bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fundamental coefficient method applied to a quasi‐monochromatic excitation
Authors: Broll N. 
Published: May 2005

AbstractThe fundamental or effective influence coefficients are derived from the theoretical fluorescence intensities. For a monochromatic excitation, the calculations are simplified and do not require the spectral intensity distribution of the x‐ray tube. The use of the fundamental coefficient method applied to a quasi‐monochromatic excitation is illustrated by a practical application of the analysis of stainless steel and a high‐temperature alloy. The measurements were made with an energy‐dispersive spectrometer.
Glass disk fusion method for the X‐ray fluorescence analysis of rocks and silicates
Authors: Alvarez Moisés 
Published: May 2005

AbstractA study of the physical and practical aspects needed for a successful solid solution method for XRF analysis is presented in the light of the theory and practice of the glass‐making industry. An inexpensive manual glass disk sample preparation method is proposed that gives a well annealed disk that can be ground and polished without any losses due to breakage.
Novel method for estimation of the effective nuclear charge (Zeff) on the metal atom on cobalt complexes from the x‐ray absorption discontinuity
Authors: Khadikar Padmakar V. 
Published: May 2005

AbstractA novel method for estimation of the effective nuclear charge (Zeff) on the central metal atom in cobalt complexes from the x‐ray K‐absorption discontinuity is proposed. Its potential is discussed on the basis of statistical analysis of the data obtained from the results for 25 cobalt complexes which indicated fairly good agreement between the observed and the estimated values of Zeff for the cobalt atom.
Semiempirical model for correction of matrix effects in on‐stream x‐ray fluorescence analysis
Authors: Stoev Krassimir Nedialkov 
Published: May 2005

AbstractA semiempirical non‐linear model for the on‐stream x‐ray fluorescence analysis of slurries was developed, utilizing the intensities of fluorescent and scattered radiation. It is assumed that the slurry consists of liquid and solid parts. All components of the solids except the elements to be measured are considered to be a filling substance with an approximately constant absorption coefficient. The model permits the calculation of the elemental weight fractions in the solids without the need for the determination of the solid content in the slurry. The accuracy and reproducibility of the method are compared with those of existing multiple regression models. A non‐linear expression for the determination of the solid content in the slurry using the intensity of scattered x‐radiation is proposed and compared with some polynomial regression models.
Evaluation of spectrum overlap correction in energy‐dispersive x‐ray spectrometry using the digital filter deconvolution procedure: Application to selected interferences encountered in the microprobe analysis of minerals
Authors: Potts Philip J. , Tindle Andrew G. 
Published: May 2005

AbstractAn evaluation was undertaken to characterize the accuracy and effectiveness in the deconvolution of energydispersive x‐ray spectra of the overlap correction procedure based on a digital ‘top hat’ filter and least‐squares fitting of library spectra using an algorithm developed by Statham. This deconvolution procedure was applied to x‐ray spectra recorded by electron microprobe to represent interferences that range in severity from minor to severe, specifically overlap between (i) Cr/Mn K lines, (ii) Ba L and Ti K lines, (iii) Au/Pt L and M lines and (iv) Bi/Pb L and M together with S K lines. A novel calibration procedure was used to simulate spectra and so avoid the requirement to obtain and analyse a large number of mineral standards. This procedure involved superimposing x‐ray spectra from individual elemental standards counted for a range of count times suitable for testing the deconvolution program. The results demonstrated that reliable deconvolution could be achieved down to <1% Cr in a manganese matrix, 2.5% Ba in a titanium matrix, <2.5% Au in a platinum matrix (based on either L or M lines) and about 2.5% Bi in a Bi–Pb–S matrix using the M lines of Bi and Pb. Within the fitting error calculated by the deconvolution program, bias from expected values was not detected excepted when Bi, Pb and S were fitted to the simulated spectrum of bismuthite (Bi2S3). Small discrepancies in the Bi and S values were then observed. Overall, it was concluded that in cases of severe overlap, numeric data from the spectrum deconvolution program were a more reliable indicator of the presence of an element than visual examination of the original spectrum.
Energy‐dispersive x‐ray fluorescence analysis of borax beads using double dilution without comparison standards
Authors: Muia L. M. , Van Grieken R. 
Published: May 2005

