bluuebunny/crossref_metadata_2025 huggingface dataset:
A Review of the Relative Merits of Low Powered WDXRF and EDXRF Spectrometers for Routine Quantitative Analysis
Authors: Price B. J. , Padur J. , Robson N. S.
Published: March 2019

Historically, the development of XRF spectrometers has followed 2 main paths which are characterized by the means of spectral resolution they use. Those employing diffraction crystals and Braggs law to disperse the X-ray wavelengths are known as wavelength dispersive (WDX), whilst those usinq only the energy resolution of the detector, as enerqy dispersive (EDX). In the past these two have not normally been directly compared, because the WDX systems have always been the more expensive.
Imaging XPS. A Contribution to 3D X-ray Analysis
Authors: Ebel M. F. , Ebel H. , Mantler M. , Svagera R.
Published: March 2019

X-ray photoelectron spectrometry (XPS) has been a well established surface analytical technique for approximately 20 years. Fhotoelectrons are ejected by characteristic x-radiation. In our investigations we use Alκα-radiation. The depth from which l-l/e of the measured signal comes, is restricted to a few nanometers by inelastic mean free paths of photoelectrons in solids.
Niobium Concentration Measurement in Steel Samples with TXRF
Authors: Hegedüs F. , Winkler P.
Published: March 2019

In nuclear power plants the fast neutron fluence on the pressure vessel (PV) inner wall is measured by the scraping sampling method (1). As the inner plating of the pressure vessel contains 0.5 - 0.6 % of niobium, 93mNb (tt/2 = 16a) isomer is produced by the reaction 93Nb (n, n’). The activity of 93mNb is related to the fast neutron fluence.

Scraping samples (few hundred of mg) were taken from the PV inner wall. The niobium was chemically extracted from steel by using a HAP column. This extraction was needed to reduce matrix effects and to avoid interferences of other activities with 93mNb
Mass Absorption Coefficient Determination Using Compton Scattered Tube Radiation: Applications, Limitations and Pitfalls
Authors: Willis J. P.
Published: March 2019

Trace element determination by X-ray fluorescence spectrometry is subject, like almost all instrumental analytical techniques, to systematic errors, also known as matrix effects. This paper deals with the determination of mass absorption coefficients (MACs), using Compton peak intensities, for the correction of matrix effects arising only from elemental absorption in the sample.

When absorption effects are significant the relationship between net analyte peak intensity and concentration will no longer be constant, and corrections will be necessary for accurate analyses.
Secondary Target X-ray Excitation for In Vivo Measurement of Lead in Bone
Authors: Pella P. A. , Soares C. G.
Published: March 2019

Environmental lead exposure continues to be a health hazard, especially to young children, and is a serious problem In the U.S. Since lead is stored in the skeleton, measurement of lead in bone (e.g. finger or tibia) can serve as an Indicator of lifetime exposure. Energy-dispersive x-ray fluorescence (XRF) currently seems to be the method of choice for non-Invasive testing, and is expected to be further developed for screening purposes.
Non-Destructive Analysis of Venezuelan Artifacts of Different Sizes and Shapes for Provenance Studies
Authors: LaBrecque J. J. , Resales P. A. , Carias O.
Published: March 2019

Non-destructive analysis of Venezuelan pottery samples of different sizes and shapes from various archeological sites along the Orinoco River in the middle of Venezuela was performed by radioisotope X-ray fluorescence. The method employed a low intensity 109Cd source. The precision of the measurements for Fe, Rb, Sr and Zr from three different areas on each side of one of the artifacts was about 5%. A comparison of the data analysis using gross peak intensities and net peak intensities employing a digital filter technique to eliminate the background is presented. Finally an attempt to discriminate the samples of one location from another one or ones, assuming that the potter's clays were from different sources, is described.
Wide Angle and Small Angle X-ray Scattering Applications Using a Two-Dimensional Area Detector
Authors: Landes B. G. , Newman R. A. , Rudolf P. R.
Published: March 2019

The traditional medium for collecting two-dimensional x-ray scattering patterns is photographic film. While x-ray film has excellent resolution, several factors make it a poor choice as a detection device: slow speed, limited dynamic range, the “human factor” (developing, fixing, film handling), and the lack of a commercial scanning system designed for reading two-dimensional x-ray films. Until recently, there were no practical alternatives to the use of photographic film for obtaining two-dimensional x-ray scattering data using a conventional x-ray source. In the past few years, two different detection systems have become available for collecting high quality two-dimensional x-ray scattering data: (1) the Siemens (Xentronics) area detector system, which is a gas filled, wire grid detector, and (2) the Fuji imaging-plate system, which utilizes a phosphor storage plate for imaging the x-ray scattering and a laser scanner to process the image.
Quantification of Carbamazepine in Tablets by Powder X-ray Diffractometry
Authors: Suryanarayanan R.
Published: March 2019

