgen‐fluoreszenz und variabler Strahlengeometrie
Authors: Mantler M.
Published: May 2005

Mit Hife eines speziell für variable Strahlengeometrie adaptiertenten Röntgenspektrometers wurden Massenschwaächungskoeffizienten nach den Methoden der Schicht‐und Trägerfluoreszez bestimmt. Besonderer Vorteil ist, daß Aufdampfschichten in experimentell guünstigen Schihtdickenbereichen als proben verwendet werden koönnen. Die Methode bietet sich an, wenn Folicn für die konventionellen Absorbermessungen nicht ausreichend dü hergestellt werden können.
Kβ/Kα intensity ratios for elements of atomic number 20 to 30
Authors: Smith D. G. W. , Reed S. J. B. , Ware N. G.
Published: May 2005

Twenty‐five new measurements of Kβ/Kα X‐ray intensity ratios for elements in the atomic number range 20 to 30 confirm other recent evidence that the variation with atomic number in this region is much less than previously thought, but there is still some disagreement for atomic numbers above 27. A table of recommended values is given.
Die Korrektur der Probentransparenz in der Röntgenspektralanalyse
Authors: Weber Kurt
Published: May 2005

Die Strahlendurchlässigkeit Von Proben mit vormiegend leichten Elementen (z.B.wässrige Lösungen, Schlacken, Mineralund Gesteinsproben) führt zu Fluoreszenzatrahlungsverlusten, die unter Berücksichtingung der Strahlengeometric berechnet Werden und deren praktische Messung beschrieben wird. Die Ergebnisse zeigen, dass die erforderlichen Korrekturen im Bereich der K‐Spektren etwa beim Element Rb (Z=37)mit maximal einigen %einsetzen und zum Ba (Z=56) hin rasch ansteigen, Durch Interpolation lassen sich alle in Frage kommenden Elemente an Hand einer einzigen Korrekturtafel erfassen, Die Durchfuhrung der Korrektur verlangt die Kenntnis des Matrixfaktors und des Probengewichtes und des Probengewichtes und erfordert keine zäsatzliche präparation.
Eichprobenfreie Bestimmung der Massenbelegung ebener dünner Schichten mit einem energiedispersiven Spektrometer
Authors: Ebel H. , Fuchs G. , Gurker N. , Wernisch J.
Published: May 2005

Die röntgnfluoreszenzanalytiche Bestimmung der Massenbelegung dünner Schichten ist literaturbekannt. Diese Methoden bauen zumeist auf einem Vergleich mit Proben difinierter. Massenbelegung auf. Es wird von der Theorie her gezeit, wie eine eichprobenfreie Messung möglich ist. Neben einer Abschätzung der mit dieser Methode verbundenen Fehler Werden die Messungen mit einem energiedispersiven Spektrometer und die rechnerische Auswertung behandelt.
The shape of the continuous X‐ray spectrum and background corrections for energy‐dispersive electron microprobe analysis
Authors: Reed S. J. B.
Published: May 2005

The shape of the continuous spectrum between 0.5 and 10 keV generated by 10 to 25 keV electrons has been calculated. It is shown that Kramers' law underestimates the intensity generated at low X‐ray energies. However, this is partially compensated by the greater absorption suffered by continuum X‐rays compared with characteristic X‐rays, which is demonstrated by comparing the depth distributions derived from Monte‐Carlo calculations. Refinement of the background correction in energy‐dispersive microprobe analysis in the light of these results is desirable, though for most purposes the method based on Kramers' law corrected for absorption by the conventional means used for characteristic radiation is adequate.
Application of the method of variable take‐off angle to rapid quantitative XRFA with energy dispersive systems
Authors: Ebel H. , Drabseh S.
Published: May 2005

One way carrying out quantitative X‐ray fluorescence analysis with fundamental parameters is the method of variable take‐off angle. At angles nearly parallel to the sample surface, the equations can be solved more easily and no knowledge of the white spectrum and μ(λ) is needed. For practical application, in order to get a well defined geometry, we used a diffraction goniometer, an X‐ray tube with Mo target and an energy dispersive detector, followed by a multichannel analyser. After calibrating the system, all information essential for a quantitative analysis was obtained from a single measurement. The validity of the final equations was verified by experiments with different alloys, consisting of two, three and four components.
X‐ray fluorescence analysis of corrosion products of steel
Authors: Blomqvist P. O.
Published: May 2005

An X‐ray method for the analysis of thin oxide films on steels has been developed. The oxide layer is first stripped off by the action of bromine in methanol in an inert atmosphere. It is then dissolved and a small amount of the solution is allowd to evaporate on a filter paper impregnated with disodium carbonate. The matrix effects are thus negligible, which can be seen from the standard curves obtained from synthetic oxides in this way. From the standard curves the precision has been estimated to be about ± 5%. The method has been used to analyse oxide layers formed on four different steels oxidized at high temperatures.
Chemical state analysis of vanadium by high resolution X‐ray spectroscopy
Authors: Gohshi Y. , Nakamura T. , Yoshimura M.
Published: May 2005