AbstractA method for the energy‐dispersive x‐ray fluorescence analysis of geological materials in borax glasses without standards is described. The usefulness of the procedure was demonstrated by analysing five certified sedimentary rock reference materials for Al2O3, SiO2, CaO, TiO2, MnO and Fe2O3. The experimental results show reasonable agreement with the certified values. The method has a theoretical precision of 2% when dilution ratios of 6 and 12 are used. The actual precision of the method ranges from 4 to 15% for these element oxides. For the major oxides considered, the procedure can be useful when certified or well characterized geological standards are not available.
Application of delayed x‐ray spectrometry to the analysis of some rare earth elements
Authors: Pillay A. E. , Mboweni R. C. M. 
Published: May 2005

AbstractThe capabilities of delayed x‐ray spectrometry preceded by isotope‐source thermal neutron activation for the specific determination of some rare earth elements (Sm, Eu, Dy, Ho) in small powdered samples was evaluated. The feasibility study relied heavily on the low‐energy sensitivity of the detector used. Detection of the delayed x‐rays was achieved with a 100‐mm2 Ge detector with the ability to produce optimum photopeak‐to‐noise ratios. The rare earth elements were chosen on the basis of their inherent favourable nuclear properties for producing a practicable x‐ray yield and on the demand for their analysis. Analytical results are presented over a range of concentrations for the elements of interest and the potential of the technique for application to their general routine analysis is discussed. Interferences from the sample matrix can be suppressed to an extent that makes the method almost independent of the matrix. This and other features make the technique a strong rival to conventional activation analysis.
Determination of phosphorus in borophosphosilicate or phosphosilicate glass films on a silicon wafer by wavelength‐dispersive x‐ray spectrometry
Authors: Levine Herman S. , Higgins Karen L. 
Published: May 2005

AbstractA wavelength‐dispersive x‐ray fluorescence method was developed for the determination of phosphorus in borophosphosilicate glass (BPSG) or phosphosilicate glass (PSG) films on a silicon wafer. Secondary spectral line intensities from the coated wafer are compared with those of an uncoated Si wafer and a fused P standard. The results are then converted to phosphorus content and surface density of the film by equations for the relative spectral line intensities of P and Si with corrections for the shift in the Si peak due to chemical bonding. Results obtained on an annealed set of PSG samples using four different incident spectra were self‐consistent and correlated well with independent inductively coupled plasma atomic emission spectrometric analyses for phosphorus and ellipsometric measurements of thickness. Preliminary results with BPSG samples were promising and showed that results for phosphorus were not sensitive to boron concentrations in the films.
Sample area dependence in quantitative EDXRF analysis
Authors: Boman J. 
Published: May 2005

AbstractThe measurement of small, thin samples with an area of the order of mm2 with the ordinary EDXRF technique requires that special care be taken to include the sample size in the evaluation of element concentrations. Results are reported obtained using a standard procedure for the evalution of small samples used in the author's laboratory. This procedure makes use of an input parameter, viz. a ‘geometrical factor’ corresponding to the sample area which is used in the evaluation software. The results show that an almost straight line can be fitted to describe the parameter as a function of sample area for small samples (with an area of the order of mm2), but that the corrections for inhomogeneity of the beam intensity are needed in many cases. For large samples (with an area of the order of cm2) the parameter is equal to unity.
Comprehensive major, minor and trace element analysis of a submarine polymetallic nodule by wavelength‐dispersive x‐ray fluorescence spectrometry
Authors: Cai Shulin , Guo Yulin , Li Jie 
Published: May 2005

