bluuebunny/crossref_metadata_2025 huggingface dataset:
The Choice of Lattice Planes in X-Ray Strain Measurements of Single Crystals
Authors: Ortner Balder
Published: March 2019

It is well known that all of the six independent components of the strain tensor can be calculated if the linear strains in six appropriate directions are known (e.g.). That calculation is to solve a system of linear equations, whose coefficients are defined by the orientations of the measured planes. The strains are determined by lattice plane distance measurements using X-rays.

The linear equation system can only be solved if the matrix of coefficients has rank. Whether this condition is met or not can be decided without calculating a determinant just from geometric relationships among the planes to be measured. A demand beyond that necessary condition is to make the matrix of coefficients so that the accuracy of the calculated strain tensor is best. From error calculation we know that there exist distinct ratios between the inevitable measurement errors and the errors of the calculated strain components. These ratios depend strongly on the geometric relationship among the lattice planes. It is the purpose of this paper to show how lattice planes should be chosen in order to get these ratios as small as possible i.e. to get a maximum of accuracy at a given number of measurements, or a minimum of experimental effort if a distinct limit of error is to be reached.
Computer Capability for the Determination of Polymer Crystallinity by X-Ray Diffraction
Authors: Wims Andrew M. , Myers Mark E. , Johnson Jack L. , Carter Julia M.
Published: March 2019

The physical and mechanical properties of many industrially important polymers are profoundly influenced by their degree of crystallinity; such properties include flex modulus, tensile strength, percent elongation, and impact strength. Commonly used polymers influenced by their crystallinity level include polyethlene, polypropylene, polyesters, and nylons. Many of these materials are above their glass transition temperature at room temperature and would be useless were it not for their crystalline phase which typically has a melting point far above room temperature. The crystalline ‘ regions (domains) in these materials are frequently very small, typically in the nanometer range in diameter. These crystalline domains act as reinforcing fillers (in somewhat the same manner as carbon black In rubber) and give strength to the polymer.
Measurement of Elastic Lattice Distortion in PbTe/PbSnTe - Strained Layer Superlatices by Asymmetric High Angle X-ray interfernces
Authors: Fantner E. J.
Published: March 2019

Elastic strain significantly affects the electric and optical properties of PbTe/Pb1-xSnxTe - strained-layer superlattices. In the range of 10 - 350K the temperature dependence of the elastic strain present in these superlattices was measured by double-crystal x-ray diffraction. For superlattice periods smaller than 100nm High-angle x-ray interferences were observed. Using a novel method, which makes use of the High-angle interferences both for symmetrical as well as for asymmetrical reflections in a theta-twotheta scan with a narrow detector slit, the relative inclination of equivalent lattice planes due the elastic strain was measured. The components of the complete strain tensor of the constituent layers can be determined seperately even if their unstrained lattice constants are not known with sufficient accuracy as is the case in ternary and quaternary compounds. The lattice mismatch of up to 0.4% for Sn-contents smaller than 20% was found to be accommodated almost completely by elastic misfit strain. The amount of strain is shared between the constituent layers inversely to their relative thicknesses as long as the superlattice as a whole is much thicker than the buffer layer. Below room temperature an additional temperature dependent tensile strain due to differnt thermal expansion coefficients of the film and the BaF2-substrate is measured quantitatively.
Characterization of Tungsten Silicide and Titanium Silicide Thin Films With a Fully-Automated See Mann-Bohlin Diffractometer
Authors: Matyi R. J.
Published: March 2019

The continuing drive in the semiconductor industry towards smaller and more complex electronic devices has placed increasing severe demands on the materials systems that are used in semiconductor circuits. The refractory metal silicides that are commonly used for electrodes and interconnects are particularly susceptible to the sometimes conflicting requirements of good electrical properties, ease of processing, and long term reliability. We have found that the characterization of metal silicides with a fully automated diffractometer based on the Seemann- Bohlin (S∼B) focusing geometry has proved to be an important aid in the development of several semiconductor metallization systems.

Although a conventional Bragg-Brentano (B-B) diffractometer can provide adequate information for some thin film systems, the use of an S-B diffractometer in which the incident x-ray beam makes a very small angle of incidence with the sample surface results in a substantial improvement in the usable signal from very thin samples.
An X-Ray Micro-Fluorescence Analysis System With Diffraction Capabilities
Authors: Nichols M. C. , Ryon R. W.
Published: March 2019

A prototype X-ray fluorescence system for chemical and phase microanalysis of materials has been developed and tested. Preliminary work with this system has indicated X-ray fluorescence detection limits on the order of 40 picograms for heavier elements such as gold when using a 100 micron collimator, 400 second counting time and a silver anode operating at 12 Kw. Phase identification by X- ray diffraction can be obtained from the same spot. A proposed design for an improved system providing greater elemental sensitivities and capable of semi-automated operation has been completed.
Detection of Single Ions by Fulse Counting: Application to Ion Microprobe Mass Analyzer
Authors: Dietz L. A.
Published: March 2019