The chemical shift of V Kβ1, 3 and width of V Kα1 were measured with a two crystal X‐Ray spectrometer. It was found that V Kβ1, 3 shift and V Kα1width can be utilized for identification of the vanadium oxidation state. Applications to vanadium containing catalysts and several perovskite structure compounds are discussed.
Emission de rayonnement X par suite de bombardement de protons
Authors: Bodart F. , Wilk S. , Deconninck G.
Published: May 2005

Les sections efficaces de production de rayonnement X émis par suite de bombardement de protons de moyenne énergie (0,4 à 2,3 MeV) sont mesurées avec un détecteur Si(Li) à haute résolution. La séries des corps suivants a été étudiée: Ti, V, Cr, Mn, Fe, Co, Ni, Cu. Les courbes d'ionisation sont déduites et le résultat est comparé avec des calculs obtenus à partir du modèle théorique de l'approximation de Born par ondes planes et du modèle semi‐classique. La comparasion fait apparaître la faiblesse des deux modèles dans cette région d'énergie. Des écarts importants apparaissent entre les rapports d'intensité Kα et Kβ provenant de différentes sources.
Calcul théorique des effets interéléments dans le cas des éléments légers. Influence de la dilution
Authors: le Sage R. Vié
Published: May 2005

Nous avons calculé les effets interéléments (absorption, renforcement et effets croisés) pour les mélanges d'oxydes des éléments Ti, Ca, K, S, P, Si, Al, Mg et Na en supposant une excitation monochromatique due à la radiation CrKα, et nous avons établi un parallèle entre (1) les mélanges compacts et (2) les solutions solides des mêmes oxydes dissous dans les fondants usuels, B4O7Li2 et B4O7Na2. On constate que les effets mutuels sont tres prononcés dans le premier cas, étant tout à fait comparables à ceux connus pour les alliages métalliques, tandis qu'ils sont plus ou moins atténués, comme on s'y attend, pour les systèmes dilués correspondants. On décrit le mecanisme de cette atténuation, de même que les simplifications apportées sur le plan des corrections matricielles.
Quantitative X‐ray energy dispersive analysis with the transmission electron microscope
Authors: Geiss R. H. , Huang T. C.
Published: May 2005

A Comprehensive study of the interfacing of an X‐ray energy dispersive spectrometer to a transmission electron microscope is presented. Optimum detector location, sample tilt, collimation and accelerating voltage are discussed. Quantitative elemental analysis is obtained for thin film specimens using corrections for spectrometer response, absorption and background. Peak spectra are sorted using a method of profile fitting based on nonlinear simplex minimization. Using a simple analysis scheme, the peak data is reduced to elemental composition with an accuracy and precision on the order of 1%. Examples from Fe–Ni and Ho–Co alloys are given.
Über die Röntgenfluoreszenzanalyse von Aerosol‐Präparaten
Authors: Eberspächer H. , Schreiber H.
Published: May 2005

Zwei bei der Röntgenfluoreszenzanalyse von Aerosol‐präparaten auftretende Probleme werden behandelt: (1) eine einfache und genaue Methode zur Herstellung von Eichpräparaten. Es wird vorgeschlagen, definierte Lösungstropfen in einem exakten Punktmuster auf Filterpapier aufzubringen. (2) Die Korrektur der Streu‐ und Absorptionseffekte des Filters und der abgeschiedenen Schwebstoffe. Die aus Messungen in Einfach‐ und Dreifach‐Filterpaketen gewinnbaren Korrekturterme werden am Beispiel des erfahrungsgemäß kritischen Elements Calzium dargestellt.
Surface deterioration of ammonium acid phthalate crystals
Authors: Barrus D. M. , Blake R. L. , Burek A. J.
Published: May 2005

Ammonium acid phthalate crystals are observed to deteriorate in a high vacuum environment and to decrease in reflectivity.
Calibration and use of a lithium‐drifted silicon detector for accurate analysis of X‐ray spectra
Authors: Keith H. D. , Loomis T. C.
Published: May 2005

