bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of YBa2Cu3O7-δ Peritectic Reactions and Orientation by High Temperature XRD and Optical Microscopy
Authors: Snyder R. L. , Rodriguez M. A. , Chen B. J. , Matheis D. P. , Göbel H. E. , Zorn G. , Seebacher B.
Published: March 2019

Real time observations of the YBa2Cu3O7-δ (123) melting process by high temperature XRD and optical microscopy reveal a reaction sequence which does not correspond well with the literature. CO2 gas, present in the air, reacts with 123 to produce the Y2CU2O5 phase. This reaction begins well below 800°C and persists up to 970°C when BaCuO2 begins to form. The previously unreported BaCuO2 reaction occurs in either air or oxygen and this phase grows at the expense of the 123 until both rapidly disappear at 1050°C with the appearance of Y2B2CuO5 (211), Formation of Y2O3 from the 211 melt occurs more slowly, beginning at 1150°C. Dynamic 00ℓ orientation has been observed at 950°C upon cooling from the melt. The orientationa) growth is believed to be a surface tension dependent, liquid assisted sintering reaction.
Nonlinear Equations for High Accuracy X-Ray Crystal Orientation
Authors: Dragoi Danut
Published: March 2019

Nonlinear equations are given for determining the crystallographic orientation of surfaces of single crystals. The equations are solved by an iterative method in several variables. The angle ϕ between the surface plane and the lattice plane in question is decomposed into two components α and β. These two components are obtained from the solution of a non-linear system of equations using two measurements and the Bragg angle. The diffractometric system considered is the well known θ/2θ with a sufficiently large area of x-ray detection and the capability of holding single crystal samples. The results obtained are discussed from experimental and theoretical points of view.
Solid-State Room-Temperature Energy-Dispersive X-Ray Detectors
Authors: Dabrowski Andrzej J.
Published: March 2019

Over the last several years there has been growing interest directed toward high-resolution energy-dispersive x-ray detectors which operate at room temperature. The goal has been to develop a detector which combines the advantages of room-temperature operation characteristic of scintillation and proportional counters with the excellent energy resolution of silicon and germanium cryogenically cooled spectrometers. The elimination of the cryogenic coolant and the associated vacuum cryostat will permit the design and construction of really miniature and practically convenient x-ray detection systems which will find applications In already existing instruments as well as in various new fields.
A Statistical Comparison of Data Obtained from Pressed Disk and Fused Bead Preparation Techniques for Geological Samples
Authors: Dow Randall H.
Published: March 2019

The analysis of geological samples by x-ray fluorescence analysis is complicated by matrix effects and sample variability. Diluting the sample in a suitable matrix such as lithium tetraborate and then fusing it helps to reduce problems associated with sample inhomogeneities and reduces matrix effects considerably.

Unfortunately, many of the trace elements in the sample can be diluted below their detection limits by this technique. Pressing the ground powder into a hard disk avoids this problem and is less time consuming. Matrix effects can be very serious however, but can be calculated and compensated for by fundamental parameters programs.
Trace and Minor Element Analysis of Obsidian from the San Francisco Volcanic Field Using X-Ray Fluorescence
Authors: Sanders Suzanne C. , Zahrt John D. , Bell Graydon
Published: March 2019

Obsidian from eight localities in the San Francisco volcanic field of Northern Arizona was analyzed for 21 minor and trace elements (Ti, Mn, Fe, Co, Zn, Rb, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, W, Au, Hg, Th) usincf x-ray fluorescence analysis. All samples exhibited irregular analyzing surfaces. This was a more in-depth study of a previous study (1) in which a very small number of standards were used.

The data, in the form of intensity ratios relative to iron, were statistically analyzed and the trace and minor element patterns established. The obsidian clustered into four well-defined groups each consisting of two localities: Government Mountain/Obsidian Tank, Slate Mountain/Kendrick Peak, Robinson Crater/O'Leary Peak, and RS Hill/Spring Valley. The four distinct groups were treated individually to refine the separation between the similar sites. Classification function coefficients were calculated for each locality, then used to identify the source of thirteen obsidian artifacts recovered from a Northern Arizona archaeological site.
Some Elemental Determinations of Catalytic Materials Using a Thin-Film Internal Standard Technique by Radioisotope Excited X-Ray Fluorescence
Authors: Parker W. C. , LaBrecque J. J.
Published: March 2019