The need to detect low intensity beams of resolved ions with keV energy is encountered frequently in mass spectrometry. It is most readily accomplished by using some form of pulse-counting detector in which ions are allowed to strike a target surface (conversion dynode) where each ion releases a pulse of low energy secondary electrons. The secondary electrons undergo further amplification in an electron multiplier or scintillator type of ion detector which is specially designed to detect single ions. Ion-to-electron conversion, amplification of the secondary electrons, efficiency of ion detection by pulse counting and dead-time corrections to observed random counting rates are all statistical processes which must be understood so that observed data can be corrected properly to obtain precise and accurate measurements. These processes are reviewed, along with some of the basic properties of ion-induced secondary electron emission from an amorphous Al2O3thin film target. Ion detection in the ion microprobe is interpreted in light of these basic considerations, and several mass spectra are given for electron multiplier dynode surfaces.
Fluorescence Analysis Using an Si (Li) X-Ray Energy Analysis
System With Low-Power X-Ray Tubes and Radioisotopes
Authors: Dyer G. R. , Gedcke D. A. , Harris T. R.
Published: March 2019

X-ray fluorescence spectroscopy has been in use since the early days of the twentieth century, when Moseley confirmed the order of the chemical periodic table. However, fluorescence spectroscopy until recently has depended on diffraction methods to obtain sufficient resolution. Intrinsic resolution of ionization chambers, scintillation detectors, and proportional counters is inadequate for discrimination o f lines due to adjacent elements of low atomic number. The advent o f solid-state detectors, especially those using lithium-compensated silicon and low-noise electronics, has recently brought intrinsic energy resolution to the point where lines from adjacent elements as light as carbon and nitrogen can be resolved in theory; and detection of K radiation from elements as light as sodium is practical. Thus the solution to the long-standing problem of an adequate detector is at hand, and energy-dispersive spectrometers are now feasible.
A Strategy Foe Rapid Aid Accurate (p.p.m.) Measurement of Lattice Parameters of Single Crystals by Bond's Method
Authors: Barns R. L.
Published: March 2019

All published accounts of the use of Bond's method for lattice parameter measurements have used step-scanning (at equal angle increments) of the diffraction peaks, followed by graphical or computer analysis of the data to locate the peak positions. It has been found that the peaks angles can be determined with little loss in accuracy or precision by manually setting the crystal angle to give a counting rate (observed on a rate-meter) equal to l/2 the peak rate and defining- the peak angle as the average of the angles on the two sides of the peak. Because of the asymmetry of the spectral line, defining the peak in this manner results in a shift of the peak angle from that determined by the mid-chord peak method. This shift can be compensated by determining an effective value of the wavelength based on a silicon standard. Using the method described, a lattice parameter measurement, including mounting and orienting the sample, taking the data and computing the result using a time-sharing computer terminal, can be made in less than 20 mins.
X-Ray Spectral Distributions from Thick Tungsten Targets in the Energy Range 12 To 300 Kv
Authors: Storm Ellery , Israel Harvey I. , Lier Douglas W.
Published: March 2019

Bremsstrahlung emission from four x-ray tubes operating at 12 to 300 kV was measured. Spectral distributions are given in terms of absolute-photon and energy fluxes. Silicon and germanium semiconductors, sodium iodide scintillators, and a xenon proportional counter were used to measure the spectra. Detector distortions were corrected by assuming an undistorted spectrum, distorting the spectrum with a Monte Carlo computer program, and comparing the results with measurement. The assumed undistorted spectrum was revised until the Monte Carlo calculation gave satisfactory agreement with spectral measurements from all four types of detectors. The effects on the spectra of varying the tube potential, tube current, target aperture, and detector aperture were investigated. Corrections for the intervening material and the solid angle subtended by the detector were applied to obtain the absolute-photon and energy flux from the target. Total fluxes in the L lines, K lines, and continuum are given.
X-ray-production efficiencies varied from 0.026% at 12 kV to 1% at 300 kV. The constant of proportionality varied in the range (0.23 to 0.73) x 10-6 kV-1.
Cross Linking of Collagen by Hydrophobe Bonds
Authors: Shaw Edwin H.
Published: March 2019

Previous work on modification of the collagen lattice, presented at these meetings, has served to confirm the Ramachandran proposal for the structure of this important protein, together with information on the lengths and tensile strengths of these bonds, including hydrogen bonds, hydrophobe bonds, and Vander Waals attractions. Rat tail tendons were suspended in 2 M aqueous solutions of dimethylsulfoxide, acetone, trimethylamineoxide and 1,4-cyclohexanedione, all of which showed evidence of ligation by expansion of the collagen lattice and refinement of the 100 spot in the x-ray diffraction pattern run by rotation on the collagen fiber axis. In the case of trimethylamineoxide and cyclohexanedione, oriented crystallization also occurred, with the long direction of the molecule in the plane perpendicular to the fiber axis of collagen. With the monofunctional ligands, the -C=0 group forms a hydrogen bond to the N-H group in the Ramachandran standard revised model, leaving the methyl groups to form the hydrophobe bond.
Detection and Spectroscopy of Long Wavelength X-Rays
Authors: Baun William L.
Published: March 2019