A detailed study of the performance of a silicon detector system is reported, with emphasis on the feasibility of using such a system for accurate quantitative analysis of X‐ray spectra covering a wide range of photon energies (2.5‐50 ke V). Calibration of efficiency, with an accuracy of ± 0.1% over most of this range, is described. Second order effects in the detection system have been characterized quantitatively, including escape peaks, pulses due to Compton recoil electrons, pulses whose energies are reduced because of incomplete charge collection and sum pulses. This information has been used to devise programs that permit accurate correction of spectra as recorded in a multi‐channel analyzer. Corrections are made for the following factors in turn; sum pulses, the second order effects enumerated above and detector efficiency. An analysis of the formation and distribution of sum pulses that represent close coincidences not resolved and eliminated by the pulse pile‐up rejector is given in an Appendix. Methods are described for removing sum counts, including ‘mixed’ sum counts, from spectra. The removal of these counts reduces the overall count but results in essentially undistorted representations of spectra as they would be recorded in a system having infinitesimal dead‐time. Some recommendations are made for improving the design of silicon detectors for quantitative spectral analysis.
Optimum ‘windows’ in quantitative energy dispersive analysis
Authors: Short M. A.
Published: May 2005

Optimum energy window widths are derived using random counting statistics for use in quantitative energy dispersive analysis over a wide range of peak‐to‐background ratios. It is shown that a peak energy window width equal to the full width as half maximum gives good results for most practical cases.
A simple dead‐time correction for X‐ray counting systems
Authors: Hutchison Charles S.
Published: May 2005

The dead time (t) of an X‐ray counting system may be readily determined to the nearest 0.4 μs by accurately measuring the counting rate per second (R) for any selected wavelength on two specimens, whose R values differ by a factor of approximately 10, at several tube or specimen currents. The R of the most intense specimen should cover the range up to 6 × 104 counts per second.

where a and b are the R values of the two specimens at one current, and a1 and b1 the R values of the same specimens at another. The average t is determined from as many current pairs as possible. All counting rates (R) are thereafter corrected by the equation

where R0 is the true and R the measured rates per second. R should not exceed about 6 × 104.

For energy‐dispersive detectors, the R values of Kα and Kβ peaks may be used from a single specimen and substituted for a and b in the above equation to obtain t.
Plant analyses by X‐ray spectrometry I—Low atomic number elements, sodium to calcium
Authors: Norrish K. , Hutton J. T.
Published: May 2005

Plants can be analysed for the elements sodium, magnesium, aluminium, silicon, phosphorus, sulphur, chlorine, potassium and calcium by X‐ray fluorescent spectrometry using discs pressed directly from dried and ground plant material. Fine grinding is essential to avoid particle size effects and the finely ground samples are self supporting when pressed.

Tables are given to correct for variations in absorption by the samples due to compositional changes, and also to correct for crystal fluorescence or scatter so that background measurements are not necessary on each sample.

Calibration has been made using chemicals added to cellulose and the results obtained on a series of samples agree (essentially within one standard deviation) with the mean values obtained by other methods. Results are also given for the standard kale sample.
The application of a ‘curve‐fitting computer program’ to compensate for inter‐element effects in X‐ray fluorescence analysis of rock samples. The determination of vanadium in geological standards
Authors: Riddle Chris , Smith T. E.
Published: May 2005

A computer program, used to ‘curve‐fit’ complex spectra of overlapping peaks in other spectral applications, has been used with X‐ray fluorescence data. Compensation is made for analytical error introduced through peak overlap. A typical case of this ‘inter‐element interference’, that of titanium upon vanadium, is taken to demonstrate the method. A comparison between the computer‐generated results and those determined by the conventional inter‐element correction method favours the curve‐fitting procedure.
Mise au Point du Dosage du Brome dans le Plasma et la Sueur à l'aide d'un Spectromètre à Fluorescence X à Source Isotopique Annulaire de Cadmium‐109
Authors: Barbier Y. , Pehlivanian E. , Girard C.
Published: May 2005

Il peut être intkréssant de doser le brome dans certains liquides biologiques. La présence d'autres éléments limite le choix des méthodes. L'analyse par spectrométric de fluorescence X paraít adaptée sous certaines conditions. Les auteurs décrivent une technique utilisant un spectromètre de fluorescence X non dispersif, dont la source d'excitation est constituée par un isotope radioactif: le Cadmium 109. Les facteurs de géométrie, le volume des échantillons, Ie choix des cellules, la reproductibilité des mesures sont étudiés, compte tenu des conditions imposées par le recueil des échantillons biologiques.
Accuracy of X‐ray fluorescence spectrometric determination of Rb and Sr concentrations in rock samples
Authors: Th. Verdurmen E. A.
Published: May 2005

It is shown that application of the Compton scattering method for matrix correction in the X‐ray fluorescence spectrometric determination of the trace elements Rb and Sr in rock samples can provide concentrations at a relative accuracy level of 1%. The empirical method applies to rock samples showing differences in mass absorption up to a factor of two. The accuracy of the method has been tested by analysis of 57 samples analysed for Rb and Sr by mass spectrometric isotope dilution. In addition a few of the U.S. Geological Survey (U.S.G.S.) reference rock powders, showing significantly different mass absorption, were analysed for Rb and Sr. It is demonstrated that the mica effect, if significant, is smaller than 1% relative. There is no advantage in the use of the LiF(220) analysing crystal as a substitute for the LiF(200). The method appears to be insensitive to the pellet thickness.
Crossed influence coefficients for accurate X‐ray fluorescence analysis of multicomponent systems
Authors: Tertian R. , Vié Le Sage R.
Published: May 2005