Applications of some selected elemental determinations of different catalytic materials by radioisotope excited x-ray fluorescence will be presented. The analytical method, an improved sample preparation and analysis technique were presented at the last Denver Conference (1). Data on the accuracy and precision of each of the following types of catalysts are presented. 1) Platinum catalysts (0.5 - 10% Pt) on alumina and carbon supports used for dehydrogenation, hydrohalogenation, oxidation processes, etc. 2) Palladium catalysts (0.5% - 10% Pt) on alumina and carbon supports employed for alkylation, decarbonisation, hydrogenation, etc.
Direct Analysis of Plutonium Metal for Gallium, Iron and Nickel by Energy Dispersive X-Ray Spectrometry
Authors: Bramlet H. L. , Doyle J. H.
Published: March 2019

An x-ray secondary target method for routine determination of gallium, iron, and nickel in plutonium metal is described that has significant advantages over wet chemical analysis. Coupons requiring minimal preparation for analysis are produced as a breakaway tab on the plutonium ingot. All three elements are determined on the same coupon. Gallium is determined using an arsenic secondary target followed by iron and nickel using a zinc target. The analysis times are 5 minutes for gallium and 15 minutes for the combined iron and nickel. The method of analysis was evaluated in the range of from 0.5 to 1.5% gallium. Iron was investigated over the range of 67 to 3000 ppm and nickel from 64 to 110 ppm.
The Analysis of Copper Alloys by Chem-X, Low Power WDX Multichannel Spectrometer
Authors: Lucas-Tooth J. , Adamson B. W. , Gurvich Y. M.
Published: March 2019

The analysis of copper alloys is a classical case for X-ray fluorescence as an analytical technique. For many years, large wavelength dispersive X-ray spectroraeters have been used in process control associated with the manufacture of brasses, bronzes and coinage alloys. For the last two to three years, a new, benchtop WDX multichannel spectrometer, the Chem-X, has been successfully introduced for the same purpose.
X-Ray Fluorescence Analysis of Welding Fume Particles
Authors: Carsey Thomas P.
Published: March 2019

The technique of x-ray fluorescence is ideal for the analysis of metal fumes such as are produced in various welding and brazing operations. Although the constitution of welding and brazing fumes is dependent on the nature of the base metal, flux, and welding material used, they typically contain the oxides of iron, nickel, chromium, and manganese (stainless steel welding). The fumes are in the form of very small particles, usually 1.0 um, and are often agglomerated into long chains. Filter samples of these fumes, as are used in industrial hygiene monitoring, may contain 30-300 ug/filter of particles on one surface of a low-mass, 37-mm membrane filter.
Automatically Correcting for Specimen Displacement Error During XRD Search/Match Identification
Authors: Schreiner Walter N. , Jenkins Ronald
Published: March 2019

Over the past several years there has been considerable interest in computer search/match programs for qualitative analysis of powder diffraction patterns. This interest has been stimulated by the availability of modern minicomputers supported by relatively inexpensive mass storage devices capable of containing the entire JCPDS (l) data base on line. As the traditional search/match algorithms have been reviewed for possible implementation on the slower speed and restricted memory minicomputers being supplied with today's automated diffractometers, new ideas have emerged for such algorithms. One very extensive set of new algorithms has been developed by our group and these are contained in the SANDMAN search/match/identify program which was described at this conference last year (2). Experience has shown those algorithms to be extremely effective, particularly in handling eases where the presence of systematic errors in the data has precluded the correct analysis by other computerised search/match systems.
Observation of an X-Ray Beam 10 Microradian Divergence Without Using any Collimator
Authors: Gupta K. Das
Published: March 2019

I report the experimental setup to obtain an x-ray beam from germanium monocrystal of unusually small angle of vertical divergence of the order of 2 sec. of arc without using any collimator. The production and the properties of the highly collimated beam of x-ray will be described. A rectangular piece of germanium 1” × 1” and of thickness 0.5 mm has been cut with specific orientation of crystallographic planes (111) and (110). The 1” × 1” surface is parallel to (111) planes and the surface of one edge is parallel to (110) planes suitable for Borrmann channelling via (220) planes.
Stress Measurement and Precision Diffraction Angles on Large Grained Specimens
Authors: Barrett Charles S.
Published: March 2019

This note describes a diffractometer technique that is successful on specimens that yield sharp diffraction peaks but that have grain sizes somewhat too large to give reliable results with the usual powder diffraction methods, owing to the peak profiles being distorted or displaced by having too few grains reflecting, Such specimens are not uncommon in stress analysis and the errors encountered are sometimes reduced by oscillating the specimen through an angle range, Δβ, of a degree or so about the diffractometer axis, thereby increasing the number of recorded reflections. The technique discussed here is basically a single crystal technique rather than a powder technique, and with a diffractometer capable of measuring reflections at high angles on both sides of the initial beam this technique would amount to W. L. Bond's precision method. For the usual diffractometer, however, high diffraction angles must be measured on one side only, even though some instruments permit the lower angle reflections to be measured on both sides for accurately locating the zero of the 2θ scale. We are discussing a technique as applied to these usual types of diffractometers.
The Use of Energy Dispersive Diffractometry to Measure the Thickness of Metal and Glass Thin Films
Authors: Stone Glen A.
Published: March 2019