A powder x-ray diffraction technique has been developed for the quantification of carbamazepine in tablets. The other tablet ingredients were microcrystalline cellulose, starch, stearic acid and silicon dioxide. The tablets were ground in a ball mill and the powder mixed with lithium fluoride (20% w/w) which was the internal standard. Five lines of carbamazepine with d-spacings of 3.38, 3.34, 3.28, 3.26 and 3.23 Å and the 2.01 Å line of lithium fluoride were used for the quantitative analysis. A plot of the intensity ratio (sum of the intensities of the lines of carbamazepine/intensity of die lithium fluoride line) as a function of the weight fraction of carbamazepine in the tablets resulted in a straight line. Using this standard curve, the carbamazepine content in “unknown” tablets was determined and ranged between 98.6 and 101.6% of the actual drug content. The coefficient of variation in the determinations ranged between 0.28 and 2.1%.
High-Temperature XRD Analysis of Polymers
Authors: Green Robert W.
Published: March 2019

High-temperature x-ray diffraction has many applications. Applied to polymeric materials it is a useful tool for investigating changes in crystallinity, providing insight into molding and extrusion problems, and for examining solvent-resistancy problems. An example of the increasing crystailine character of a polymer as a function of temperature can be seen in figure 1. Diffraction scans at 25°C, 100°C, 150°C, and 200°C clearly show the increasing crystalline character of the potymer with an increase in temperature. Control of sample temperature for a polymer is very important, when analyzing under air, because a momentary overshoot in temperature may lead to the sample igniting. High-temperature investigations of polymers are also subject to the problem of the sample warping and bowing.
Determination of Lattice Parameter and Strain of ϒ' Phases in Nickel-Base Superalloys by Synchrotron Radiation Parallel Beam Diffractometry
Authors: Ohno Katsumi , Ohsumi Kazumasa , Harada Hiroshi , Yamagata Toshihiro , Tamazaki Michio
Published: March 2019

The lattice parameters and strain of ϒ'-phase particles in Nickel-base superalloys, which are duplex type alloys designed for turbine blades and widely called “Ni-base single crystal superalloys”; they are accurately determined by Synchrotron Radiation parallel-beam diffractometry. The superalloys have ϒ' precipitates, an ordered FCC structure based on Ni3Al, in a γ-matrix having disordered FCC structure.

In addition, the preparation method of stress-free ϒ'-phase particles, with no composition change in the preparation process, was newly developed to measure the coherency strain of ϒ'-particles due to lattice misfit. The prepared ϒ'-phase particles are similar in composition and form to ϒ'-phase particles in the γ-matrices. The method for determining of the lattice misfit between the γ and γ’ particles was previously reported.
X-ray Residual Stress Measurement of Ground Surface of Metal-Ceramic Composite
Authors: Yajima Zenjiro , Hirose Yukio , Kishi Yoichi , Tanaka Kaisuke
Published: March 2019

Machine parts made of ceramics are usually finished by grinding. Residual stresses as well as defects introduced by grinding will influence the fracture strength and the function of the ceramic parts. Although several investigators measured the grinding residual stresses by the X-ray diffraction method, their grinding conditions were rather limited.
Interdependence of X-Ray Diffraction and X-Ray Fluorescence Data
Authors: Jenkins Ron
Published: March 2019

Current versions of the J.C.P.D.S. Powder Diffraction File Include some 26,000 standard patterns and this number is Increasing at the rate of around 1500 patterns per year. Although the actual number of patterns still represents a relatively small fraction of the total number of phases possible, it does include the majority of well known phases. A variety of search/match schemes have been designed under the auspices of the Joint Committee on Powder Diffraction Standards and these include data retrieval methods based both on hand and computer searching.

Since the majority of analytical problems involve multiphase materials, one of the greatest problems in qualitative identification is the “unscrambling” of the various phase patterns to allow matches to be made with standard patterns of pure materials.
Analysis of Agglomerate and Slag by Energy Dispersive X-Ray Fluorescence
Authors: Ratyński W. , Cieślak E. , Karwowski H. , Parus J. , Tys J. , Dworak B.
Published: March 2019

A rapid analytical procedure for simultaneous determination of Ca, Mn and Fe in agglomerate and slag has been developed.

A 100 mCi annular source of 238Pu has been used for excitation and Si(Li) detection system with ADC coupled with minicomputer for data acquisition and processing. A modified Heinrich-Rasberry procedure has been applied for analytical results evaluation. The measurement of each sample consumes about 100 s and the data processing time is 20 s approximately. The peaks were integrated in a fixed number of channels and linear background was subtracted. Seven standard samples both of slag and agglomerate have been used for system calibration.
Spectrochemistry in the Iron Foundry: X-Ray Fluorescence vs. Optical Emission
Authors: Gast Richard
Published: March 2019

The casting of iron is largely a chemical process: that is, the chemistry of molten iron greatly influences the properties of finished castings. Other parameters - casting design, mold integrity, inoculation practice, pouring temperature, and shakeout procedure - are also vital to consistent production. But if the chemistry is wrong, the probability of defective castings is high. For this reason, control of chemical composition has long been a major objective of foundrymen.