Instrumentation for spectrometry in the long wavelength X-ray region has been improved significantly in the last several years. In the area of excitation of soft X-rays, many changes have taken place. Secondary excitation source windows have been made much thinner and high power windowless and ultra thin windowed continuously pumped X-ray tubes have been developed. One source has been described which allows a choice of either primary or secondary excitation. Cold cathode techniques have been developed in which pressure control is achieved using an automatic pressure controller. Primary electron excitation has been revived and has become very important mainly due to the popularity of electron microbeam probe analysis. In the area of spectral dispersion, many improvements and innovations have been seen, recently in both grating and crystal spectrometers. Organic single crystals have been grown having 2d spacings up to about 100Ǻ and soap films have been fabricated with 2d spacing as large as 165Ǻ, allowing crystal spectrometers to be used to about 160Ǻ.
On-Stream Analysis of Liquid Samples Containing Elements of High and Low Atomic Number by X-Ray Fluorescence With Air and Vacuum Spectrograph
Authors: Chan Frank L .
Published: March 2019

Recently on-stream analysis by various methods and instruments has been greatly and rightfully emphasized. This is particularly true in such research as air and stream pollutions, desalting of ocean water and ore processing.

Among the various methods, instruments, and procedures adopted, the X-ray fluorescence method is perhaps the best among them. This is because the x-ray fluorescence method neither consumes nor destroys the samples taken for analysis. It also has the merits of simplicity and specificity. However, on-stream analysis of liquid samples containing elements having an atomic number below 20 by the X-ray fluorescence method is not an easy task particularly when vacuum spectrograph is being used.

In this study liquid cells of different dimensions for the on-stream analysis operated in air, helium and in vacuum have been successfully constructed. The cells have been tested for several months.
Chemical Bonding and Valence State—Nonmetals
Authors: Fischer David W.
Published: March 2019

The LIII x-ray emission bands from some 3d transition metal oxides and the K emission bands from some second and third period metal oxides and nitrides are shown and discussed in relation to the energy band structure of these compounds. It is demonstrated that the LIII emission bands can be grossly distorted by excitation conditions. Many of the compound spectra show strong evidence of a crossover transition which originates in the anion and terminates in the metal ion. For the 3d compounds this crossover transition appears to be related to the elsctrical and magnetic properties. In oxides of some second and third period elements it appears that the crossover transitions are responsible for the entire K band spectrum.
Crystal Imperfections and Magnetic Domain Walls in Thick Czochralski-Grown Nickel Single Crystals
Authors: Kuriyama Masao , Boettinger William J. , Burdette Harold E.
Published: March 2019

To study the relationship between crystal growth conditions and resultant crystalline perfection, large nickel single crystals more than 12 cm long and 2 to 3 cm in diameter have been grown from the melt by the Czochralski method. Unlike semiconducting materials, one cannot easily thin metal crystals, without straining them, for the purpose of applying ordinary Lang topography with μL∼l where kinematical scattering in imperfect crystals is a good approximation. This situation with metal crystals necessitates the use of dynamical diffraction effects in imperfect crystals to permit sample crystals to be thick enough to demonstrate their imperfections as in the bulk.
Study of the Precision of X-ray Stress Analysis
Authors: James M. R. , Cohen J. B.
Published: March 2019

Software is described for complete computer control of residual stress measurements. One program (that incorporates either the two tilt method, the sins| procedure, or the Cohen-Marion technique) has been developed for use with either a normal detector or a position sensitive detector. The operator inputs the desired error in stress and various instrumental parameters that determine systematic errors. The counting strategy to obtain the total error is then determined by the software.

Employing this automated system, an investigation of a parabolic fit to the top of a diffraction profile indicates that a three point fit is satisfactory only for sharp profiles.
The Effect of Temperature and Load Cycling on the Relaxation of Residual Stresses
Authors: Potter J. M. , Millard R. A.
Published: March 2019

The Fastress automatic residual stress measurement system was used to measure residual stress in unnotched shot peened 7075-T6 aluminum alloy specimens for a study of the effect of load and thermal exposure on residual stresses. Cyclic loads at zero and high mean stress conditions at stress levels in excess of those used in aircraft structures gave no apparent change in residual stress. Thermal exposure above 200°F resulted in significant changes in residual stress; at 225°F, 30 to 50 hours were required to cause the residual stress to reduce to onehalf the original value and less than 15 hours at 250°F was sufficient to cause a 50Z reduction. The data indicate that the cyclic load history that may be expected in aircraft structures is not sufficient to cause residual stress relaxation in areas remote from fasteners and other stress concentrations but that thermal exposure can cause significant relaxation.
Concentration of U and Np from Pu and Pu Alloys for Determination by X-ray Fluorescence
Authors: Hansel J. M. , Martell C. J. , Nelson G. B. , Hakkila E. A.
Published: March 2019

Methods are presented for the determination of uranium, or uranium and neptunium, in plutonium metal and plutonium alloys. Anion exchange or a combination of anion exchange - solvent extraction is used to concentrate the elements for x-ray fluorescence analysis, depending upon the impurities present and the elements to be determined. The precision for determining between 3 and 250 μg of uranium or neptunium ranges “between 30 and 2%.
Measurement of “Chemical Shift” by an Automated Commercial X-ray Fluorescence Spectrometer
Authors: Dowell L. G. , Bennet J. M. , Passoja D. E.
Published: March 2019

