bluuebunny/crossref_metadata_2025 huggingface dataset:
An Automated Two-Crystal Spectrometer Employing Direct Angular' Positioning and Readout
Authors: Gregory T. K. , Best P. E.
Published: March 2019

A unique approach has been used in the construction of a vacuum-two-crystal spectrometer. The instrument uses digital shaft encoders directly coupled to the analysing crystal axes to give accurate absolute angular measurement over a 360° revolution of each crystal. Each axis is driven directly by a torque motor tachometer combination which allows precise speed and position control. The complete two-crystal carriage assembly rotates about the first crystal axis, thus permitting the x-ray tube to be fixed to the vacuum chamber. The carriage and detector rotations are driven through antibacklash gearing by smaller shaft encoder, torque motor, tachometer assemblies. Because the complete unit is housed within the vacuum chamber, there are no alignment changes on system pump-down. The spectrometer is part of a completely automated computer controlled system. The computer is used for data acquisition and analysis as well as for controlling the angular position of the analyzing crystals, detector, and carriage.
Rapid Quantitative Analysis by X-Ray Spectrometry
Authors: Giauque Robert D. , Jaklevic Joseph M.
Published: March 2019

An x-ray fluorescence analysis method applicable to the case of fluorescent spectra excited with monoenergetic x-rays has been developed. The technique employs a minimum number of calibration steps using single element thin film standards and depends upon theoretical cross sections and fluorescent yield data to interpolate from element to element. The samples are treated as thin films and corrections for absorption effects are easily determined- Enhancement effects, if not negligible, are minimized by sample dilution techniques or by selective excitation.
Proton-Induced X-Ray Emission Spectroscopy in Elemental Tsace Analysis
Authors: Johansson T.B. , Akselsson R. , Johansson S.A.E.
Published: March 2019

Using protons in the MeV range as excitation source and a high resolution Si(Li) detector, X-ray emission spectroscopy is shown to be capable of analysing many elements with Z > 15 simultaneously at the 10-12 g level, This work discusses a theoretical lower limit of detection at moderate proton energies and gives examples of possible applications: analysis of the elemental composition of air-borne particles as a function of particle size, oil slick identification, and analysis of water and blood serum.
Studies of X Rays Induced by Charged Particles
Authors: Duggan Jerome L. , William L. Beck  , Albrecht Larry , Munz Lee , Spaulding James D.
Published: March 2019

Characteristic x rays have been produced for a variety of samples by bombardment with protons in the energy range from 75 keV to 5 MeV. The experiments were performed with two accelerators. For the low-energy studies (less than 150 keV), a Cockcroft-Walton accelerator was used. The higher-energy studies were done with a 5 MV Van de Graaff. The x rays were measured with high-resolution Si(Li) and Ge(Li) detectors. Yields for the cross section of characteristic K- and L-shell ionizations were measured for titanium, vanadium, chromium, manganeses iron, cobalt, nickel, copper, silver, gold, bismuth, and uranium. The experimental cross-sections have been compared to the theoretical predictions of the Born approximation for an interaction of this type.

Trace element analysis by 4-MeV proton bombardment of samples in the 10-12 gm range has also been performed. Some comments with regard to analysis with these sensitivities will be made.
Proposed Flash X-Ray System for X-Ray Diffraction With Submicrosecond Exposure Time
Authors: Charbonnier Francis M.
Published: March 2019

X-ray diffraction studies have generally used low current, low voltage X-ray tubes (e.g., 50 mA, 50 kV). Consequently, exposure times ranging from seconds to hours have been required, limiting X-ray diffraction techniques to the study of essentially static situations. Using such an X-ray source with a very high speed detector, R. E. Green was able to reduce the exposure time for laue patterns of aluminum crystals to a minimum of 0.003 sec. Nanosecond exposure and pulse timing are required for certain events, e.g., X-ray diffraction study of material under shock compression. Q. Johnson achieved this by using a low voltage, very high current flash X-ray source (approximately 50kV, 50kA, 30 nsec). However, such a system is difficult to build and to synchronize, and is not commercially available.

Published X-ray yield data, particularly the recent work of J. W. Motz, indicate that both continuum and characteristic X-ray yields increase rapidly with electron energy, reaching a maximum for an electron energy ranging from 150 keV for titanium to 300 keV for copper to nearly 1 MeV for molybdenum.

To take advantage of this property, a 300 kVp, 30 nsec pulse, 5 nsec jitter flash X-ray system has been built which appears to meet the intensity and timing requirements for single pulse laue or Bragg diffraction studies. System design, calculated output and initial tests are represented.
On-Line Process Control Compositional Analysis of Aluminum Films Containing a Low Percentage of Copper
Authors: Glade G. H. , Matthews J. M. , Titcomb F. R.
Published: March 2019

Aluminum film conducting stripes are widely used for semiconductor device interconnection networks. The addition of a low percentage of copper significantly increases their life. Composition must be controlled to maintain product quality.