To be useful for either process control or quality assurance checking, analytical work must be reliable and accurate. Data should also be available in a minimal period of time to make possible the on-line adjustments necessary to achieve proper chemistry, and thus the desired properties, in the final castings.
X-Ray Fluorescence Capabilities for Uranium Ore Analysis
Authors: Nielson K. K. , Wogman N. A. , Brodzinski R. L.
Published: March 2019

Comparable uranium sensitivities and detection limits can be obtained by either energy- or wavelength-dispersive x-ray fluorescence (XRF) analysis of L x-rays, and by wavelength-dispersive analysis of M x-rays. XRF methods are more sensitive than 252Cf neutron-induced γ-ray analysis or direct photon analysis of rapid-equilibrium uranium daughters. A laboratory method is demonstrated for quantitative uranium determination in unknown geological matrices without using ore standards.
Determination of Uranium in Carbonate Solutions by Extraction onto a Chemically Modified Surface
Authors: Jablonski Bruce B. , Leyden Donald E.
Published: March 2019

Silica gel treated with a commercial silylation reagent (Dow-Corning Z-6020) has been found to extract uranium from carbonate solutions. The materials used are simple to prepare and once the uranium is extracted, x-ray fluorescence may be employed to determine the uranium directly on the solid. A dependence of the extraction upon carbonate concentration is observed. A lower limit of detection of 2.46 μg of 0.12 ppm uranium from a 20 ml sample is obtained.
A New Device for the Precise Measurement of X-Ray Attenuation Coefficients and Dispersion Corrections
Authors: Creagh D. C.
Published: March 2019

Results of measurements of the mass attenuation coefficients (μen/ρ) and the dispersion corrections f’ and f” have been given in two recent papers. The data cited in these papers were gained using both a conventional XRF spectrometer and a multiple reflection double crystal spectrometer based on the Bonse-Hart low angle scattering camera. Both of these techniques have deficiencies which limit their usefulness in operation. The XRF technique has been shown to become inaccurate for thick specimens. The multiple reflection spectrometer experiences alignment and stability problems, because, for each wavelength, three different axes must be adjusted. Since the angle of acceptance of the grooved multiply-reflecting elements is less than 10 seconds of arc, any misalignment of one element of the spectrometer with respect to the other causes large variations in the intensity of the beam transmitted through the spectrometer.
Evaluation of Pulse Pileup Rejection
Authors: Russ John C. , Sandborg Alan O.
Published: March 2019

Comparisons of energy- and wavelength-dispersive spectrometry inevitably focus on the count rate limitations of the ED electronics. In some cases the use of amplifiers without pulse pileup rejection, or worse, misadjusted pileup rejection circuits, has led to erroneous results and assumptions regarding maximum tolerable count rates which are far too low.

Proper evaluation of pileup rejection must consider both the count rate and energy dependence of the circuits. For example, using a typical ED spectrometer (EDAX, 154 eV, 10 mm2, 6 μsec amplifier time constant) we can first measure the total amplifier throughput curve as shown in Figure 1. This curve is only slightly dependent on photon energy, at least over the range from about 1-10 keV which usually contains the major part of the X rays, and shows a maximum stored count rate of slightly over 3000 cps for an input count rate of slightly less than 10,000 cps. Changing the amplifier shaping time constant will change the scale of the curve, but not its general shape.
Frequency Shift of L-Valence Band Spectra of Niobium and Tin in Nb3Sn Compound
Authors: Wald S. S. , Cheng S. K.
Published: March 2019

Soft X-ray L-emission spectra of tin in second order diffraction and of niobium in first order have been studied in pure elements, in oxides, and in intermetallic Nb3Sn compound.

The study was done by a newly designed soft X-ray vacuum spectrograph. The curved crystal spectrograph is of the Johann type mounting. The radius of curvature of the bent crystal was 50.8 cm. The essential parts of the instrument are (i) an interchangeable bent crystal holder so that the spectrograph can cover a wide range of energy spectra by using crystals of different d-spacings to obtain highest resolution for the particular wavelength range; (ii) an adjustable Hartmann slit to control the effective width of the bent crystal; (iii) a half-shadow device to take two spectra onto the same film in the lower and upper half of the film; (iv) a sharp edge metal fixed to the Rowland circle to obtain a fiducial mark on the film; (v) a water-cooled rotatable Cu anode target; and (vi) a filament with both translational and rotational freedom to ensure optimum beam focusing.
Elemental Analysis of Biomedical Samples by Pixe
Authors: Guffey J. A. , Van Rinsvelt H. A. , Adams W. R. , Sarper R. M. , Karcioglu Z. , Fink R. W.
Published: March 2019

The use of particle-induced X-ray emission (PIXE) analysis as a standard analytical tool in the study of trace elements is well known. In the present investigation, an attempt is made to correlate human diseases with the presence or absence of trace elements and/or the changes in their concentration in healthy and diseased tissues. If such correlations do actually exist, trace element analysis could certainly be used as a diagnostic tool for the early detection of diseases and there is considerable interest in such information.
Optimal Calibration Curves for Guinier-Type Focusing Cameras
Authors: Brown Allan
Published: March 2019

The inclusion of an internal calibrant in specimens prepared for Guinier-type focusing cameras is a well-established practice. The true reasons for performing calibration are, however, not always clearly understood. Accordingly, procedures adopted on the basis of this calibration for converting distances measured on the film into reliable values of θ vary in detail from one laboratory to another. The possibility that calibration curves can exhibit different degrees of reliability, depending upon camera alignment, is even less generally appreciated. The following account records efforts made over the years to come to terms with these problems in order to obtain unit cell dimensions at the 0.01 % level of precision from the routine measurement of Guinier diffraction patterns.
Software for XRF
Authors: Mantler Michael
Published: March 2019