The measurement of “chemical shift,” that is, the change in energy of an element's x-ray emission lines with the state of its chemical combination, has been carried out for some years. Of the three major aspects of the technique, two have received major attention. Nagel (1) has an excellent treatise on the interpretation of valence band x-ray spectra, while such workers as Fischer (2) and Koffman and Moll (3) have attempted to correlate the data with structure. The third area, convenient data collection, has not been so well investigated. Much, but not all, of the effort has been toward direct electron excitation with its attendant problems of sample damage due to high vacuum and electron bombardment effects.
X-ray Intensities from Copper-Target Diffraction Tubes
Authors: Short M. A.
Published: March 2019

The relative intensities of the Kα characteristic radiation obtained from copper-target X-ray diffraction tubes have been calculated for a range of tube accelerating voltages and take-off angles. The calculations employ an over-voltage function, and absorption and atomic number corrections similar to those used in electron microprobe analysis. They apply only to constant potential X-ray generators. Measurements of actual intensities obtained on a Picker diffractometer using a sodium chloride monochromator gave relative intensities in close agreement with those calculated. The calculations and measurements show that there is an optimum tube voltage, with respect to intensity, for each take-off angle. This voltage increases with increasing take-off angle. The application of these results to the consideration of the relative intensities obtainable from broad, standard and fine focus copper-target X-ray diffraction tubes is discussed.
Accuracy in Angle and Intensity Measurements in X-Ray Powder Diffraction
Authors: Snyder Robert L.
Published: March 2019

The advent of computer automation and profile fitting techniques in powder diffraction., along with a general solution to the problem of preferred orientation, has opened a series of new horizons for this method. The new levels of accuracy attainable have brought us to the threshold of routine reliable qualitative phase identification, high precision quantitative analysis and the ability to perform crystal structure analysis on some of the most important technological materials. It has been primarily the question of accuracy which has held up these developments until now.
The JCPDS Data Base - Present and future
Authors: Wong-Ng Winnie , Holomany Mark , Frank McClune W. , Hubbard Camden R.
Published: March 2019

The Powder Diffraction File (PDF), published by the JCPDS-International Centre for Diffraction Data, is one of the most widely used scientific data bases. It currently consists of about 40,000 x-ray diffraction patterns, organized into 32 sets and 5 subfiles: metals and alloys, minerals, common phases, forensic patterns, and those from the National Bureau of Standards (NBS), New patterns are being added to the PDF at a rate of 2,000 patterns per year. The sources of these patterns are the literature, private contributions, grants in-aid projects, and the JCPDS Associateship at the NBS.
X-Ray Diffraction Intensity of Oxife Soild Soultions: Application to Qualitative and Quantitative Phase Analysis
Authors: Gehringer Ronald C. , McCarthy Gregory J. , Garvey R.G. , Smith Deane K.
Published: March 2019

Solid solutions are pervasive in minerals and in industrial inorganic materials. The analyst is often called upon to provide qualitative and quantitative X-ray phase analysis for specimens containing solid solutions when all that is available are Powder Diffraction File (PDF) data or commercial standards for the end members. In an earlier paper (1) we presented several examples of substantial errors in accuracy of quantitative analysis that can arise when the crystallinity and composition of the analyte standard do not match those of the analyte in the sample of interest. We recommended that to obtain more accurate quantitative analyses, one should determine the analyte composition (e.g., from XRF on grains seen in a SEM or from comparison of cell parameters with those of the end members) and synthesize an analyte standard with this composition and with a crystallinity approximating that of the analyte (e.g., as determined from peak breadth or α1/ α2 splitting).
Quantitative Analysis of Platelike Pigments by X-Ray Diffraction
Authors: Kamarchik P. , Ratliff J.
Published: March 2019

X-ray diffraction has been shown to provide an accurate qualitative and quantitative determination of the pigment composition of paint films. This analysis, however, is frequently complicated by the presence of pigments with plate-like crystallites which show a marked tendency to orient in preferred directions in drying paint films. The variability in the degree of orientation causes line intensity variations not attributable to pigment concentration.

A technique based on a summation of the intensities of many lines has been used to correct for the effects of preferred orientation in the analysis of retained austenite in certain steels. This method is shown to be applicable to the quantitative analysis of mica in paint films.
The Use of Multi-scan Diffraction in Phase Identification
Authors: Smith Gordon S. , Nichols M. C.
Published: March 2019

Phase identification by X-ray diffraction techniques in a complex mixture would be greatly simplified if the component phases could be physically separated. As opposed to current computer search-match algorithms for phase identification, which presuppose a single diffraction scan on a carefully prepared sample, we propose multi-scan data-taking on a not-so-carefully prepared sample so as to exploit certain aberrations in the diffracted intensities. The result can effectively be a physical separation by diffraction. Examples include exploitation of samples having a preferentially oriented component as well as samples with components having differing crystallite sizes. The techniques can involve diffractometer as well as film techniques.
On the X-Ray Diffraction Method of Measurement of Triaxial Stresses with Particular Reference to the Angle 2θo
Authors: Torbaty S. , Sprauel J.M. , Maeder G. , Markho P.H.
Published: March 2019