The paper discusses various methods used to analyze the copper composition in the aluminum films, and adaptation of one of these methods for process control application. A portable instrument designed for field use was adapted for use as an on-line instrument.
An Introduction to Low Energy X-Ray and Electron Analysis
Authors: Henke Burton L.
Published: March 2019

This is an introductory review of the physics and applications of low energy x-rays and electrons in the 10-1000 ev region. The basic interactions of these radiations within matter are discussed and typical de-excitation spectra, fluorescent x-ray and photoAuger electron, are presented. Specific examples of spectrographic methods and instruments for the low energy region are described as “based upon the use of long-spaced, Langmuir-Blodgett type of multilayers for ultrasoft x-ray analysis and the use of the hemispherical electrostatic analyzer for photo-Auger electron spectroscopy. Some examples of spectrographic signal, signal/background, and resolution are presented for applications to light element fluorescence, valence emission band, and photo-Auger electron analysis. The special aspects of the low energy x-ray analysis of high temperature plasmas and of x-ray astronomical sources in general are described.
Evaluation of Soft and Hard Scarttered X-Rays as an Internal Standard for Light Element Analysis
Authors: Taylor David L. , Andermann George
Published: March 2019

In the research described, the use of scattered x-rays has been successfully applied as an internal standard for the analysis of calcium in aqueous specimens containing a wide range of matrix components. In addition to the demonstration of the utility of scattered x-rays for light element analysis, some comments are offered on the fundamental aspects of this technique, since to date the method has not been explained thoroughly. The present research represents a continued effort to determine the fundamental importance of various parameters intrinsic to any collection of atoms undergoing scattering, such as the Rayleigh-Compton ratio, the scattering angle, the wave length utilized, and the presence or absence of discontinuities in the matrix absorption coefficient. It has been concluded that large values of the scattering angle coupled with short wavelength tend to yield improved internal compensation. The results also indicate that for light matrices the Compton component of the scattered continuum is of particular importance in achieving good internal standardization for matrix effects.
Soft X-Ray Valance State Effects in Conductors
Authors: Holliday J. E.
Published: March 2019

Investigation of the NiLIIIband at various excitation voltages and the use of Ni and Ti thin films in the path of the NiLII,IIIand TiLII,IIIradiation, has shown that with proper electrode geometry and using target voltages of about 4 kv the effect of self absorption on emission edge shift and band shape is negligible for these elements. However, the LII/LIIIintensity ratio of titanium is strongly effected by self absorption, but it is not effected for nickel and iron by self absorption.

A survey of several investigators’ soft x-ray band spectra from alloys and conducting compounds showed that the observed band changes were related to the electronegativity difference of the combining elements or the ionic character of the band. Peaks appearing on the low energy side of transition metal bands when combined with 2nd period elements appear to be a cross transition between the 2s or 2p band of the non-metal and inner level of the metal.
A Versatile Vacuum Scahhihg Double Crystal Spectrometer for Soft X-Ray Absorption Edge Studies
Authors: Bhalla A.S. , White E.W.
Published: March 2019

Studies of the fine structure of absorption edges in the soft x-ray region are becoming increasingly important as a tool for materials characterization. Examples of application includes determination of chemical state of elements, bonding and band structure studies. Intensity and resolving power of the x-ray spectrometer are important experimental considerations. As a rule adjustment of instrumental parameters, such as collimation, to give increased intensity adversely affect resolving power. Optimization of intensity and resolving power must therefore he achieved.

A newly designed double crystal spectrometer has been constructed for high-resolution absorption edge studies in the wavelength region of 5Ǻ to 70Ǻ.

The entire system is enclosed in a vacuum chamber ion pumped to the 10-7torr range. The second crystal motion is obtained by means of an ULTRADEX 360-sided polygon and sine arm that is automatically step-scanned. The spectrometer functions equally well in the (l, + l) and (l, - l) orientation and as a precise single crystal spectrometer.
System for Non-Dispersive Analysis of Lunar X-Rays from Apollo
Authors: Gorenstein P. , Gursky H. , Adler I. , Trombka J.
Published: March 2019

A non-dispersive X-ray detection system consisting of proporticnal counters plus filters is being prepared for the Command-Service Module of the Apollo spacecraft as part of a “geochemistry“ package. It will detect solar induced characteristic X-rays from the abundant elements on the lunar surface during the orbiting phases of the mission. The objective will be a compilation of a map of the lunar chemical composition and to detect regional differences. The system and its theoretical performance are described.
Electron Spectroscopy for Studying Chemical Bonding
Authors: Ragnar Nordberg
Published: March 2019

The results reviewed in this article were obtained by means of the ESCA technique at the Institute of Physics, University of Uppsala, Uppsala, Sweden and at the Department of Physics, Vanderbilt University, Nashville, Tennessee, USA.

The ESCA technique is basically the study of induced emission of photo and Auger electrons from a sample irradiated with x-rays. If the incident radiation is monochromatic (e.g. an x-ray emission line) the spectrum of these electrons gives precise information about the energy states of the electrons in the sample. To extract this information, high resolution electron spectroscopy is necessary. Instruments for such spectroscopy have therefore been extensively developed during the last decade.
Correlation of Residual Stress Level and Fatigue Damage in B. C. C. Metals
Authors: Koves G
Published: March 2019

The development of materials with optimum fatigue characteristics hinges on a better understanding of the fatigue mechanism ( i .e ., fatigue crack nucleation and propagation) under specific loading conditions. A correlation was established between the residual macroscopic stress level--as measured by x-ray diffraction analysis, the fatigue damage in the form of slip-band formation and intensification, and the fatigue life at various applied stress levels of pure iron and low-carbon steel.