As in other fields of spectroscopy, software for x-ray fluorescent analysis has to assist the user in instrument control, raw data refinement, qualitative interpretation of spectral data, and computations for obtaining quantitative results. From a historical point of view, instrument automation and data evaluation routines tor large numbers of samples have been a most important incentive for the introduction of computers into x-ray analysis.
Applications of Whole-Powder-Pattern Fitting Technique in Materials Characterization
Authors: Toraya Hideo
Published: March 2019

The development of powder-pattern-fitting techniques greatly changed the methodological aspect of materials characterization using powder diffraction data. Pencil and ruler are going out of use in modern powder data analysis, and present-day materials scientists hit a keyboard and manipulate a mouse of computer for deducing the final parameters of the model, which gives the best fit of calculated pattern to the observed one on a CRT screen. Computer software is now widespread, and the success in materials characterization becomes much dependent on their availability.
Stress-Depth Profiles in Magnetron Sputtered Mo Films Using Grazing Incidence X-Ray Diffraction (GIXD)
Authors: Ballard B. L. , Predecki P. K. , Braski D. N.
Published: March 2019

Intrinsic stresses as a function of σ, the 1/e penetration depth were measured for a smooth, 1μm thick, fine grained, cylindrical post magnetron sputtered molybdenum film deposited on a vycor glass substrate in the dynamic deposition mode. Using grazing incidence diffraction and the Mo (321) reflection, lattice spacing profiles were determined for τ values from 200-4400 Å. The in-plane intrinsic stresses parallel and perpendicular to the post axis were determined employing the ϕ-integral method and assuming elastic isotropy. The results were related to the surface structure and composition profiles via atomic force microscopy (AFM) and auger electron spectroscopy (AES) respectively.
Resolving Common Element Problem by Using Different Lines in Fundamental Parameters Method Multilayer Thin Film Analysis
Authors: Feng Liangyuan
Published: March 2019

The presence of one or more common elements in different layers often complicates or hampers the analysis of a multilayer thin film system. Some constraints or preconditions are usually required in order to reach a mathematical solution. For example, either the concentration(s) of the common element(s) in, or the thickness(es) of one of the relevant layers must be known.

An alternative approach is the use of more than one analyzing line for the element in question. Although this approach has long been proposed, there have been no detailed studies seen in literature. An attraction of using this approach is that it requires no prior knowledge of either the concentration or the thickness. The author has implemented this approach, and studied in detail its feasibility and pitfalls for practical applications.
High Accuracy Analysis of BPSG Thin Films on Silicon Wafers by X-Ray Wafer Analyzer
Authors: Kohno H. , Arai T. , Araki Y. , Wilson R.
Published: March 2019

The wafer analyzer has been used to fulfil many applications needs in the semiconductor industry. The prominent features of the XRF method for the semiconductor industry are:analysis of many types of films, e.g., oxides, silicides and metallic alloys, and simultaneous analysis of film thickness and compositions.

In the past, the analysis results of BPSG (Boron-doped Phospho-Silicate Glass) films, with thicknesses greater than 4000 Å, were reported. With the recent increased demand for larger scale and higher quality semiconductor devices (larger than 64 Mbit), more accurate analysis with high precision has been required.
Evaluation of σ33 From Diffraction Experiments Performed With Synchrotron Radiation in the Ω - and Ψ - Goniometries
Authors: Detempte I. , Ruppersberg H.
Published: March 2019

A formalism which was proposed by Ruppersberg (1992) for a self consistent evaluation of stress gradients in the case of strongly varying σ33(T) stresses is applied for studying the variation of the stress components with distance z from the irradiated surface of a ground hardened steel plate.
Methods for Depth Profiling Complete Stress Tensors Using Neutron Diffraction
Authors: Winholtz R.A. , Krawitz A.D.
Published: March 2019

Neutron diffraction has proved to be a useful tool for measuring residual and applied stresses in materials. Aspects of experimental design and methods for the mapping of complete triaxial stress tensors in a large component are discussed in the context of a comprehensive set of stress measurements made within the interior of the circumferential weld on a 0.91 m diameter cylinder. The cylinder is a subscale model of the casings for the Advanced Solid Rocket Motor being designed for the space shuttle. The subscale model was fabricated in order to characterize the residual stresses created in the welding process and to determine the effect of post weld heat treatment on the residual stresses. Control of the residual stresses in this application is necessary to eliminate possible problems with stress corrosion cracking in a salt water environment. Some illustrative results are also presented.
Measurement of X-Ray Elastic Constants From Ground Ceramic Showing Non-Linear Sin2ϕ Diagrams
Authors: Ohtsuka Masaaki , Matsuoka Hideaki , Hirose Yukio , Ishii Hitoshi
Published: March 2019