A thorough theoretical study of the typical iron–nickel–chromium ternary system confirms the essential variability of influence coefficients with composition, thus accounting for the limited validity of empirical coefficient procedures. The origin and mechanisms of coefficient variation are accurately described, namely by distinguishing between binary or ‘longitudinal’ variation, it being related to either an enhancement effect or the use of polychromatic excitation or possibly both, and ‘transverse’ variations resulting from fluorescence crossed effects as well as tertiary fluorescence if represented. As a consequence a general mathematical expression, including all these effects and exactly matching the theoretical intensity equations, is assigned to the coefficients for the entire range of compositions. On a practical basis, precision considerations allow to simplify these relationships considerably and reduce them to a fairly simple, flexible system of ‘crossed’ influence coefficients. Since it closely conforms to the fundamental principles of fluorescent emission, this new scheme should prove effective for determining multicomponent systems, namely by allowing accurate analysis to be performed over a wide range of compositions ‘without standards’.
X‐ray fluorescence analysis of catalytic converters using single‐element standards and theoretical corrections for interelement effects
Authors: Artz Bruce E.
Published: May 2005

An X‐ray fluorescence technique for the quantitative analysis of phosphorus, sulfur, chromium, iron, nickel, copper, zinc, zirconium, ruthenium, rhodium, palladium, barium, lanthanum, cerium, iridium, platinum and lead on fresh and used catalytic converters is described. The method used is to correct the measured X‐ray intensities of each element using theoretically calculated interelement absorption and enhancement effects so that they may be compared to X‐ray intensities measured on single element standards. The elemental concentrations are obtained from intensity calibration curves derived from the known compositions of the standards.
A procedure to increase signal in X‐ray spectrometry
Authors: Mathieson A. McL.
Published: May 2005

Use of an asymmetrically‐cut single crystal whose surface is polished optically flat can yield a considerable gain in signal over that available in the conventional symmetrical disposition in cases where high resolving power is not critical. Adjustment of the level of asymmetry is achieved simply by rotation of the wedgeshaped crystal about the perpendicular to the Bragg plane used.
Experimental spectral distribution versus Kramers' law for quantitative X‐ray fluorescence by the fundamental parameters method
Authors: Laguitton Daniel , Parrish William
Published: May 2005

Quantitative X‐ray fluorescence analysis by the fundamental parameters method and the LAMA Program shows that the experimentally determined spectral distribution leads to accurate results whereas the continuous spectrum calculated from Kramers' Law often leads to relatively large errors. The primary characteristic line spectrum of a W tube at 45 kV may cause most of the fluorescent intensity, e.g. nearly all the Ni K and about 60% of Cr K.
Total X‐ray fluorescence analysis of geological samples using a low‐dilution lithium metaborate fusion method. Matrix corrections for major elements
Authors: Haukka M. T. , Thomas I. L.
Published: May 2005

A low‐dilution fusion method (1:2, sample to lithium metaborate) has been investigated for the determination of ten major elements in geological samples and the results are shown to have an accuracy comparable to those obtained using the well‐known heavy‐absorber method. Experimental determination of matrix coefficients employed natural rock standards (alone, mixed or spiked with synthetic oxides), and synthetic oxide mixtures covering a broad range of compositions of the ten most naturally‐abundant oxides. The method of determining the correction coefficients is described. Flexibility of sample preparation is a feature. Experiments with varying dilution ratio (from 1:1 to 1:15, granodiorite to flux) show that the same set of correction parameters can be used throughout the range. This is practically important for samples with large ignition losses or gains and in certain other applications. Systematic differences between calculated mass absorption coefficients and the experimentally‐derived correction parameters are documented and can be used in predicting parameters for additional elements. The greatest potential benefit of the low‐dilution method is in automated analysis of geological and industrial samples (rocks and soils, ores and bauxites, slags, glasses, cements, refractories) for major and trace elements using only one glass disc.
X‐ray K emission spectra of vanadium in various oxidation states
Authors: Yasuda S. , Kakiyama H.
Published: May 2005

The Kα1,2, Kβ1,3, Kβ5, and Kβ″ emission spectra of vanadium in the element and several V (III), V(IV), and V(V) compounds have been measured with a two‐crystal X‐ray spectrometer. The Kα1 and Kβ1,3 peaks shift slightly to lower energies with increasing lthe oxidation state of vanadium atom and the Kβ5 peak shifts to higher with it. An approximately linear relationship between Kα1 width and Kα1/Kα2 intensity ratio can be used for lindentification of vanadium oxidation state.
A critical investigation of energy‐dispersive microprobe analysis of steel using the Reed/Fiori method of background calculation
Authors: Comins N. R. , Thirlwall J. T.
Published: May 2005