This paper presents a new method to measure the thickness of very thin films on a substrate material using energy dispersive x-ray diffractometry. The method can be used for many film-substrate combinations. The specific application to be presented is the measurement of phosphosilicate glass films on single crystal silicon wafers.
Application of Automated X-Ray Diffraction to Alteration Mineral Zoning Studies
Authors: Salek H. , Vincent H. A. , Thorpe L.
Published: March 2019

The purpose of this study was to develop a quick and valid X-ray method to determine the alteration models for acidic and intermediate type of altered rocks. Four alteration minerals--alunite, kaolinite, montmorillonite, and sericite--and total quartz in certain altered porphyritic rocks were determined and evaluated by using the APD (Automatic Powder Diffractometer) system with external standard methods.

The findings indicate that the APD system can successfully be used in the quantitative analysis of these five mineral phases. The best results are obtained from samples with low iron minerals and of a grain size not coarser than 325 mesh.
Evaluation of Macro- and Micro-Residual Stresses on Textdeed Materials by X-ray, Neutron Diffraction and Defection Measurements
Authors: Hauk Viktor M.
Published: March 2019

To evaluate the state of macro- and micro-residual stresses in cold rolled materials of 0.2 to 3 mm thickness the following test methods were used: Measurements of lattice spacing in different directions (φ,Ѱ)with X-rays and neutron-rays on many diffraction peaks. The X-ray method was employed on the surface of the sheet and of the thinned piece after removing several layers from both sides. The neutron-ray method allows measurements in the interior of a specimen and the average of the strain distribution of the total cross section. The etching deflection method determines the macro-residual stresses. The calculation of the macro- anci micro-residual stresses using X-ray elastic constants (XEC) for polycrystalline material and the compliances of single crystals for groups of grains are described. Homogeneous and heterogeneous materials like steels, (α + β)-brass, nickel and copper with 3 % silver were investigated. The state of residual stresses on the surface and with the depth over the cross section was evaluated or is in the final process of investigation.
X -Ray Elastic Constants and Their Meaning for Al and Fe
Authors: Zhong Rui Mei , Noyan I. C. , Cohen J. B.
Published: March 2019

In the measurement of residual stresses via diffraction (using x-rays or neutrons) it is strains that are actually determined, by employing the interplanar spacing (dhkl) of the ﹛hkl﹜ planes as an internal strain gauge. The change in this spacing is measured from the shift of diffraction peaks (and Bragg's law) at several orientations of the sample to the incident beam, and the resultant strains are converted to stresses with the “diffraction elastic constants”, S1 (hkl) and S2 (hkl)/2. While these take on the values (- v/E) and (1 + v )/E respectively for an isotropic solid, in anisotropic materials their values depend on marry factors: preferred orientation, shape and orientation of second phases, interaction between grains. In fact there are reports of variation these constants with plastic deformation and theory predicts variations with morphology. While it is possible to calculate approximate values for these constants from theory and the single crystal elastic constants , Si and S2/2 are really not elastic constants in the strictest sense because or these other factors, and it is best to measure them. One of us (I. C. Noyan) has recently examined this problem in some detail , and we summarize his results here.
X-Ray Stress Analysis of Nickel-Plated Components Using Different Radiation Wavelengths
Authors: McSwain R. H. , Pardue E. B. S. , Hendricks R. W. , Mathis M. V.
Published: March 2019

X-ray stress analyses were performed on seven (7) nickel-plated camshafts from helicopter transmissions. The purpose of this investigation was to determine if this residual stress technique was useful in determining the state of stress in load-bearing plated surfaces of critical reworked aircraft components. Specifically, it was desired to characterize six different stages of nickel plating processing. These were: as-plated, plated and baked, machined, machined and baked, ground, and ground and baked. Three different radiation wavelengths with different penetrations were used In this investigation. CrKα , CoKα , and CuKα, radiations were each used on all of the camshafts. These wavelengths were selected to determine if there were stress gradients in the plated layers. This paper presents and discusses the results of these studies.
X-Ray Stress Determination in a Single Lap- Joint Containing a Debonded Region*
Authors: Lankford A. , Barrett C. S. , Predecki Paul
Published: March 2019

XRD has been found to be a useful technique for investigating both surface and interior stresses in. adhesive bonded joints. For the interior stresses, to gain access to the joint interface, adherends were chosen such that one adherend was relatively transparent to the X-radiation used and the other was not. Incident X-rays then penetrated the first adherend and the adhesive, and were diffracted from just below the surface of the second adherend.