Machined parts made of fine ceramics are usually finished by grinding (Yajima et al.,1990, Mishima et al.,1987). The residual stress introduced by grinding will influence the fracture strength and the function of ceramics, and needs further consideration. Over the past few years, a considerable number of studies have evaluated ground ceramics by means of the X-ray method. However, it is well known that X-ray stress measuring data, 2 θ φ φ-sin2 φ curves of the surface layer of the unidirectionally machined ceramics are showing non-linear behavior (Kishimoto et al.,1987) . In this case, the sin2 φ method is inadequate for the evaluation of the stress (Sasaki et al.,1989).
Thickness Gauging of Organic Films on Large Plastic Body Parts With an Xrf Probe Based on a Roomtemperature Mercuric Iodide Detector
Authors: Buckens Pierre F. , Iwanczyk Jan S. , Wang Yuzhong J. , Marano Richard S.
Published: March 2019

The variability of adhesion promoter (primer) film thickness has been identified at Ford Motor Company as an important factor in maintaining the quality of paint on exterior plastic body parts. XRF offers unique advantages for non-destructive film monitoring. Monitoring of large parts for process control requires a non-contact approach using a small mobile probe. Previous attempts to implement a practical XRF gauging probe have been hampered by the choice of available x-ray detection technologies; proportional counters cannot resolve the layer's fluorescent lines properly and suffer from instability, while Si(Li) or Ge detectors need cooling to low temperatures, which makes their usage impractical for mobile probe.

The recent commercial availability of state-of-the-art Mercuric Iodide (HgI2) x-ray detectors led to the development of a lightweight XRF probe that contains an x-ray tube and a HgI2 detector. Thickness measurements of primer films on plastic substrates were characterized, and 15 sec. acquisition yielded precision of 0.225 and 0.525 pm for film thicknesses of 5 and 20 µm respectively. Ti was added to the substrate and Cr to the film as tagging elements. A ratiometric technique, taking into account absorption of the Ti signal in the film, yields excellent linearity and compensates for instrumental errors such as sampleto- probe distance variation and x-ray source fluctuations.
High-Pressure Powder Diffraction Using an Image-Plate Area Detector
Authors: Nelmes Richard J. , McMahon Malcolm I.
Published: March 2019

Modern synchrotron sources, and recent developments in experimental techniques, are allowing significant: progress to be made at present in the quality of crystal-structure infonnation at high pressure. Though there are exciting prospects for single-crystal work, especially using Laue techniques, most of the recent advances have been made in powder diffraction. In any case, high-pressure diffraction studies often require powder techniques because single crystals fail to survive the large density changes that accompany many pressure-induced phase transitions. In this paper, we focus on angle-dispersive (AD) powder diffraction on synchrotron sources.
Measurements of the Thermal Expansion Of Materials with High Melting Points by X-Ray Diffraction
Authors: Ebner Richard , Mantler Michael , Hoch Michael
Published: March 2019

X-ray diffraction at temperatures above 2500K gives rise to a wide variety of problems. Not only is there the sample to be heated but also the attachment must be cooled properly, the sample's temperature to be measured and last but not least the sample evaporation to be considered, which sets a limit to the maximum temperature to be reached. There are still other factors limiting the specimen temperature, e.g. an emissivity of the specimen higher than that of the heating strip, a good electicai conductivity or a good thermal conductivity of the specimen material. All these influences were investigated in [1].
In Situ X-Ray Diffraction of an Arc Weld Showing the Phase Transformations of Ti and Fe as a Function of Position in the Weld Performed at a Synchrotron
Authors: Wong Joe , Elmer J. W. , Waide P. A. , Larson E. M.
Published: March 2019

The synchrotron x-ray source provides a unique opportunity to observe many “in-situ” processes. The formation of the “short-lived” intermediate species, Ta2C, during the combustion synthesis of TaC, has been observed and reported by monitoring the Bragg diffraction peaks of the reactants and products, Similarly, the synthesis of the ferroelectric material, BaTiO3, and subsequent phase transfonnation from cubic to tetragonal have also been investigated. These experiments would not have been possible without the high incident x-ray flux available at a synchrotron source.
Characteristics of New Pyrolitic Graphite Crystal for X-ray Diffraction and Fluorescence Analysis
Authors: Ohno Katsumi , Murakami Mutsuaki , Hoshi Toshibaru , Kobayashi Yuji , Shoji Takashi , Arai Tomoya
Published: March 2019

A highly oriented pyroliiic graphite crystal is commonly used as a monochromator for X-ray diffraction and fluorescence analysis (l)-(6). Improvements in the monocliromator performance is desired to increase the range of practical applications.
TXRF High Sensitivity X-Ray Analyzer With Multi-Layer Monochromator
Authors: Utaka T. , Shoji T. , Shimizu K. , Arai T. , Wilson R.
Published: March 2019

Total reflection X-ray Fluorescence (TXRF) has been applied to the detection and quantification of metal contamination on the surface and near-surface regions of silicon wafers in the semiconductor industry The need for improving the sensitivity and detection limit of the TXRF technique is driven by the progress in producing thinner films and finer features in the development of larger Mbit DRAMS.
Matrix Correction With Barkla Excitation Using the Coherent/Incoherent Method
Authors: Swoboda Walter , Beckhoff Burkhard , Kanngieβer Birgit , Scheer J.
Published: March 2019