Published investigations of the energy‐dispersive microprobe analysis of stainless steel repeated using the Reed/Fiori method of calculating the background intensity distribution. It is shown that the ‘interference effect’ in Kβ/Kα intensity ratios for elements in steels, which arose from studies using the Fourier transformation and frequency filtered background subtraction method, is due to deficiencies in this method. The systematically negative errors in analyses of Ni in steel are studied and can be corrected by using the Reed/Fiori method.
Electron probe microanalysis applied to very thin layers of aluminium‐nickel alloys
Authors: Dužević D. , Bonefačić A.
Published: May 2005

In order to determine the composition of very thin homogeneous layers of multi‐component systems, a reinterpretation of G. A. Hutchins' Method for elemental metal films was worked out. This made it theoritically possible to calibrate for the composition of complex n‐component fims by using massive standards of pure constituents as is done in the case of bulk samples. The method was supplied to very thin layers of AlNi alloys and the results are compared with those obtained by means of emission X‐ray spectrometry.
A comparison of the transmission properties of 1 μm and 6 μm polypropylene flow counter windows
Authors: Seaman A.
Published: May 2005

Over recent years, some confusion has arisen regarding the transmission properties of commercially available frame‐mounted polypropylen flow counter windows compared to those of the loose sheet polyethylene teraphthalate (Mylar) material previously available. Experimental results obtained for Ca to F Kα characteristic radiations inclusive enable the transmissions of 6 μm Mylar 1 μm polypropylene to be calculated which in turn are compared to earlier published data.
Determination without standards of small amounts of metal compounds on microfilters by X‐ray fluorescence spectrometry
Authors: Ohno Katsumi , Fujiwara Jun , Morimoto Ichiro
Published: May 2005

The extracted minor phases in superalloys are analyzed by X‐ray fluorescence spectrometry without the use of standards. The calculation in the analysis is simplified by using a monochromatic X‐ray source and the fundamental parameter method. The extracts on the microfilter are approximated by thin film on the filter substrate, though the extracts were not homogeneous. This source permits a simple calculation using the thin film model to transform the measured X‐ray intensity to mass thickness and mass fraction, since the mass absorption coefficient for the primary beam is easily found in a commercially available table. A great advantage of this method is that the calculations are possible by using a small programmable calculator.
A technique for the analysis of odd‐shaped samples by means of X‐ray fluorescence spectrometry
Authors: Wybenga F. T.
Published: May 2005

Odd‐shaped pieces of material were analysed by first setting them in a thermoplastic resin containing copper or iron powder. In subsequent measurements the copper or iron was used as monitor to correct the measurements on the sample. Corrections for coincidence losses of counts were found to be very important when applying this method.
X‐Ray secondary fluorescence in matrix correction
Authors: Plesch R.
Published: May 2005

Rasberry and Heinrich1 have proposed a mathematical statement for the correction of secondary excitation based on experimental observation. It will be shown that the mathematical form of this statement can also be confirmed physically. With regard to the coefficients, suggestions will be made which should provide a greater, general validity of the statement. Finally, the statement will also be extended to analytical problems in which the intensity of the matrix elements will be used for matrix correction, instead of their concentrations.
The application of a 100 kV X‐ray tube to topographic research
Authors: Ivanov S. A. , Shchukin J. A.
Published: May 2005

The design and characteristics of a 100 kV X‐ray tube for diffraction topography of single crystals are described.
Element mapping by a scanning X‐ray system
Authors: Gurker N.
Published: May 2005

Physical surface analysis methods using charged particles on the excitation side can easily be applied to elemental distribution mapping. One common feature of all known methods is that they work on a micron scale, with respect to spatial resolution and investigated sample area. This paper deals with a new approach to the problem of element mapping using X‐ray fluorescence radiation. In contrast to the well‐known scanning procedures, this method allows the investigation of larger areas (several square centimetres) at lower spatial resolutions (≳ 100 μ). The method applies a mechanical scanning device, a modern energy‐dispersive detector and a computer. The scanning unit allows translation and rotation movements of the sample. By generating a line‐shaped X‐ray beam and translating the sample across the fixed X‐ray strip while measuring the intensity of the fluorescence radiation in a specified energy window, one obtains a strip resolution of the species investigated. If many translation measurements are made under different angular orientations of the sample, a computer converts the strip resolutions of the scanning profiles into a point resolution of the specified element. The mathematical background is known in the literature as ‘representation of a function by its line integrals’ or ‘image reconstruction from projections’. Computer simulation studies and experimental results will be discussed.
Prediction of mass absorption coefficients from inelastically scattered X‐radiation for specimens of less than ‘infinite thickness’
Authors: Kieser R. , Mulligan T. J.
Published: May 2005