Residual stresses were measured by an automated diffractometer technique (Fe 211 Kα reflection, Cr radiation) and computer calculation of both macroscopic (line shift) and microscopic (line broadening) stresses . Surface fatigue damage was observed by optical microscopy.
Mass Absorption Coefficient Measurements Using Thin Films
Authors: Lublin P. , Cukor P. , Jaworowski R. J.
Published: March 2019

For quantitative electron probe analysis, the raw intensity ratios must be corrected to take into account deviations due to absorption, fluoresecnce and electron beam penetration. The major correction is usually the absorption correction, so that for best results, accurate mass absorption coefficients are required. Many tables of absorption coefficients are calculated by interpolation or extrapolation from available measured values, and therefore new measurements are required for increased reliability. The region which requires the most attention for present-day probe analysis is the 2 to 10 Å range.

Thin foils of the lighter metals are available for mass absorption coefficient measurements, but heavy metal foils, which must be extremely thin, are not obtainable, A method has been developed to prepare thin films of heavy metals on a suitable substrate by pyrolytic decomposition of metal organic compounds.
X-Ray Absroption Table for the 2-to-200 Å Region
Authors: B. L, Henke and  , R. L. Elgin
Published: March 2019

Physical and chemical analysis, X-ray astronomy and high temperature plasma diagnostics which utilize the ultrasoft X-radiations hare made evident a strong need for filling the gap in measured absorption coefficient data for the radiations between the conventional X-rays and the extreme ultraviolet. More than one hundred new coefficients have been measured in this laboratory on the gas state, atomic or molecular, containing He, C, N, 0, F, Ne, S, Cl, Ar, Kr and Xe using eleven fluorescent, characteristic wavelengths Al-Kα (8.34 A) through Be-K (113.8 A). The radiations were isolated by Bragg reflection from multilayer analyzers of the Langmuir-Blodgett type and by pulse height discriminating proportional counter intensity measurements.
Phase Identification by X-Ray Powder Diffraction Evaluation of Various Techniques
Authors: Hanawalt J. D.
Published: March 2019

Three powder mixtures, each composed of four or more phases, were submitted for phase identification by x-ray diffraction. Laboratory technicians supplied tables of “d” values and of relative intensities as obtained separately and independently by use of the diffractometer, the Debye camera and the Guinier camera. These tables of diffraction data were “solved” by utilization of the Joint Committee search manuals and reference to the Joint Committee Powder Diffraction File (P.D.F.). The same tables of data were then submitted to the 2dTS:Diffraction Data Tele∼Search for a computer printout of results. Experimental data are also presented which provide a quantitative comparison of the accuracy of measurement of “d” values and of the resolution of Debye cameras vs Guinier cameras, since this information is necessary for efficient search procedures whether by manual or computer methods.
Computer searching of the Jcpds powder Diffraction File
Authors: Dismore Faden F.
Published: March 2019

Jackson Laboratory is using computer searching of the powder diffraction file on an “in-house” IBM 365/65 computer for about 1000 searches per year. This paper will discuss our experiences with the search program.

A Philips Automatic Powder Diffractometer (APD), modified to communicate with an XDS Sigma 5 computer collects the data. A program in the Sigma 5 provides both hard copy output and a computer deck of punched cards for input to the JCPDS search program.

The JCPDS search program is indispensable for our large volume of samples . The majority of these samples are corrosion products which generally have “broad peaks, and frequently, preferred orientation.
Direct Quantative Determination of Silica by X-ray Diffraction on Pvc Membrane Filters
Authors: Henslee W. W. , Guerra R. E.
Published: March 2019

Exposure of industrial workers to respirable crystalline silica is receiving considerable attention at present from industrial laboratories and regulatory agencies. Analytical methodology for rapid and accurate determinations of microgram quantities of silica is necessary. The X-ray diffraction method which has been recommended by NIOSH requires lengthy sample preparation.

An X-ray diffraction method has been developed for the quantitative analysis of α-quartz directly on polyvinyl chloride filters in the microgram range. The minimum detectable concentration of α-quartz is approximately 2μg/cm2. This represents a sensitivity comparable to that claimed using the Bumsted method. The necessity of ashing the filter and depositing the residue on silver membrane filters, as well as the addition of a standard, is avoided. This minimizes handling and alteration of the sample.
Internal Standard and Dilution Analyses Applied to the Kinetics of TiB Formation
Authors: Walther G. C. , Gould M R. W.
Published: March 2019

The reaction kinetics of forming TiB in a mixed powder compact were analyzed using internal standard and dilution methods. The dilution method was not successful due to insufficient dilution, while the internal standard method was satisfactory to confirm that diffusion is the rate controlling mechanism. Difficulties analyzing metal powders and diffusional film products in mixed powders are discussed.
Stress Measurements in Thin Films Deposited on Single Crystal Substrates Through X-ray Topography Techniques
Authors: Hearn E. W.
Published: March 2019