The scattering of the primary X-ray tube spectrum on a low Z material in 90°-geometry produces polarised excitation radiation, which clearly decreases the background of fluorescence spectra in Cartesian geometry (Barkla excitation). Several publications have shown the advantages of this excitation mode in comparison with both direct excitation and secondary target excitation.
Investigation Of Geometrical Effects in X-Ray Microfluorescence Analysis of Geological Samples
Authors: Lankosz Marek , Pella Peter A.
Published: March 2019

Geometrical effects occur when primary x-rays irradiate a mineral inclusion which lies close to the boundary between it and a surrounding mineral having a different chemical composition. An investigation of one of these near-edge effects was performed in the case when x-ray microfluorescence is applied for analysis. Analytical mathematical expressions were developed to correct for this effect and were tested exper imentally.
Measurement Of Relative X-Ray Intensity Ratios for Elements With Z=14 to 92 Using EDXRF Spectrometer
Authors: Stoev Krassimir N. , Dlouhy Joseph F.
Published: March 2019

Nowadays x-ray fluorescence analysis is one of the major techniques for determination of trace elements. Vacuum operated Si (Li) .energy-dispersive x-ray spectrometers can analyze simultaneously up to 50 elements from Na (Z=11) to U (Z = 92) . Proper interpretation of the accumulated spectra requires correct solution of x-ray line overlap problems. In many cases knowledge of x-ray intensity ratios can make the procedure for resolving the overlapped peaks more reliable and reproducible. Measurements of radiative transition rates can also provide fundamental tests of theoretical atomic structure calculations. There are many other useful applications of x-ray emission rates in theoretical and experimental physics. On the other hand, there are differences in the published data, which suggests that x-ray intensity ratios are still not known with the necessary accuracy, and new measurements are useful and necessary.
Computerized X-Ray Data Periodic Table
Authors: Stoev Krassimir N. , Dlouhy Joseph F.
Published: March 2019

Nowadays personal computers [PCs) have sufficiently high speed of calculation and large memory and can be used for precise modeling and implementation of the fundamental parameter methods in the x-ray fluorescence (XRF) analysis. Because of its low price the PC is generally a standard component of energy-dispersive and wavelength-dispersive x-ray fluorescence analyzers, and allows not only automation and control of the whole spectrometer during the scientific experiments or routine analysis, but also complete on-line calculation of concentrations {using sophisticated calibration models), QA/QC monitoring, and archivation of the data. Together with the development of faulti-task operation systems for personal computers the efficiency of their use became higher. A few years ago the main requirement for the software was that it be optimized in order to perform many sophisticated calculations in as short time as possible, and less attention was paid to the interface “computer-user”. Now, with much more powerful new generation PCs, one of the main requirements on the software for XRF analysis is to be “user-friendly”, i.e. not to require special education and extended learning period before using it and to ensure high flexibility of application of the programs.
Special Problems in Forensic Materials Analysis by XRD
Authors: Camp Michael J.
Published: March 2019

There are three factors which may influence the method by which a piece of evidence is analyzed in a forensic laboratory. The first stems from the definition of the word forensic. It means ”… pertaining to, connected with, or used in the courts of law…” The major areas of forensic analysis are criminal, regulatory, and civil. The purpose of an analysis may be to aid in the prosecution or defense of criminal charges, to determine if a product meets its statutory requirements, to satisfy a consumer complaint, or to determine liability. For these reasons the legal aspects of an analysis may often put constraints upon the analyst. These may require special handling or documentation procedures.
Identification of Multiphase Unknowns by Computer Methods: Role of Chemical Information, the Quality of X-Ray Powder Data and Subfiles
Authors: McCarthy Gregory J. , Johnson Gerald G.
Published: March 2019

Three variables in the identification of crystalline multiphase unknowns by computer search/match methods were examined: presence or absence of chemical information; varying quality of d-I diffraction data; use of a large data base vs a data base having about 10% as many entries--both contain the unknown phases. The results showed that the search/match using average quality d-I data with chemical information was quite successful, while that obtained using higher quality d-I data alone missed one of four phases. It took only half the time to obtain the average d-I data plus chemistry as it did to obtain the higher quality data. Searching the smaller data base with the higher quality data alone resulted in an identification of all phases with high reliability.
Application of Guinier Camera, Microcomputer Controlled Film Densitometry, and Pattern Search-Match Procedures to Rapid Routine X-Ray Powder Diffraction Analysis
Authors: Edmonds J. W. , Henslee W. W.
Published: March 2019

In most routine chemical analyses, a trade-off is made between quality of data and time required to obtain and analyze the data.In X-ray powder diffraction, identifications are normally made by Debye-Scherrer film methods or by medium speed (1-2°20/min.) diffractometry, with or without an internal standard. With one notable exception, the inherent precision of the Guinier camera geometry has been virtually ignored as too expensive or time consuming for routine work, or relegated to special projects. The accessibility of microcomputers, however, not only makes it economically and realistically feasible to automate the equipment previously used for special Guinier projects, but to extend the overall precision of observed d-spacings into the area of routine analysis. Search-match procedures benefit from the increased data precision to such an extent that they can be used routinely to propose the identity of major pure phases and release the analyst to concentrate on minor components and impure phases which may be subject to lattice constant shifts.
X-Ray Powder Diffraction Investigation of the Monumental Stone of the Gastel dell'Ovo, Naples Italy
Authors: Lewin S. Z. , Charoia A. E.
Published: March 2019