An equation is developed which describes the X‐ray scatter radiation from specimens of any thickness. This equation suggests that a specimen's mass absorption coefficient can be determined from its inelastically scattered X‐radiation not only when the specimen is ‘infinitely thick’ but also when it is of ‘intermediate thickness’. Measurements have been carried out with a standard energy‐dispersive X‐ray spectrometer on specimens of ‘intermediate thickness’. Good agreement is obtained between the mass absorption coefficients that are calculated from the scattered radiation and those obtained on the basis of tabulated mass absorption coefficients for the elements.
Ion‐implaned reference standards for the analysis of surface impurities by X‐ray fluorescence spectrometry
Authors: Gries W. H. , Wybenga F. T.
Published: May 2005

X‐ray fluorescence spectrometry is capable of the quantitative determination of impurities in and on solid surfaces in concentrations of fractional atomic monolayers. This capability could not be exploited to any large extent in the past due to the lack of suitable standard reference materials. By means of quantitative ion implantation, however, such standards can now be manufactured. They are described and formulae are derived for correcting the fluorescent signal for attenuation due to depth distribution of the impurities as well as for interelement excitation in matrices of higher atomic number than the impurity.
Estimation of the chemical composition of precipitated phase by the electron beam microanalytical technique
Authors: Chatterji S. , Thaulow N.
Published: May 2005

The problem of estimating the chemical composition of small particles of a phase in a matrix of another occurs in a number of fields. The introduction of electron beam microanalytical techniques has made it possible to analyse a volume of 10μm3. In spite of this advancement the chemical composition of the particles themselves is difficult to determine. This difficulty arises from uncertainty as to the full containment of the analysed volume by the particle being analysed. In this paper a statistical approach to establish the chemical composition of the particles themselves has been proposed. This approach is particularly useful when the particles and the matrix have a common element. Two examples are given, one with components of known compositions and another with a component of an unknown composition.
Radiometric diameter concept and exact intensities for spherical particles in x‐ray fluorescence analysis
Authors: Markowicz A. , Van Dyck P. , Van Grieken R.
Published: May 2005

In X‐ray fluorescence analysis the concept of radiometric diameter, d, is often introduced in considerations of the fluorescent intensity from a particulate sample. It represents the mean geometric path of the X‐rays through one particle and is usually simply taken to be equal to the volume‐to‐area ratio of the particle. The effective radiometric path is, however, itself dependent on geometry and absorption effects. Rigorous calculations of the fluorescent intensity from a particle in the π and π/2 geometries were carried out to evaluate the errors involved. It appears that, for π geometry, the discrepancy between these exact results and the intensity calculated via the use of d does not exceed 5.2%. For the π/2 geometry, the errors are much larger and can amount to 50% in realistic cases of X‐ray fluorescence analysis. These conclusions are also applicable to monolayers. The effective radiometric diameter approaches d only when absorption effects become negligible, but is smaller in other cases.
X‐ray K absorption studies on some 1,10 phenanthroline‐based cobalt complexes
Authors: Kumar A. , Nigam A. N. , Shrivastava B. D.
Published: May 2005

The X‐ray K absorption edges of Co in some 1,10 phenanthroline‐based complexes of cobalt have been recorded. The results have been discussed qualitatively in terms of the effective nuclear charge on the central metal atom and the nature of the ligand.
Multilayer X‐ray spectrometry in the 20–80 Å region: A molecular orbital analysis of CO and CO2 in the gas and solid states
Authors: Perera R. C. C. , Henke B. L.
Published: May 2005

Optimized multilayer X‐ray spectrometry, using lead myristate and lead stearate analyzers (2d values of 80 and 100 Å) has been applied to the measurement of the O‐‐Kα and the C‐‐Kα spectral bands from CO and CO2 in the gas and solid phases. The LII, III spectra were also measured for argon in the gas and solid states under similar conditions in order to identify and to minimize any non‐molecular components in the CO and CO2 spectra. These molecular orbital data have been related to those obtained with X‐ray and ultraviolet photoelectron spectroscopy and grating X‐ray spectroscopy. The consistency of the results of these complementary measurements is excellent. The ionization energies for the C and O 1s levels have been determined to be 295.4 and 542.0 eV for CO and 296.8 and 540.3 eV for CO2. The MO data have also been compared with that predicted from the symmetry, strength and binding energy of the molecular orbital spectral components as calculated using the currently available computational models, CNDO/2, MINDO/3, MNDO, extended Hückel and ab initio. The molecular orbital calculated results for these organic compounds, CO and CO2, are not in as good agreement with the experimental data as previously demonstrated for molecular orbital spectra measured for C‐‐Kα and the LII, III bands of Cl, S and P for both organic and inorganic compounds.
The influence of tube voltage rectification in X‐ray fluorescence analysis without standards
Authors: Mantler M.
Published: May 2005