The application of x-ray topographic techniques to the measurement of stress in thin, films is discussed. Quantitative measurements of stresses in thin films deposited on semiconductor substrates, such as silicon, are also discussed. Double crystal and single crystal techniques are used for such measurements. Both techniques are applied to the measurements of stress in silicon oxide, silicon nitride and polycrystalline silicon films on silicon. The doubly crystal technique is useful for measurements of stresses as low as 109 dynes/cm2 in films only 1000A thick. The single crystal technique is less sensitive by one order of magnitude. The advantage of the single crystal technique is its simplicity and speed. It is useful for large scale measurements as encountered in the manufacture of silicon integrated circuit.
The Meed for Experimentally Determined X-ray Elastic Constants
Authors: Marion R. H. , Cohen J. B.
Published: March 2019

In order to convert residual strains measured by x-ray diffraction techniques into residual stresses, appropriate x-ray elastic constants have to be measured. Since these x-ray elastic constants may depend on the metallurgical state, deformation, and entire specimen history, errors in stress values may result if the constants are not measured for representative material states. In the present work, it is shown that in same cases these errors may be large.
Powder-Pattern: A System of Programs for Processing and Interpreting Powder Diffraction Data
Authors: Pyrros Nikos P. , Hubbard Camden R.
Published: March 2019

The production of standard x-ray diffraction patterns at NBS imposes special requirements in the data processing of powder patterns. The patterns should be complete and have an overall accuracy of better than 0.01 degree two theta. To ensure completeness all the observable peaks should be indexed. To make certain that the sample is a pure phase, weak peaks have to be identified as well.

The indexing of all the peaks implies that the cell constants must be known and there should be a good agreement between all the calculated and observed peak positions. In practice this is achieved by a least-squares refinement of the unit cell parameters. This serves as a test of the assumed unit cell and also as an interpretation of the observed peaks. Finally, an attempt is made to identify the space group. This step also requires the identification of weak peaks. The agreement of a known space group with the observed reflections further confirms the purity of the sample.
Computer-Aided Qualitative X-Ray Powder Diffraction Phase Analysis
Authors: Goehner Raymond P. , Garbauskas Mary F.
Published: March 2019

This paper describes a set of interactive computer programs written in FORTRAN IV and implemented on a POP 11/34 equipped with RLO-2 ten Mbyte discs and an RSX-11M operating system to assist in x-ray diffraction phase analysis. The packing of the data base will be described along with the various interactive programs that access it. The search/match package is designed more as a set of aids for the diffractionist rather than as a single totally automated search/match program, the procedure adapted by many of the xray diffraction (XRD) equipment manufacturers. The approach taken allows the analyst to direct the analysis procedure by utilizing different search/match programs or specifying various options within a given program.
The Dramatic Effect of Crystallite Size on X-Ray Intensities
Authors: Cline James P. , Snyder Robert L.
Published: March 2019

Preferred orientation has long been considered the primary source of systematic error involved in quantitative analysis by X-ray powder diffraction. Techniques of spherical agglomeration have been shown to eliminate preferred orientation provided that the agglomerate size is made sufficiently larger than the particle size. These techniques invariably employ the surface energy minimization of a liquid phase dispersed within a second fluid to create the spherical form desired. Spray drying has been the only method to date which has been successfully used to prepare spherical agglomerates suitable for X-ray diffraction. This study was undertaken to investigate possible deleterious effects of spray drying as a diffraction sample preparation technique.
Preparation and Certification of Standard Reference Materials to be Used in the Determination of Retained Austenite in Steels
Authors: Hicho George E. , Eaton Earl E.
Published: March 2019

In the steel hardening process, steel is heated to a temperature where a face-centered-cubic solid phase called austenite is formed. After a stabilization period, the steel is quenched into a medium which transforms the austenite into a metastable, body-centered-tetragonal solid phase called martensite. On occasion the austenite is not entirely transformed into martensite and some austenite remains. This untransformed (retained) austenite is sometimes detrimental to the finished product, and often there are requirements as to the amount of retained austenite permitted In the finished product.

X-ray diffraction procedures (XRD) are normally used to determine the amount of retained austenite and this paper describes the preparation and characterization of the Standard Reference Materials used to calibrate x-ray diffraction units.
Profile Fitting for Quantitative Analysis in X-Ray Powder Diffraction
Authors: Schreiner Walter N. , Jenkins Ron
Published: March 2019

Quantitative phase analysis by powder diffractometry requires accurate measurement of the integrated intensities of the diffracted, lines. When lines are isolated and on simple backgrounds, count integration techniques work very well. However, when one or more lines overlap the line of interest, or a complex background is present, profile fitting techniques are required in order to eliminate interferences.