Certain machining processes (e.g. turning, grinding, …) lead to a splitting up and an opening out of the curve of 2θ ϕ ψ = f (sin2ψ). In order to determine the complete stress tensor, it is necessary in this case to use the Dölle-Cohen method but this requires the knowledge of the diffraction angle 2θo for the unstressed material. Such a material, however, is extremely difficult to obtain in practice and the method usually employed uses annealed powder for this measurement. In our study, we show that it is nevertheless possible to determine the angle 2θo on a specimen for which the curve of 2θ ϕ ψ = f (sin2ψ)
does not open out. Applying the Dölle-Cohen method to turning of a medium carbon steel, we have been able to bring to the fore: (i) the presence of an opening out of the curve 2θ ϕ ψ = f (sin2ψ), for measurements made in the direction of lay, which is attributed to a shear stress σ23, and (ii) shear stress σ12 which causes a rotation of the stress distribution diagram σϕ = f(ϕ) in the plane of the specimen.
A Comparison of the XRF11 and EXACT Fundamental Parameters Programs when Using Filtered Direct and Secondary Target Excitation in EDXRF
Authors: Vane Ronald A.
Published: March 2019

The XRF11 program by John Criss and the EXACT program are two commercially available fundamental parameters programs for energy dispersive x-ray fluorescence spectrometry (EDXRF). These programs are both based on the same underlying equations but use different approaches to the calculations. The EXACT program assumes monochromatic excitation, and the XEF11 program models polychromatic excitation sources. There are also great differences in how the two programs approach the iterations in the calculations and in how the data from standards are used in the two programs for calibration.

To produce the monochromatic excitation neeiled by the EXACT program, secondary targets have been the preferred method. But it is also possible to approximate monochromatic excitation by using filtered direct excitation. The purpose of this study is to compare the data obtained from both secondary targets and direct filtered excitation as processed through both XRF11 and EXACT.
A Correction Method for Absorption in the Analysis of Aerosols by EDX Spectrometry
Authors: de Jesus A.S.M. , van der Bank D.J. , Wesolinski E.S.
Published: March 2019

Low-energy x-rays can undergo considerable absorption in the sample material when EDX spectrometry is used in multi-element analysis of aerosol-loaded filters. An expression which corrects for the effects of absorption, based on counting aerosol filters and standards on both sides, is derived. The method is experimental verified by using the absorption of the 60 keV gamraa-ray of 241Am in aluminium and also by comparison with PIXE results for environmental filters.
Measurement of Composition and Thickness for Single Layer Coating with Energy Dispersive XRF Analysis
Authors: Shen Robert , Sandborg Alan
Published: March 2019

Methods for rapid and accurate analysis of coating composition and thickness are of major importance for the semiconductor industry. Typical coating problems are Al, Au or Pt coatings on metal and Cr/Ni alloy or SiO2/P2O5 glass on Si wafers. Due to the nature of the coatings ana tne variety of elements, a software package, COAT95 has been developed to cover the following three possible situations:

1. Single element coating for thickness only.

2. Compound, elements A and B, coating on substrate element S, for composition and thickness.

3. Compound, elements A and S, coating on substrate element S , for composition and thickness.

The main goal of the COAT95 software is to have all possible models for the single layer coating problems of the semiconductor industry.
Simultaneous Determination of 36 Elements by X-Ray Fluorescence Spectrometry as a Prospecting Tool
Authors: Feather Clive E. , Baumgartner Fritz C.
Published: March 2019

In regional reconnaisance geochemical prospecting, it is desirable to determine as many elements as possible, in order to provide a comprehensive cover for the detection of most types of ore mineralization. Multi-element simultaneous instruments are ideally suited to this task, but the maximum number of wavelength dispersive channels (monochromators) which may be fitted to any one of the commercially available X-ray spectrometers is approximately thirty. Because some of these channels are required for the measurement of background, the practical limit for spectral lines is about twenty-five. Additional elements may be determined by inclusion of a scanning channel, but its sequential operation increases the analysis time per sample.
Experimental XRF Calculation Method with Correction for a Polydisperse Material Particle Size
Authors: Zagorodny V. V. , Karmanov V. I.
Published: March 2019

A new experimental calculation method for polydisperse (i.e. heterogeneous) multicomponent material analysis has been developed using the dependence of element fluorescence intensity on the particle size and its distribution in the specimen. It is shown that correction of the influence of matrix particle size is possible using this experimental calculation method. For its application, the information on particle size distribution for each of the components is sufficient. Sample preparation includes only the pelleting of specimens under standard conditions. The efficiency of the method proposed is demonstrated by the analysis of the multicomponent mixtures of welding materials.
The Use of Bragg Reflection on Single Crystals for the Production of Polarized Excitation Radiation in the EDXRF
Authors: Beckhoff Burkhard , Kanngießer Birgit , Scheer Jens , Swoboda Walter
Published: March 2019