The Castel dell'Ovo on the Bay of Naples, Italy, is an important historic structure dating from the 12th century. It is composed of a soft, volcanic tuff that was employed because it was locally available and easy to quarry and work. The exposed stone of this monument shows extensive decay, principally in the form of the crumbling away of the surface, and this has progressed to the greatest extent in the lower parts of the structure. Restoration and preservative intervention are now being considered. The essential prerequisites to the formulation of a safe and effective strategy of treatment of the monument are the understanding of the nature and properties of the stone, and of the factors responsible for its decay. The present investigation was undertaken to provide that information. In the course of these studies certain novel and significant features of the crystal chemistry of one of the common zeolite minerals have been observed, and are reported here.
A New Method for Fast XRPD Using a Position Sensitive Detector
Authors: Göbel Herbert E.
Published: March 2019

The scanning speed of powder diffractometers can be increased by about two orders of magnitude by replacing the normal detection system (receiving slit/scintillation counter) by a linear position sensitive detector (PSD) which collects diffracted x-rays of a larger part of the diffractometer measuring arc simultaneously. The velocity increase is proportional to the section of the arc 29 in which the diffracted x-rays are detected. With respect to the Bragg-Brentano focussing geometry, a range of several degrees (typically 5°) can be tolerated without affecting the resolution remarkably. Diffractograms over extended angular regions of 2θ are received by slewing the PSD continuously along the arc while the diffracted x-rays are accumulated with their accurate 2θ angle address on a digital base.

The method has been named the continuous position sensitive detection technique (CPSD). With this technique, diffraction patterns with similar quality (resolution, linearity, peak/background ratio) as conventional, scintillation counter recorded diagrams can be received at slewing rates of several hundred degrees per minute. Additionally, the CPSD technique augments the number of crystallites contributing to the diffraction intensity by the same amount, thus producing much better crystallite statistics for quantitative measurements.
The Resolution of X-Ray Fluorescence Spectra by the Least Squares Method
Authors: Sanderson Colin G.
Published: March 2019

Least squares computer programs have been used for the resolution of complex gamma-ray spectra obtained from NaI(Tl) detectors for many years. With the addition of computer codes, which account for the differences “between gamma-ray and x-ray fluorescence spectra, these same programs can be used to quantify energy dispersive x-ray fluorescence data.
Modelling Intensity and Concentration in Energy Dispersive X-Ray Fluorescence
Authors: Shen R.B. , Russ J.C. , Stroeve W.
Published: March 2019

It might seem at first glance that quantitative models relating intensity to concentration should be identical for energy - or wavelength - dispersive fluorescence analysis. In both cases the interelement effects that complicate the use of simple linear calibration curves occur in the specimen, at which time the X-rays are not yet aware of which kind of detector will be used to count them. This can be true in some cases, but not in general.
Automated Determination of Optimum Excitation Conditions for Single and Multielement Analysis with Energy Dispersive X-Ray Fluorescence Spectrometry
Authors: Wegscheider Wolfhard , Jablonski Bruce B. , Leyden Donald E.
Published: March 2019

The determination of optimal excitation conditions for energy dispersive x-ray fluorescence is particularly critical for multielement analysis covering a wide range (viz. 10 or 20 keV) of the spectrum. Functions that quantitatively describe the spectral quality are used as objective functions in pattern search algorithms. It is shown that the filters can be arranged in a definite order, at least with respect to the energy of the K-absorption edge of the tube and can therefore be employed as a dimension in the optimization process. Of the algorithms that were compared, the Nelder-Mead and Routh-Swartz-Denton versions of the sequential simplex search gave the best results if the excitation voltage and the current could be controlled in small increments. If the optimization includes dimensions with a few discrete stages (e.g. filters) the fixed size simplex proved to be of greatest value. The functions can be weighted to reflect special interest in one or more elements. Conditions for increasing the counting time and terminating the search are discussed.
Some Studies of Chlorinated Poly(Vinyl Chloride) Using X-Ray Photoelectron Spectroscopy
Authors: Gianelos James , Grulke Eric A.
Published: March 2019

Chlorinated poly(vinyl chloride) (CPVC) is similar in many ways to its thermoplastic parent poly(vinyl chloride) (PVC), Chlorination imparts superior high temperature properties, which make CPVC preferable for many and varied applications.