Profile fitting involves choosing a mathematical model to represent the expected profile shapes. Experience has shown that the profile shapes obtained with a parafocusing powder diffractometer are not easily described and many models have been tried with varying degrees of success. Generally the more free parameters allowed In the model the ‘setter the fits, although, aesthetically one would like to keep the number of free parameters to a minimum.
The Use of Mn-Kα X-Rays and a New Model of PSPC in Stress Analysis of Stainless Steel
Authors: Yoshioka Yasuo , Hasegawa Ken-ichi , Mochiki Koh-ichi
Published: March 2019

The authors previously reported stress measurement in stainless steel by the use of monochromatic Cr-Kβ X-rays and a position sensitive proportional counter. Results indicated that a stress value can be obtained with high precision on account of the subtraction of background and the elimination of αFe(211) peak by Cr-Kα X-rays. The major disadvantage of this method, however, is that the intensity of Kβ X-rays monochromatized is essentially weak and it is complicated to eliminate Kα X-rays for practical use.
Direct Determination of Stress in a Thin Film Deposited on a Single-Crystal Substrate from an X-Ray Topographic Image
Authors: Berry Wayne S.
Published: March 2019

X-ray topography is one of several methods used by the semiconductor industry to measure stress of thin films deposited on single crystal substrates. A procedure to determine stress values directly from the X-ray topographic image by measuring the separation of the Kα1-Kα2 X-ray peaks is reviewed. Although less sensitive than the single-crystal technique, it has been found applicable to monitor stress levels in films such as CVD silicon nitride on silicon wafers. This technique may also be used to quantify the plastic deformation of wafers that is induced by semiconductor processes.
Energy Resolution Measurements of Mercuric Iodide Detectors Using a Cooled Fet Preamplifier
Authors: Ames Lawrence , Drummond William , Iwanczyk Jan , Dabrowski Andrzej
Published: March 2019

The performance of a room temperature mercuric iodide X-ray detector was investigated as a function of detector bias, amplifier time constant, and detector temperature. A Mn Kα line of 200 eV FWHM was obtained by using low noise electronics developed for Si(Li) detectors, including a cooled input PET. Measurements of the detector's resolution at various X-ray energies result in a Fano factor of 0.20.
Multielement Analysis of Unweighed Biological and Geological Samples Using Backscatter and Fundamental Parameters
Authors: Nielson K.K. , Sanders R.W.
Published: March 2019

A new approach to fundamental parameter calculations has been devised which makes use of incoherent and coherent backscatter intensities from the excitation radiation. The backscatter results from all sample constituents, and thus provides information on total sample mass as well as on bulk sample composition. By appropriately using the scatter intensities in fundamental parameter matrix calculations, accurate analyses of “unknown“ samples can be obtained without prior knowledge of the sample matrix. The backscatter with fundamental parameter (BFP) method is especially advantageous for biological, geological and environmental samples because of their bulk quantities of carbon, oxygen, and other light elements which cannot be explicitly determined for traditional fundamental parameter calculations.
Application of XRF to Measure Strontium in Human Bone In Vivo
Authors: Wielopolski L. , Vartsky D. , Yasumura S. , Cohn S.H.
Published: March 2019

Strontium appears in the earth's crust at a concentration of about 400 ppm and in sea water about 8,1 ppm. Consequently, all living forms have evolved in the presence of this alkaline earth and have incorporated it in their tissues. The exact role of Sr in the human body remains ambiguous (1), even though Sr has been extensively studied with reference to the radiation hazard from 90Sr (2).

Metabolic behavior of Sr, in some aspects, is similar to that of Ca (3), but substantial dissimilarities between these two are also well recognized (1,4). It has been suggested that Sr stimulates the formation of bone matrix. At higher concentrations, however, it interferes with calcification mechanism of the bone matrix (5).
Theoretical Calculation of Background in X-Ray Spectrometry for the Determination of Some Heavy Trace Elements
Authors: Gruffat Jean-Jacques
Published: March 2019

The Kulenkampff-Kramers formula giving the spectral distribution of the continuum as a function of wavelength allows a correct calculation of background under the peak. It is only necessary to measure two backgrounds, one on each side of the peak, The true background under the peak is given by multiplying them by adequate coefficients and adding them up. This method has been applied to the determination of low amounts of Ce, La, Ba and Cs in geological samples.
Systematic Computation of Scattering Corrections with the Code Shape
Authors: Fernandez J.E. , Molinari V.G.
Published: March 2019

The recently developed code SHAPE allows the build-up of EDXRF spectra for collimated and monochromatic excitation. In this work the code is applied to investigate the Importance of the scattering corrections to the more intense XRF characteristic lines from low and medium Z elements. Results are given graphically for pure elements from Z=11 (Na) to Z=42 (Mo). Heavier element lines from a multi-component geological sample, where light matrix amplifies the influence of scattering, are studied.
Depth Profiling by Means of X-Ray Fluorescence Analysis
Authors: Ebel H. , Svagera R. , Rezai Afshar S.
Published: March 2019

Sherman described the excitation of characteristic radiations by primary x-rays and by secondary excitation. The derivation has been made assuming a homogeneous sample. Criss and Birks inverted the problem from the calculation of fluorescent countrates to the quantitative XFA by means of fundamental parameters. Theoretical and instrumental developments enabled a reduction of the sample area and led to small area XFA and imaging XFA sytems. Depth profiling by means of XFA is a further development. We continue the original concept of variable take-off angle technique for the determination of film thicknesses without reference samples and apply the variation of the incidence angle to depth profiling.
X-Ray Studies of Chromium Nitride (CrxNy) Thin Films Deposited by Reactive Magnetron Sputtering
Authors: Charbonnier M. , Romand M. , Roche A. , Terrat J.P.
Published: March 2019