AbstractA method was developed for the determination of major, minor and trace elements in a submarine polymetallic nodule by x‐ray fluorescence spectrometry. Fusion of the sample was performed in gfraphite crucibles using a 1:3 dilution ratio with an Li2B4O7Li2CO3LiNO3 flux. Calibration was carried out with synthetic standards. The absorption‐enhancement effects for 28 analytes were each corrected using influence coefficients generated by the COLA equation. The results obtained were in relatively good agreement with the recommended values for the Chinese reference material GSPN‐1. The technique of sample preparation and the use of synthetic standards can also be extended to the analysis of other polymetallic ores.
Caveat emptor: Gross refraction effects pose problems in the use of multilayers for soft x‐ray spectroscopy
Authors: Luck Sara , Urch David S. , Zheng Dao Hong 
Published: May 2005

AbstractFirst‐ and higher order reflections from a molybdenum‐boron carbide multilayer (nominal 2d 200 Å) have been studied. In the first order the apparent 2d spacing was found to increase, and then to decrease, with increasing wavelength and angle of incidence, whereas for higher orders it increased with order, converging to a limit (2d∞) of about 210.5 Å. Strong refraction effects were invoked to rationalize this behaviour, and the refraction constant δλ was found to vary from 2 × 10−3 to 50 × 10−3 for the wavelength range 23.5−135 Å. Experimental procedures to calibrate multilayers for soft x‐ray spectroscopy, by first determining 2d∞ and then δλ values for various wavelengths, are described.
Trihydroxymethylaminomethane high‐efficiency x‐ray analyser crystal
Authors: Su Genbo , Li Zhengdong , Huang Gongfan , Pan Feng 
Published: May 2005

AbstractComparison of the x‐ray analyser properties of trihydroxymethylaminomethane (TAM) and pentaerythritol (PET) crystals showed that the TAM crystal has a higher efficiency.
Measurement of relative intensities of L‐shell x‐rays of some heavy elements using Cd‐109 radioisotope source
Authors: Darko J. B. , Tetteh G. K. 
Published: May 2005

AbstractThe relative L‐shell x‐ray intensities of Sm, W, Ir, Au, Hg, Pb and U were measured using a Cd‐109 radioisotope source and a Si(Li) detector. The measured relative intensities were compared with the theoretically calculated values due to Scofield, computed for the present excitation energy of 22.6 keV. The experimental results were found to agree with theory in most cases.
A compton peak method for incident angle determination in XRF with annular excitation
Authors: Greaves E. D. , Bohus L. Sajo , Marcó L. , Alvarez M. 
Published: May 2005

AbstractEstablished methods for measuring the incident angle related to XRF when radioisotope annular sources are involved are briefly discussed. As an alternative technique, a direct measurement of the incident angle from the measured spectrum of the Compton scattered energy was developed. Analysing published experimental data, the limit of validity of this new approach is defined and it is established that for the sensitivity determination only the spectral data are required.
Effect of the photon intensity selected at various positions under the photopeak on the mass attenuation coefficient of x‐rays
Authors: Kerur B. R. , Thontadarya S. R. , Hanumaiah B. 
Published: May 2005

AbstractThe variation in the value of the mass attenuation coefficient of x‐rays in aluminium was studied by counting photons under various positions in the photopeak employing a proportional counter spectrometer system with a good geometrical set‐up. The effect of (small angle) scattering was also examined using three different sets of collimators of diameter 9, 6 and 3 mm and employing both a pure x‐ray source (55Fe) and a mixed radiation source (57Co). The μm values obtained at the FWHM position for each set of collimators agree closely with the theoretical values.
Dependence of the accuracy of the results of steel x‐ray fluorescence analysis on the method of considering the variation of α coefficients with sample chemical composition
Authors: Molchanova E. I. , Smagunova A. N. , Gunicheva T. N. , Smagunov A. V. 
Published: May 2005