Our primary purpose in studying CPVC with x-ray photoelectron spectroscopy (XPS) was to see whether we could gain insight into how chlorine substitutes into the PVC molecule. We also hoped we would obtain insights into the chlorination reaction itself, and how variations would affect the final product.
Presentation of the J. D. Hanawalt Award
Authors: Hanawalt J. D.
Published: March 2019

First, let me say that I am deeply honored by the action of my friends of the Joint Committee in establishing the Hanawalt Award. I have greatly enjoyed my association over the years with the members of the Joint Committee, So many brilliant and talented people have contributed so much to the work of the Joint Committee, By comparison, my contributions have been minor and I feel very humble to be so honored. I want to thank you all for your part in the proceedings today. It is a very high point in my life.
A Combined Derivative Method for Peak Search Analysis
Authors: Huang T. C. , Parrish W.
Published: March 2019

A comprehensive study of derivative methods for the peak search analysis of X-ray diffraction data was made to determine the relative merits of the methods. The peak positions were best determined by the cubic first derivative method which had an intrinsic error ≤ 0.001°, and random error ∼ ± 0.003 ° to 0.02 ° depending on the counting statistical noise. The quadratic/cubic second derivative method had the highest resolution with a separation limit ≥ 1/2w (w = full width at half maximum). An effective algorithm combining the cubic first derivative and the quadratic/cubic second derivative methods was developed for high precision and resolution. The method uses a full screen menu for parameter selection, and the entire peak search analysis including peak identification and position determination, and graphic and numeric display of results at the color terminal is completed in a few seconds using a time sharing mode on an IBM 3083 central processing unit. The combined derivative method should be also applicable to other spectra such as gamma-rays, X-ray fluorescence, optical, infrared, ESCA, Mossbauer, etc.
X-Ray Multiaxial Stress Analysis Taking Account of Stress Gradient
Authors: Sasaki Toshihiko , Kuramoto Makoto , Yoshioka Yasuo
Published: March 2019

Since the method of X-ray multiaxial stress analysis (ψ-splitting problem) was proposed by Dolle and Hauk, their method is often utilized for residual stress evaluation on a processed surface. However, as pointed out by thanselves, a theoretical problem still remains on the assumption of the stress state. Namely, the effect of ψ-splitting is impossible unless stress gradients with respect to the direction of the depth in σ13 or σ23 are present, because these components and σ33 have to vanish at the outer surface. Actually, we often find the 2θ vs. sin2ψ relations which do not agree with their theory. In this paper, we proposed a new method for X-ray multiaxial stress analysis in which the effect of stress gradient was considered. The basic equation of this method was solved by means of the integral method proposed by Lode and Peiter. The validity of the present method was proved through a numerical simulation and an experiment.
On the use of Synchortron Radiation for the Study of the Mechanical Behaviour of Materials
Authors: Barral Marc , Sprauel Jean-Michel , Lebrun Jean-Lou , Maeder Gérard , Megtert Stephan
Published: March 2019

The study of the mechanical behaviour of materials by X-ray measurements in a classical laboratory is limited by the possibilities of the X-ray tubes used. Some crystallographic planes are not conducive to good diffraction conditions and the radiation characteristics' may not be optimum. The use of synchrotron radiation resolves many of these problems by providing a continuously variable wavelength which allows measurements of stress and stress gradients to be carried out in very good conditions. The high intensity and perfectly monochromated radiation with a small beam divergence are very helpful for microstrain measurements.
A Miniature Instrument for Residual Stress Measurement
Authors: Ruud C. O. , DiMascio P. S. , Snoha D. J.
Published: March 2019

The Pennsylvania State University has developed and tested a miniature x-ray instrument for the measurement of residual stress (strains). The stress head including x-ray source and detection surface is approximately four and one-half inches long and can be inserted into an orifice less than two and one-half inches in diameter. This head is on the end of a several-foot long cable and is extremely manipulatable.

The instrumentation design is based upon a unique position sensitive scintillation detector which ie capable of applying the single-exposure x-ray stress measurement technique. Total lapse time data collection periods for aluminum alloys are less than ten seconds with x-ray tube powers of 120 watts. Results from a four-point bend test on an aluminum alloy specimen showed excellent precision. The configuration of the instrument and the procedures for its application are described.
A Low-High Temperature Camera for In-Situ X-Ray Diffraction Studies of Catalysts
Authors: Pielaszek J. , Cohen J.B.
Published: March 2019

X-Ray diffraction studies of substances under controlled atmospheres and at different temperatures are of great importance in many research areas. This is especially true in the area of catalysis, where the correlation of structural and catalytic properties is needed. The camera described here was made for this purpose although any sample in the powdered form can be studied as well. Many catalysts are in the form of highly dispersed metal deposited on a granulated support. The content of metal may vary from a few tenths to several percent. In a camera used by Janko and Borodzinski a small amount of catalyst was spread out on a porous silica glass sample holder which then was placed in a high temperature XRD camera with flowing gas of controlled composition.
Quantitative Analysis: A Comparative Study Using Mo and Cu Radiation on Coal Related Minerals and Fly Ash
Authors: Amenson J. , Benson J. , Demirel T. , Jacobson R.
Published: March 2019

Our experience using Mo Kα radiation in coal related research indicates that minerals can be detected and quantitatively measured at the 0.2% level in an amorphous substance such as coal. Since the linear absorption coefficient for most elements is about a factor of eight lower for Mo radiation than it is for Cu radiation, the matrix affect is greatly reduced and the intensity is a more linear function of concentration.

Although there is considerable overlapping of peaks when complex mixtures are analyzed using Mo radiation, the use of second derivative techniques to locate peaks, and least squares techniques to fit peaks can resolve many of these problems. The reduced time needed to collect a diffraction pattern, and the increased intensity obtained more than compensate for the extra computer time needed to analyze the data.