Chromium nitride hard coatings have been prepared by a plasma process by varying nitrogen partial pressure. The crystallographic structure of these samples has been investigated by XRD and their chemical composition and stoichiometry by Low Energy Electron Induced x-ray Spectrometry (LEEIXS).
Instrumentation for Total Reflection Fluorescent X-Ray Spectrometry
Authors: Utaka Tadashi , Arai Tomoya
Published: March 2019

This article describes the instrumentation for a total reflection fluorescent x-ray spectrometer. The reflecting intensity and the angular divergence were studied with respect to various kinds of monochromators. Using silicon wafers, the angular divergence effect of the incident beam, surface roughness influences and the smoothing of background x-ray intensity for the improvement of the lower limit of detection were investigated.
A High Resolution Portable XRF HgI2 Spectrometer for Field Screening of Hazardous Metal Wastes
Authors: Bernick M. , Berry P. F. , Voots G. R. , Prince G. , Ashe J. B. , Patel J. , Gupta P.
Published: March 2019

The use of a field portable XRF analyzer incorporating a semiconductor, mercuric iodide, energy dispersive spectrometer is described with emphasis on the benefits of high resolution x-ray detection for rapid screening of hazardous metallic wastes. Results are presented of “in-situ” and “prepared sample” soil measurement for different sites to show the potential of Fundamental Parameter analysis to obtain acceptable quality data with minimum calibration effort, obviating the need for site-specific standards.
A New Instrument for the Energy Dispersive X-Ray Fluorescence Analysis of Objects of Art and Archaeology
Authors: Schreiner Manfred , Mantler Michael , Weber Franz , Ebner Richard , Mairinger Franz
Published: March 2019

Objects of art and archaeology are relicts of the past, and art historians, archaeologists and conservators are constantly concerned with the questions of where, when or by whom such artifacts were made. Usually stylistic considerations can provide answers to these questions, but as styles were sometimes copied at locations and times quite different from those for which they were most characteristic, material analysis is often essential when one is attempting to infer how and of what materials an object was made. The use of several compounds e.g. as pigments in paintings, or the deliberate alloying of Cu with Sn, As, Sb and Pb, has varied greatly from region to region and from time to time and can be used to infer the geographic origin of an object or at least the origin of the materials, out of which it was made.
X-Ray Microprobe Studies of Hungarian Background and Urban Aerosols
Authors: Török Sz. , Sándor Sz. , Xhoffer C. , Van Grieken R. , Jones K.W. , Sutton S.R. , Rivers R.L.
Published: March 2019

In order to determine the polluting atmospheric sources in urban and background areas source apportionment of the air particulate matter is necessary. Hitherto these studies were mostly based on bulk composition measurements of the aerosol. Source profiles, i.e. the concentrations of several elements for air particulate matter originating from one source, can be deduced from the receptor data using a number of multivariate techniques among which the chemical mass balance. The application is limited by the large number of observations that must be made for each of the variables. Often an elaborated sample preparation is necessary for fractionating the sample into several sub samples, according to the density, particle diameter or other relevant properties . Often this may results in poorly resolved source profiles.
Using a Priori Information in Energy-Dispersive X-Ray Fluorescence Analysis of Complex Samples
Authors: Kondurov I. A. , Sushkov P. A. , Tjukavina T. M. , Shulyak G. I.
Published: March 2019

In multielement EDXRF analysis of very complex unknowns, some problems in data evaluation may be simplified if one can take into account a priori information on the properties of the incident and detected radiations, and also available data on the matrix of the sample. The number of variables can be drastically shortened in the LSM procedures in this case. One of the best examples of complex unknowns is the determination of the rare earth element content of ores, and most recently in samples of high temperature superconductors (HiTc).
An Evaluation of Correction Algorithms, Using Theoretically Calculated Intensities
Authors: Vrebos Bruno A. R. , Helsen J. A.
Published: March 2019

Several correction algorithms (Lachance & Traill (L-T), Rasberry & Heinrich (R-H), Lachance & Claisse (L-C) and Claisse & Quintin (C-Q) have been inter compared. All these algorithms assume that the effects of the matrixelements can be added in a linear way. Tertian, however, has shown that this is perfectly valid only when absorption is the only interelement effect to be taken into account. When enhancement is involved, corrections for crossed-effects are necessary. We have also evaluated the application of crossed-effect correction. Calculations were done, using theoretically calculated relative intensities. Influence coefficients were calculated by a regression method.
The Application of Linear Polarized X-rays After Bragg Reflection for X-ray Fluorescence Analysis
Authors: Wobrauschek Peter , Aiginger Hannes
Published: March 2019