A monochromatic and linear polarized X-ray beam obtained by a Bragg reflection of a characteristic tube line under 90° on single crystals can be used as a EDXRF excitation source in a triaxial beam geometry in order to profit by the polarization effects reducing the scattering background in the fluorescence spectrum, A systematic selection procedure for 55 single crystals suitable for Bragg reflection was established. The selection procedure takes the following conditions and criteria into account. First of all the existence of appropriate lattice planes hkl fulfilling the Bragg reflection condition and having low Miller indices as well as a Bragg angle close to 45° ensures a high degree of polarization. Furthermore the integrated reflectivity Rifor these lattice planes should be as high as possible. For the validity of the formula for Riof an ideal mosaic crystal, the effects of primary and secondary extinction as well as of true absorption have to be considered. The critical limits of these parameters are calculated. The results of this systematic crystal selection procedure for the characteristic Kα lines of Cr, Cu, Mo and Ag tubes are presented.
L X-Ray Line Shape of Copper(II) Compounds and their Covalency
Authors: Kawai Jun , Nakajima Katsumi , Maeda Kuniko , Gohshi Yohichi
Published: March 2019

Profile changes of copper Lα (L3-V) and Lβ (L2-V) X-ray fluorescence spectra are interpreted. It is shown that the intensity of the high energy shoulder of the Cu L X-ray spectra has a relation to the intensity of the so-called ‘shake-up’ satellite in 2p X-ray photoelectron spectra; the high energy shoulder of the divalent copper La is weak for covalent compounds and strong for ionic compounds. It is also shown that the Lβ/Lα intensity ratio changes with the change of copper concentration of the analyte as well as the change of chemical state of the analyte.
Comparison of Elemental Sensitivities Induced by Radioisotope and Secondary Target Excitation for Simultaneous Multielement X-Ray Analysis
Authors: LaBrecque J. J.
Published: March 2019

The major advantage of secondary-target X-ray fluorescence analysis is the enchancement of sensitivity and detection limit of an element or small group of elements with similiar atomic numbers by selecting a target material which produces X-rays slightly higher than the absorption edges of the analysis of interest. Secondary target excitation systems are, however, being employed for simultaneous determinations of a large range of elements. Thus, it was decided to compare the application of a simple secondary target X-ray fluorescence system with excitation from a Cd-109 annular radioisotope source.

A simple secondary target X-ray fluorescence system was constructed and optimized which operates at less than 800 kilowatts. The “relative” elemental sensitivities of this system. and a radioisotope system with a Cd-109 annular source were compared by the analysis of the 1-2-3-multi-spectral standard from Chemplex which contains 1.23% of 53 elements. The characteristic X-rays were collected with the same Si(Li) detector and analyzed with the same Apple lie microprocessor with a Nucleus ADC/interface card. Finally, the secondary target system described herein with a molybdenum X-ray tube and zirconium or cadmium target produced similiar elemental sensitivities as a Cd-109 annular source of about 7.5 mCi and 5.0 mCi intensity respectively.
X-Ray Fluorescence Analysis of Oxide Magnetic Tape Using Thin Layer Fundamental Parameter Analysis
Authors: Kimura Ko , Wakamatsu Hideaki , Kitamura Takeshi , Maeda Ryozo , Fujiwara Kunthiro
Published: March 2019

In recent years, for the development of magnetic tape, it has become increasingly important that the elemental content be determined accurately and rapidly. In the past, the elemental content of magnetic tape was determined by calibration analysis using a wavelength dispersive X-ray fluorescence spectrometer(WDXRF). For calibration analysis many standard samples and large amount of sample were needed. Preparation of sample for calibration analysis, as well as for inductively coupled plasma emission spectral analysis(ICP) was difficult. On the other hand, for thin layer fundamental parameter analysis(we call TLFP) using a WDXRF, a few standard samples and l.pss sample are needed and preparation of the sample is easy. The superiority of TLFP analysis can be seen In comparison with calibration analysis and IOP analysis in Table 1. For this reason, this study has established a method for accurate and rapid determination of the elemental composition of oxide magnetic tape by TLFP analysis using a WDXRF.
Provenance of Kanjera Fossils by X-Ray Fluorescence and Ion Microprobe Analyses
Authors: Kinyua A. M. , Plummer T. , Shimizu N. , Melson W. , Potts R.
Published: March 2019

XRF and Ion mfcroprobe analyses of fossils of known and uncertain provenance from the Lower-Middle Pleistocene locality of Kanjera. Kenya, are reported. The goal of this study was to develop a nondestructive technique of provenancixig fossils, which could be applied to the Kanjera sample. The fossils of known provenance were collected in the excavations of the 1987 Smithsonian Expedition. Three fossils of uncertain provenance, two specimens of Theropithecus oswaldi and a hominid fossil, were analyzed as test cases.