AbstractThe accuracy of the results of steel x‐ray fluorescence (XRF) analysis using certain computation algorithms, differing in the way in which they consider the dependence of α coefficients on sample composition, was compared by means of the determination of chromium in steel standard samples, the chemical compositions of which represent possible compositional variations of 456 different types of high‐speed, high‐, medium‐ and low‐alloy steels. It is shown that in the XRF analysis of steels, the best accuracy is provided by algorithms in which this dependence is based on real variations in the concentration of interfering elements. Algorithms using constant influence coefficients may also give acceptable accuracy of XRF results provided that more exact calculation of equation parameters, by which the values of reduced element concentrations are obtained, are found. Recommendations for increasing the accuracy of these parameter calculations are given.
Background determination in wavelength‐dispersive electron microprobe analysis: Some difficulties and presentation of a new analytical model
Authors: Fialin Michel 
Published: May 2005

AbstractA background (BG) model is proposed for the determination of minor and trace element compositions with an electron microprobe (wavelength‐dispersive spectrometry). This model is particularly useful when a major band partially overlaps the peak corresponding to the element of interest. Its relationship is derived from a second‐order polynomial and can be written as Bv = (B1 + B2)/2 + (1 + KBG)(B2 − B1)/4, where B1 and B2 represent BG measurements to be performed on two symmetrical positions with respect to the analysed peak and KBG is a coefficient to be determined on a standard (BG standard) free from the sought‐for element but containing the overlapping peak. No BG standard with an approaching unknown matrix composition is required. An important feature is the shape of the overlapping band, which should be identical in both standard and unknown (at least within the energy range where measurements are performed). This last point is discussed using the example of elements whose analysed peaks are situated close to the Kβ1, 3 bands of transition metals. The shape of such bands, which are related to valence states in the x‐ray emission processes, depends on the atomic chemical environment. Ti and Cr Kβ1, 3 profiles, emitted from pure metals and some oxides, are usefully compared in this respect. The capabilities of the model were tested on the determination of Mn in Cr‐rich compounds (Cr Kβ1,3 strongly overlaps Mn Kα).
X‐ray K‐absorption edge studies in a‐Ga30Se70 and a‐Ga30Se70 − xInx
Authors: Malik M. Manzar , Nigam A. N. , Husain M. 
Published: May 2005

AbstractThe shift of the K‐absorption edge (ΔEk) was measured in ternary alloys of Ga30Se70‐xInx (x = 0, 5, 10, 15, 20) with respect to the binary Ga30Se70 alloy. It was observed that the K‐edge of selenium shifted progressively towards the lower energy side as the indium concentration increased from 0 to 10 at.%. However, at higher concentrations, the relative shift started to decrease. These results are in accordance with Pauling's concept of electronegativity and indicate that the nature of the bond is iono‐covalent in these glasses, as found in many crystalline solids. The composition dependence of the edge shift is also discussed in terms of the structure of the SeGa system.
Background correction procedure for multi‐channel x‐ray fluorescence spectrometers
Authors: Gunicheva T. N. , Afonin V. P. , Finkelshtein A. L. 
Published: May 2005

AbstractA background correction procedure is described for multi‐channel x‐ray fluorescence spectrometers/quantometers with spectrometric channels of a fixed type. The background intensities are measured for a special background sample. Background intensities of the unknown sample are calculated from these measurements with the help of s and f corrections, taking account of qualitative and quantitative differences in the spectral composition of the background radiation for both an unknown specimen and the background sample. Determinations of the major elements in rocks on a multi‐channel x‐ray fluorescence quantometer demonstrated the capabilities of this procedure.
Figures‐of‐merit, their philosophy, design and use
Authors: Jenkins Ron , Gilfrich John V 
Published: May 2005

AbstractFigures‐of‐merit (FOMs) is a term which is used to define the quantitative measure of performance based on parameters which can be determined by the experimentalist. The FOM may be intuitive, based on previous experience of the analyst or his personal assessment of the importance of certain parameters, or derived, based on measurable parameters or on mathematically deduced data, mostly involving statistics. The FOM may also be a combination of intuitive and derived factors. In this review, a number of commonly used FOMs, due to several authors, are considered. They are categorized by their originators, their type (intuitive, derived or a combination therof), their primary application and the factors on which they are based. The applications discussed include both x‐ray spectrometry and x‐ray diffraction, but many of the principles apply equally to both.
Kα x‐ray emission induced by 1—100 MeV protons
Authors: Bassi Stefano , Gianforma Giuseppe , Silari Marco 
Published: May 2005