Polarized x-rays are used to excite samples of any kind and shape to emit characteristic radiation. In the appropriate geometry, where source-sample-ED detector are in any orthogonal position to each other, the exciting poLarized x-rays will be practically not scattered from sample and substrate into the detector. This reduces the background considerably and hence improves the lower limits of detection. The production of intensive polarized x-rays is done by using a single crystal-where Bragg reflection occurs at an angle 2 θ = 90° instead of amorphous low Z scatterers. The result is a linear polarized and monochromatic beam. The use of curved crystals instead of plane single crystals further increases the intensity of the exciting radiation. The lower limits of detection attainable with the recently constructed compact polarizer device are in the sub ppm range or in absolute amounts around 150 pg for medium Z elements.
High Temperature X-ray Diffraction Studies of the Defluorination Reactions of Chukhrovite, Falphite and Ralstonite
Authors: Wilson Robert L. , Mu Jacob , Bradford James L.
Published: March 2019

Current commercial processes for the production of wet-process phosphoric acid involve the dissolution of phosphate rock and separation of insoluble solids by filtration. Calcium is removed by the addition of H2SO4, to precipitate CaSO4•2H2O. Other metallic impurities are removed by extraction or precipitation.

In a new process. Lower grade phosphate ore can be digested with recycled phosphoric acid. If the raw acid contains a fairly high concentration of Mg, it may be enriched in fluoride ion.
A Comparison of Detection Systems for Trace Phase Analysis
Authors: Robie Stephen B. , Scalzo Thomas R.
Published: March 2019

Since the introduction of semiconductor detectors with sufficient energy resolution to resolve K-alpha X-rays from the K-beta X-rays for first row transition metals, there have been several attempts (1,2) to replace traditional detector systems (scintillation detector/graphite monochromator or proportional counter/nickel filter) in X-ray diffraction with semiconductor detectors. The goal of these experiments was to increase the total system detection efficiency by combining the K-beta discrimination and X-ray detection into a single operation. These early attempts showed that the semiconductor detector based system was more efficient, however, the problem of large dead-time losses hampered development in this area.
Determination of the Crystal System of a Neodymium-Iron-Boron Alloy by X-ray Diffraction
Authors: Wims Andrew M. , Johnson Jack L.
Published: March 2019

The MAGNEQUENCH process for making high energy product (> 10 MG•Oe) permanent magnet alloys of Nd2Fe14B has been described. To advance further the commercial application of these alloys, a better understanding of the microstructure and crystallography is required.

The crystal system and unit cell parameters can be determined from the angular positions of the x-ray diffraction peaks, provided the data have been collected with a 2θ accuracy error of <0,02°. Computer based methods are available for handling the large number of calculations required. This paper describes the experimental problems encountered and solved during the determination of the cell parameters for this alloy.
Glancing Angle X-ray Absorption Spectroscopy
Authors: Greaves G. N.
Published: March 2019

The use of glancing angles of incidence enables X-ray Absorption Spectroscopy to be measured as a function of depth from the surface of a material into the bulk. As x-rays rather than photoelectrons are detected, a UHV environment is not required and instead surfaces and interfaces can be examined under realistic operational conditions. Whilst the reflected beam carries the fine structure of concentrated species in the imaginary part of the refractive index, this is obscured by the contribution from the real part for angles greater than ϕc, the critical angle for total external reflection. Measuring the x-ray fluorescence offers more flexibility, particularly for dilute systems. The use of synchrotron radiation in conjunction with a multi-element Solid State Detector enables impurity loadings down to a few 1019 cm-3 to be measured which for ion implants is equivalent to around half-monolayer coverage at the surface. This sensitivity makes it practical to examine impurities in semiconductors at realistic dopant levels.
Soft and Ultra-Soft X-ray Spectrometry Using Long-Wavelength Dispersive Devices
Authors: Charbonnier M. , Gaillard F. , Romand M. J. , Urch D. S.
Published: March 2019

X-ray emission spectrometry is of great practical interest because the method is rapid, non destructive and quantitative. However, the analysis of light elements which emit highly absorbed long wavelength radiations is always difficult. Although recent development of multilayered microstructures as dispersive devices has brought higher count rates for light elements, the improvement of performance in the relevant energy range depends, largely, on the improvement of the excitation. For this purpose, an electronic source providing a non-focused low energy electron beam constitutes a means of obtaining a very efficient excitation. As a result, we have used such an excitation to compare the performances of some layered synthetic microstructures (LSM) and conventional crystals for the detection of soft and ultra-soft xrays, to show up a few spectral interferences and to solve them by choosing the best dispersive device. Among the cases studied, we have shown how to carry out an accurate analysis of boron in borophosphosilicate glass (BPSG) samples. Finally a survey of the lower detection limits obtained for different elements using different dispersive devices was done.
X-ray Fluorescence Analysis of High-Density Brines Using a Compton Scattering Ratio Technique
Authors: Samuelson Michael L. , McCormell Stanley B.
Published: March 2019

High-density brines are used to control high pressure during oil and gas well operations. These dense brines (15 to 20 lb/gal) are solutions prepared from sale such as calcium chloride, calcium bromide, zinc bromide and/or combinations. During stages of completion, excessive losses of these expensive brines to the production zone can occur. Before the brine is reused in other oil and/or gas well operations, the brine may need to be reweighted. An analysis of the brine composition must be obtained to properly add the correct amount of salts.