Both qualitative and quantitative XRF analyses of Kanjera fossils were carried out. In the qualitative analysis, the elemental peak areas from each fossil's XRF spectrum were calculated and normalized to the peak area of the incoherently scattered radiation. Results of the analysis showed that fossils from the Lower-Middle Pleistocene Kanjera Beds, for the most part, had higher levels of yttrium (Y) and zirconium (Zr) than those of the younger Apoko (Ap) Bed. black cotton soil (BCS) and modem bones (MD). The relative concentrations of uranium (U) v strontium (Sri and thorium (Th) were diagnostic of the Kanjera Bed of origin. These findings were confirmed by quantitative XRF and ion microprobe analyses of a subsample of Kanjera fossils. The T. oswaldi and hominid fossils had trace element concentrations suggestive of K2 and BCS provenances, respectively. These findings provide a framework for the qualitative XRF provenancing of other surface collected fossils from the locality.
Two Easily-Overlooked Sources of Error in XRF Intensity Measurements
Authors: DeGroot Peter B.
Published: March 2019

Fundamental parameters methods of calculating elemental concentrations from x-ray fluorescence (XRF) data put stringent demands on the accuracy of XRF intensity measurement. Two significant but rather unobvious sources of intensity error are inaccurate deadtime correction in energy-dispersive x-ray fluorescence (EDX) systems and errors caused by certain combinations of sample thickness and geometry. A method of evaluating the accuracy of an EDX system's deadtime compensation is given. In our system, a nearly constant error was found over a wide range of average x-ray photon energy. Accurate deadtime correction was obtained by adding a mathematical correction to the partial compensation by the built-in system electronics. Problems related to sample thickness and geometry can result when the effective x-ray path length is longer than the geometrically possible path length (high energy analyte radiation and light element matrix). In such samples, a known sample thickness less than the geometry-limited thickness must be used for accurate intensities. A method for determining when this is necessary has been devised. A useful empirical correction for absorption by Mylar windows is also given.
Trace Analytical Capabilities of Total-Reflection X-ray Fluorescence Analysis
Authors: Michaelis W. , Knoth J. , Prange A. , Schwenke H.
Published: March 2019

The principle to utilize total reflection of the primary X-rays in fluorescence analysis is known since a lot of years. Nevertheless, analytical chemistry did not profit from the inherent advantages of the method for a long time. The main reason for this failure was the lack of instruments which were easy to use in practice. A few years ago, however, the development of a proper mechanical design and of adapted sample preparation techniques led to commercially available spectrometers which throughout fulfill the demands for routine applications. Since then the utilization of Total-Reflection X-Ray Fluorescence Analysis (TXRF) has increased rapidly. The scope of work is meanwhile widespread over environmental research and monitoring, mineralogy, mineral exploration, oceanography, biology, medicine and biochemistry. Accordingly, numerous matrices have been handled.
Excitation and Detection of High Energy Characteristic X-rays (20-90 KeV) Using a Novel Radiometric Technique*
Authors: LaBrecque J. J. , Rosales P. A.
Published: March 2019

Recently, we have developed a new radioisotope excited technique for x-ray fluorescence which employs “direct” beta particle excitation to produce characteristic x-rays for elemental analysis. We have also studied this technique with various other isotopes with different decay modes. But in all these previous works, we have only studied the x-ray energy region below the Bak lines (≤ 35 KeV), because of the poor efficiency of the Si(Li) semiconductor at higher energies.

In this work we have employed a planar Ge detector, which has about a 100% efficiency in the range of about 20 to 100 KeV. We have also compared this detector with a HgI2 detector, even though its resolution and efficiency is far less than the planar Ge detector.
Reflection Intensity Dependence on Surface and Wavelength from LiF and EDDT Analyzer Crystals
Authors: Toh K. , Ui T. , Asada E.
Published: March 2019

It has been recognized that more nearly perfect crystal surfaces have a low intensity of X-ray reflection as a result of extinction effects. Therefore, it has been common practice to abrade analyzer crystals used in X-ray fluorescence analysis so that they approximate so-called mosaic crystals.

While investigating the intensity of reflection from various ADP crystals about 10 years ago, one of the authors (A) and his colleague discovered that wavelength dependence of the intensity of reflection widely varied among crystals. in other words, crystals that had a high reflection intensity for short wavelengths displayed a low reflection intensity for long wavelengths, and crystals effective for long wavelengths were not effective for short wavelengths. Also, they discovered that this phenomenon was related to the perfect quality of the crystal surfaces. As-grown crystals were more effective for longer wavelengths than commercially available crystals into which a certain amount of imperfection presumably had been introduced.
A Fast, Versatile X-ray Fluorescence Method for Measuring Tin in Impregnated Wood
Authors: Drabæk Iver , Christensen Leif Højslet
Published: March 2019

The present paper describes an energy-dispersive x-ray fluorescence method for measuring tin in bis(tri-n-butyl)tin-oxide impregnated wood. The proposed method is of the backscatter/fundamental parameter type. Its versatility, precision, and accuracy is demonstrated by analyses of eleven samples of sapwood of Baltic Redwood. The results obtained are compared with those from neutron activation analysis.
Evaluating the Variability of Southwestern Ceramics with X-ray Fluorescence
Authors: Crown Patricia L. , Schwalbe L. A. , London J. R.
Published: March 2019