AbstractIn the course of a feasibility study of high‐intensity sources of monochromatic x‐rays to be used for XRF, extensive numerical calculations were conducted on the production of characteristic x‐rays by proton bombardment of pure element targets. This paper presents the analytical model used for the computer simulations and compares the x‐ray production by protons and alpha particles. The K x‐ray production cross‐section was calculated by the ECPSSR theoretical model and by Paul's analytical formula. The dependence of the x‐ray yield on projectile energy, target atomic number, target thickness and irradiation geometry is discussed. The thick target Kα x‐ray yields produced by 1—100 MeV proton bombardment were calculated for 66 elements from Na to Pb. From these results, a number of scaling laws and fitting procedures are given for proton‐induced Kα x‐rays.
Analysis of desert rose using PIXE and RBS techniques
Authors: Al‐Kofahi M. M. , Hallak A. B. , Al‐Juwair H. A. , Saafin A. K. 
Published: May 2005

AbstractParticle‐induced x‐ray emission (PIXE) and Rutherford backscattering spectromatery (RBS) were used to analyse desert rose geological samples. Samples from the rose core and from the rose peripherals were studied. All samples were found to contain C, N, O, Na, Mg, Si, S, Cl, K, Ca, Ti, Mn, Fe and Sr. Core samples were found to contain more silicon than peripheral samples. The extra silicon in the rose core may suggest a mechanism for the formation of the rose through crystal growth on a seed of silicon.
Application of a new treated LiF200 crystal to x‐ray fluorescence analysis of geological samples
Authors: Longerich Henry P. 
Published: May 2005

AbstractA LiF200 analyzing crystal, which was treated to enhance heavy element sensitivity, was evaluated for application to the analysis of geological silicate materials prepared as pressed pellets. The treated crystal produced up to two‐fold higher sensitivities along with backgrounds which were approximately two‐fold higher. Lower limits of detection were produced, and the treated erystal is recommended for the routine determination of the elements Ni through Nb using K emission and for elements having L emissions in the same energy range. The limit of detection for Nb was reduced from 0.9 to 0.6 ppm (100 s data acquisition) when the treated crystal was used in place of the standard crystal. For elements with lower emission energies, there was a smaller, but significant, lowering of the limit of detection when the treated crystal was used. The advantage of the treated crystal decreased as the emission energy decreased.
Review of recent applications of radioisotope excited x‐ray fluorescence
Authors: Valkovic V. , Markowicz A. , Haselberger N. 
Published: May 2005

AbstractRadioisotop‐excited x‐ray fluorescence is advantageously applied to many specific analytical problems. It is a method of choice for in situ and on‐line analysis. There is a growing need for in vivo determinations of many elements; radioisotope excitation offers some interesting possibilities. In addition to a review of published applications, current XRF activities in IAEA Laboratories are briefly described.
A simple model for optimization of conical capillaries in XRF analysis
Authors: Lindgren I. , Selin E. 
Published: May 2005

AbstractThe method of total reflection in conical glass capillaries has been used for several decades for obtaining high‐intensity x‐ray microbeams of small spot size. A general problem with this technique is the small critical angle, which is energy dependent. There is a certain loss of intensity if many reflections occur in the capillary. Assuming parallel monoenergetic x‐rays, a simple relationship has been derived for the intensity enhancement as a function of the reflectivity of the glass and the number of reflections. The relationship was used to derive conditions for optimum intensity enhancement. Also for suboptimum conditions the relationship can be used to design entrance and exit diameters and length of the capillary. The model was also applied to a wedge‐shaped slit that consists of two total reflection plates.