Standard addition or internal standardization methods are commonly used in X-ray fluorescence (XRF) applications but negate one of the advantages of XRF-elimination of tedious sample preparation. Scattered X-ray intensity has been used successfully to correct matrix effects in XRF applications. A Compton scatter ratio method is very advantageous for samples having a low atomic number, for which the scattered intensity is high. This paper describes an XRF method for determining Ca, CI, and Zn in high-density brines as well as the matrix correction for Br using a scattered X-ray ratio technique.
Mass Absorption Corrected X-ray Diffraction Analysis of Entrained-Flow Reactor Coal Combustion Products
Authors: Collins Leo W. , Wertz David L.
Published: March 2019

The analysis of coal and the understanding of the combustion process is complex, due to the heterogeneous nature of the material and the myriad of high-temperature reactions inherent in this fossil fuel. The research presented below utilizes recently-developed x-ray diffraction methods to analyze the coal combustion products generated from a laboratory-scale entrained-flow reactor. The reactor was designed, constructed, and tested, as planned for the initial phase of a long-term project to evaluate the coals located in Mississippi. In this initial phase a well-characterized coal was used, supplied by The Pennsylvania State University. The proximate, ultimate, and sulfur analyses of the coal, PSOC 1368p, are outlined in the Appendix. X-ray diffraction techniques have been used In the past to characterize coals. An analysis of the mineral transformation during coal combustion has also been performed using x-ray diffraction instrumentation. The semi-quantitative results of the pyrite (FeS2) phase transformation at variable temperatures and the percent combustion of the coal, as determined by x-ray methods are reported below.
A Focusing System for X-ray Diffraction Studies of Materials Under High Pressure in the Diamond Cell
Authors: Wu Y. , Thompson A. C. , Underwood J. H. , Mao H. K. , Fei Y. W. , Hu J. Z. , Badding J. V. , Shu J. F.
Published: March 2019

Recent advances in techniques to generate static ultra-high pressure (>100 GPa) in the diamond anvil cell have significantly enhanced our understanding of the properties of solids under these extreme conditions. In order to characterize the structure of solids at these pressures, X-ray diffraction using synchrotron radiation has become an invaluable tool. Since the highest pressures are attained at the expense of sample volume (~ 100 μm3) , it is best to use the intense radiation available from a synchrotron to study the very small samples used in ultra-high pressure studies. Even with the intense x-ray beams currently available, it is still often desirable to focus the x-ray beam to increase the available flux. We have developed a focusing system which uses multilayer coated spherical mirrors. With this system, intense x-ray beams with sizes smaller than 10 μm by 10 μm can be achieved at a synchrotron radiation beamline. Previously, we used the focusing system for x-ray microprobe experiments.
The Thickness Measurements of Thin Bulk Film by X-ray Method
Authors: Hirose Y. , Takano N. , Nanayama Y. , Mura T.
Published: March 2019

There are many investigations about thin film. However, these are limited to the surface layer thin film on substrates. It Is very important to know the characteristics of the extremely thin film itself such as surface layer thin film.

In the present paper, the first part deals with the thickness measurements of the surface layer film and substrate by means of x-ray method, and then the measurement method of their stress - strain curves and the procedure of the measurement are described. The results obtained are discussed on the basis of their stress — strain curves.
Oxygen Concentration Determination in Silicon Single Crystals by Precision Lattice Parameter Measurement
Authors: Ohmori H. , Tomita M. , Tsuchiya N. , Matsushita Y.
Published: March 2019

Precision lattice parameter measurement by the X-ray diffraction method of Bond [1] has been examined as a substitutional method for IR in determining the oxygen concentration in silicon single crystals. Asymmetric 444 CuKai reflections were measured for undoped (100) oriented silicon wafers to obtain the correlation curve between the silicon lattice parameter and oxygen concentration. Precise adjustment of the optical system and computer fitting in determining the peak position allow a minute lattice dilation of silicon due to oxygen to be detected by the Bond method. The precision of this measurement system was of the order of 10-6. The lattice expansion of silicon by dissolved oxygen was determined to be at the rate of 3.2X10-24 atoms of oxygen per cm3. Furthermore, the oxygen concentrations of heavily Sb-doped silicon wafers were determined nondestructively.
An Expert System for the Validation and Interpretation of X-ray Residual Stress Data
Authors: Tricard Marc , Hendricks Robert W. , Guillot Marc
Published: March 2019

Although widely recognized in the research community as one of the most accurate non-destructive methods for the determination of . residual stress in polycrystalline structural materials, x-ray diffraction has not been widely adopted in the field. This is partly due to the fact that such measurements require, most often, a well trained user with knowledge in both materials and mechanical sciences in addition to the specific know-how of the instrument. We believe that computer assistance could contribute to the promotion of this technique by increasing the productivity and accuracy of these measurements. We have developed a prototype expert system, using Nexpert Object's shell, to assist a non-trained operator in the validation and interpretation of X-ray diffraction residual stress data.

The present work describes this prototype which has been designed to confirm the feasibility of the concept. Its knowledge base contains relevant examples of the rules necessary for data validation. The prototype has also confirmed most of the concepts required for the implementation of a full-scale version by evaluating all of the major technical features such as graphics representation, external routines and database access.