For the period after about 100 B.C., the Southwest has been broadly divided into four culturally distinct regions: the Anasazi, Mogollon, Hohokara, and prehistoric Yuman culture areas. Definition and identification of these areas has been based largely on extant material culture, particularly pottery and house-types. Pottery is especially important in archaeological investigations because it is unquestionably man-made and it is virtually indestructible in the dry Southwestern climate. The pottery produced by the inhabitants of the Southwest is also highly variable through time and across space, so that over 900 distinct ceramic types have been defined for Southwestern culture groups. And since potters tended to use materials available in the vicinity of their villages, materials analysis of plastic and nonplastic constituents of ceramics can aid in evaluating where pottery was made.
X-ray Diffraction Measurements via a UNIX+ Based System
Authors: Dunn D. S. , Marinis T. F.
Published: March 2019

We have automated a Seeman-Bohlin Guinier x-ray diffractometer by interfacing it to a minimally configured PDP 11/23 computer. The programs that run on the microcomputer to control the operation of the diffractometer are stored on a mainframe host running the UNIX+ operating system. A software interface allows a particular data acquisition program to be downloaded from the UNIX host and executed on the satellite processor. This same interface allows the collected data to be periodically off-loaded to the host for processing and storage.
The Structure and Lattice Parameters of Pentaerythritol Above and Below its Phase-Transition Temperature
Authors: Chandra Dhanesh , Fitzpatrick Joan J. , Jorgensen Gary
Published: March 2019

Pentaerythritol (C-(CH2OH)4) is a solid-state phase-change material which is a potential candidate for temporary storage of solar energy. This material is known to undergo an atomic structural rearrangement in the solid state above approximately 187°C, at which point a large amount of thermal energy is absorbed. Reversion of the structure to the low-temperature form releases this stored energy–thus pentaerythritol (P.E.) can be regarded as a temporary storage medium for heat.
Semiconductor Surface Characterization by Synchrotron X-ray Fluorescence Analysis
Authors: Iida Atsuo
Published: March 2019

Recently, external X-ray total reflection, or the grazing-incidence condition, is being widely used for the surface characterization in various research fields. Surface X-ray diffraction, or grazing-incidence diffraction/scattering, and total-reflection fluorescence XAFS (X-ray absorption fine structure) are typical, powerful techniques for surface characterization. X-ray fluorescence (XRF) analysis under the total-reflection condition has also been attracting much attention regarding analytical applications. Two types of XRF experiments have been carried out under the grazing-incidence condition. One is trace-element analysis of a dried solution sample or a semiconductor wafer; another is an analysis of the elemental concentration-profile in depth. Both experiments are closely related to each other, and are valuable and promising because of their non-destructive nature and the high precision of XRF analysis.
Trace Analysis Using EDS: Applications to Thin-Film and Heterogeneous Samples
Authors: Cross B. J. , Augenstine J. E.
Published: March 2019

Critical to “Trace Analysis” measurement are the concepts of detection and quantification. Detection means positively identifying a chemical component. The term Minimum Detection Limit (MDL), used here, follows that of Currie, and is the smallest concentration that yields a net count, above system background, which will be detected with a 95% probability (with only a 5% probability of false detection).
Grazing Incidence X-ray Fluorescence Analysis with Monochromatic Radiation
Authors: Schuster Manfred
Published: March 2019

X-ray fluorescence excited by a monochromatic collimated Mo-Kα beam at grazing incidence is measured as a function of the angle of incidence. Monochromatic excitation guarantees a well-defined penetration depth and enables a simple analytical description of the fluorescence intensity. This method is applied to a system of thin Cu and Ti metallization layers on a Si wafer and to As dopant concentration profiles in Si wafers.Thereby, the effect of annealing can be analyzed non-destructively.
Impurity Analysis on Si Wafer Using Monochro-Trex
Authors: Nishihagi Kazuo , Yamashita Noboru , Fujino Kobukatsu , Taniguchi Kazuo , Ikeda Shigero
Published: March 2019

Recently, semiconductors have been integrated and densified to much higher levels. Under this circumstance, control of surface impurity on the Si substrate has become more important. We have attempted to increase analytical sensitivity of the transition metals, which have the greatest influence on productivity.

For the last few years, x-ray fluorescence analysis, using total reflection as a non-destructive and speedy method, has been applied for surface impurity analysis of Si wafers. However, this method is insufficiently sensitive (to the level required for surface impurity analysis) and the lower detection limit is still 1011 to 1012 atoms/cm2 order because the continuous x-ray excitation causes lots of scattering which makes the background higher.
Chemical State Analysis by Soft X-ray Emission Spectra with Molecular-Orbital Calculations
Authors: Kawai Jun
Published: March 2019

This paper deals with soft X-ray spectra of compounds which have one or more spectator hole(s) in the valence orbitals. The aim is to give a simple picture of the complicated chemical effects and to describe implications of the chemical effects to know the chemical state from the complicated spectra of materials. The first example of the system which has a spectator hole in the valence orbital is the intensity modifications of the shake-off satellites (KM-→LM) in chlorine Kα spectra. The second example of the system which has spectator holes in the valence orbitals is the multiplet structure of Lα spectra of the transition-metal compounds. It is described that the chemical effects of these two systems are clearly interpreted by the avoided crossing [1] of the molecular orbitals, one of which has a localized hole. We also describe the systems which have no spectator holes. The interpretation of the X-ray spectra of these systems are easy by a molecular-orbital calculation at the ground state.