The spectral photon distribution from X‐ray tubes operated at constant potential is compared to the distribution resulting from self rectification circuits. Kramers' equation is modified by calculating the average values of the photon flux during one period of voltage fluctuation and the results are used to transform Gilfrich and Birks' experimental tube spectra to those expected from a half‐wave rectification circuit. The effect of using both constant potential and sine wave potential, as well as constant potential with overlaid sine wave ripple, is discussed. Results are shown by using experimental data from Ag‐Au‐Cu alloys and ‘no standard’ methods (data evaluation without reference specimens).
Quantitative X‐ray fluorescence analysis of thin films using LAMA‐2
Authors: Huang T. C.
Published: May 2005

An improved version of the LAMA program for the quantitative analysis of composition and mass thickness of thin film materials by X‐ray fluorescence (XRF) has been developed. The divergence and slow convergence problems occasionally experienced with the LAMA‐1 program have been eliminated by using the linear approximation method and the algorithm of simultaneous refinement of composition and thickness to greatly increase its capability and performance. A study of over a hundred simulated thin films showed that the LAMA‐2 program converged much faster than LAMA‐1 and gave better accuracy. The efficiency of the program has been improved to the point where it is feasible to operate on a minicomputer.
Measurement of K X‐ray fluorescence cross‐sections
Authors: Bhan Chander , Chaturvedi S. N. , Nath N.
Published: May 2005

Absolute values of K X‐ray fluorescence (XRF) cross‐sections have been calculated for elements 11 ⩽ Z ⩽ 69 at three excitation energies corresponding to Mn, Ag and Te K X‐rays from 55Fe, 109Cd and 125I radioisotopes respectively and the fourth energy corresponding to the 59.60 keV γ‐ray from 241Am. Measurements were also made for these cross‐sections for ten elements with 18 ⩽ Z ⩽ 48 at two excitation energies from 109Cd and 125I radioisotopes. The measured values are compared with those obtained from theoretical considerations and a good agreement is found.
Quantitative determination of the various forms of aluminium in steels by X‐ray fluorescence spectrometry
Authors: Grimaldi R. , Paris V. , Mariani E.
Published: May 2005

The aluminium content in steels is particularly important in the improvement of the yield ratio, ageing and magnetic properties, ductility (for marking sheets) and also in the primary metallurgy (continuous casting). From the metallurgist's viewpoint it is important to determine the soluble aluminium content only (i.e. AIN and Al solid solution) and the way this affects some of the mechanical properties. Conventional analysis is time consuming and cannot be employed on‐line therefore it would be useful to employ instrumental analysis. Several approaches have been investigated in the past using emission spectroscopy but this was found to be too complicated and expensive. A new method, described here, uses an X‐ray emission technique which yields good results and can be carried out on a commercially available X‐ray spectrometer without other facilities.
An improved method of x‐ray fluorescence analysis of chrome containing refractories
Authors: Banerjee Subrata , Olsen Ben G. , Hess Melvin K.
Published: May 2005

An improved x‐ray fluorescence method has been developed for the analysis of chrome containing refractory materials (raw materials, in process and final products). It involves the fusion of the powdered samples with a mixture of sodium hexametaphosphate and lithium metaborate in the presence of lanthanum oxide into a glass disc followed by polishing of the disc before exposure to the x‐rays. Three British standards, two South African Standards and one NBS Standard were used for standardizing the method. SiO2, Fe2O3, Al2O3, CaO MgO and Cr2O3 were used in the standardization because these compounds constitute the majority of the materials under analysis. Linear regression analysis of the data showed that all the lines were linear, the coefficient of determination being equal or close to 1.00 with a mean error of less than ±3.5%, excepting CaO which had a mean error of ±8.6% because of its low concentration and the larger variance in its standard value.
Quantitative determination of argon in sputtered films by wavelength‐dispersive electron probe microanalysis
Authors: Willich P. , Obertop D.
Published: May 2005

A method is described for the calibration of Ar Kα counting rates, measured using crystal spectrometers equipped with Ar‐flow proportional counters. Linear extrapolation from overvoltage corrected x‐ray yields of the elements with Kα x‐ray energies lower than those of the ArK absorption edge gives an accurate description of the experimental Ar Kα intensity ratios from counters operated at different values of gas pressure. Results of all‐element film analyses provided by a matrix correction procedure, ZAF, indicate an accuracy better than 5% relative for the determination of Ar concentrations ranging from 0.1 to 10 wt%.
Analysis of finely divided metal particles formed in montmorillonite by scanning electron microscopy
Authors: Patel M.
Published: May 2005

Finely divided metal particles, formed in the interlayer space of montmorillonite, have been identified by a x‐ray microprobe technique and their dimensions measured by scanning electron microscopy. The dimensions of Ni0 and Cu0 obtained on reduction of the respective metal ions by H2 have been shown to be ∼ 100 Å.
A modified background‐ratio method for x‐ray fluorescence analysis of soil and plant materials
Authors: Livingstone L. G.
Published: May 2005

The isolated atom model of x‐ray scatter has been used to develop a new analytical strategy for internal standardization in x‐ray fluorescence spectrometry. The method defines quantitatively by how much and within what limitations various background‐ratio calibration techniques can improve results for particular elements in specific materials. The analytical strategy is based on a modified peak to background ratio equation, where the background intensity is raised by an exponent T. The variable T combines as special cases all existing analytical strategies which use scattered x‐rays, together with the basic linear calibration where T=0. Variation in T was evaluated using extensive computer processing of matrix data for typical soil and plant materials. It was found that T varied with analyte, scatter wavelength and the matrix component contributing to the mass absorption error. Most existing methods using a background‐ratio technique are shown to be improved by using a value of T other than the previously assumed unity or zero.
The complete spectral response for EDXRF systems—calculation by Monte Carlo and analysis applications. 2—heterogeneous samples
Authors: Doster Joseph M. , Gardner Robin P.
Published: May 2005

The Monte Carlo model for predicting the complete spectral response from homogeneous samples has been extended to heterogeneous samples which may be considered to be spherical particles suspended in a homogeneous matrix. The spherical particles may have any distribution of size and spatial position as specified input. The particle compositions are either: Model 1‐a homogeneous mixture of all the sample elements present or Model 2‐a single pure element appropriately chosen at random from those present. These two sample compositions should represent extremes of the matrix interferences encountered in practice and should, therefore, bound the x‐ray and source scattering spectral responses observed. The sample Monte Carlo results reported here for both heterogeneous models approach the limiting values predicted by the homogeneous model when used for decreasingly small particle sizes and generally exhibit a smooth relationship with particle size. Although comparisons with two sets of experimental results are not entirely satisfactory, the general trends are properly predicted. It is concluded that the models are accurate within our present capability of testing them (at present we only have available two particle spatial distributions for packing fractions of 0.4 and 0.6, both for particles of uniform size).
Modifications of the HEX program for fast automatic resolution of PIXE‐spectra
Authors: Johansson Gerd I.
Published: May 2005

The computer program ‘HEX’ for resolving PIXE‐spectra has been modified. By irradiating standard foils, the escape peak ratios for x‐ray peaks in the energy interval 3.3‐10.6 keV have been measured. The results have been compared with theoretical calculations and experimental results of other research groups. The escape peaks have been included in the computer code. Pile‐up peaks in the x‐ray spectrum are also fitted by the modified computer program. This procedure is independent of the count rate and the pile‐up interval. In addition, an effective routine for rejecting small x‐ray peaks has been developed.
The influence of the fluorescence volume on the observed yield in energy dispersive XRF analysis
Authors: Weber Anders
Published: May 2005

It is shown that when a narrow x‐ray beam is used in energy dispersive fluorescence analysis of thick, low‐Z samples large deviations from the predictions of the commonly used fundamental parameter model occur. A simple method by which the effects can be studied empirically is described. An approximate model allowing a direct calculation of the effécts is introduced. The validity of the model has been confirmed experimentally.
An x‐ray spectrometer with a position‐sensitive wire detector (PSD)
Authors: Ebel H. , Mantler M. , Gurker N. , Wernisch J.
Published: May 2005

A new crystal‐type x‐ray spectrometer is described, which employs a position‐sensitive detector for simultaneous radiation detection in a certain energy range given by the spectrometer design. The main specifications are (a) better energy resolution and (b) longer data collection times compared with an energy‐dispersive spectrometer.
The effect of elastically scattered protons on the energy resolution of x‐ray detectors in PIXE measurements
Authors: Mingay D. W.
Published: May 2005

Extensive use has been made of particle‐induced x‐ray emission (PIXE) analysis over the past several years. The optimization of its detection sensitivity calls for the judicious selection of several parameters including, inter alia, the beam energy used and the x‐ray window thickness. Thin windows are required in order to detect the light elements whose x‐ray energies are so low that they are heavily attenuated by any absorber material between the target and the detector. The choice of beam energy is dependant on the respective x‐ray production cross‐sections for elements of interest, the related background generated, as well as the associated beam energy degradation in the targets. These considerations often lead to a state where protons, elastically scattered from the target, have sufficient energy to penetrate the window and enter the x‐ray detector. The extent to which such protons and their related secondary electron production affect the energy spectrum resolution of intrinsic germanium and Si(Li) x‐ray detectors is demonstrated for a proton beam energy range from 2.1 to 3.5 MeV with a window thickness equivalent to the range of a 2.5 MeV proton.