In prior work it was shown that the measured stresses due to an applied load agreed quite well with stresses calculated for the same joint using the TEXGAP-2D finite element program, except at one extremity of the bond. One explanation proposed for the discrepancy was that a small debond was present at this extremity. In the present study, therefore, an investigation was made of a joint contfli'nitig an intentional debond at this extremity.
Errors due to Counting Statistics in the Triaxial Strain (Stress) Tensor Determined by Diffraction
Authors: Rudnik P. , Cohen J. B.
Published: March 2019

Knowledge of the errors in a diffraction measurement of residual strains and stresses is useful information, not only in its own right, but also because it permits automation of a measurement to an operator-specified precision. There are three sources of these errors.
XRDQUAL-- A Probalistic and Least Squares Search/Match Procedure
Authors: Clayton William R.
Published: March 2019

A series of computer programs have been written (collectively called XRDQUAL) for automated identification of XRD patterns. The algorithms used in XRDQUAI, have been selected for maximum compatibility with computerbased calculations and decisions, XRDQUAI relies heavily on probabilistic logic and calculations. The overall sequence used can be divided into three general steps.
Clay Minaeral Analysis by Automated Powder Diffraction Analysis Using the Whole Diffraction Pattern
Authors: Smith Deane K. , Johnson Gerald G. , Ruud Clayton O.
Published: March 2019

Clay minerals are one of the most difficult classes of materials to analyze by x-ray powder diffraction, yet powder diffraction is the only technique which can yield the important crystallographic information necessary to identify and classify the minerals. The importance of clay minerals in industry and in the studies of rocks, due to their chemical properties and sensitivity to geological changes, often requires the analyses of large numbers of samples in short periods of time. Such sample throughput requires computerized analysis* Because definitive, meaningful d-I data are difficult to obtain from the broad diffraction peaks obtained from most clay samples, this problem has been approached by using the whole diffraction, trace as the basis of a computerized analytical scheme.
X-Ray Measurement of Residual Stress Near Fatigue Fracture Surfaces of High Strength Steel
Authors: Hirose Yukio , Tanaka Keisuke
Published: March 2019

The residual stress left on the fracture surface is one of the important parameters in X-ray fractography and has been used to analyse fracture mechanisms in fracture toughness, stress corrosion cracking and fatigue tests especially of high strength steels.

In this study, the distribution of residual stress near fatigue fracture surfaces made in air and in 3.5% NaCl solution was measured by the X-ray diffraction method. The effect of aqueous environment on the plastic deformation near fatigue fracture surfaces was discussed on the basis of the residual stress distribution.
Determination of Crystallinity in Graphite Fiber-Reinforced Thermoplastic Composites
Authors: James M. R. , Anderson D.P.
Published: March 2019

Interest in advanced thermoplastic composites for use in high performance structures stems from their order of magnitude improvement in fracture toughness and delamination resistance over epoxy based composites, their strong solvent resistance, and the possibility of dramatically lower fabrication costs through processing flexibility. The chemical and mechanical properties of semicrystalline thermoplastics depend on the morphology of the material, such as the crystallinity content and spherulite size. We describe here the use of x-ray diffraction to characterize the degree of crystallinity of the polyetheretherketone-graphite composite system, a leading thermoplastic candidate for use in aerospace vehicles. In reflection, diffraction from the microcrystalline graphite fibers dominates the scattered signal and must be adequately accounted for. The technique is useful on large samples and for quality control. In transmission, the graphite signal is weak, thus simplifying data analysis; however, sample thickness must be limited.
Structural Examination of Iridium-Based Single-Crystal Preparations
Authors: Axler K. M. , Roof R. B.
Published: March 2019

A high-temperature crystal growth experiment produced discrete singlecrystal products of Allr and IrSi. The preparation, and examination of these phases is described within. This project is part of a materials compatibility study relating to radioisotopic heat sources. These heat sources are comprised of a PuO2 fuel pellet encapsulated in an Ir alloy containment shell. Thorium is introduced as an additive within the Ir to maintain ductility. Si and P are picked up inadvertently in the fuel processing. The compatibility of the heat sources with Al is of interest because of potential interactions with the Al alloy hardware associated with the heat source environment.
Assessment of Multiple Epilayer III-V Compound Semi-Conductors by Synchrotron Radiation Diffractometry
Authors: Bowen D. K. , Davies S.T. , Swaminathan S.
Published: March 2019

An extensive programme of characterization of optoelectronic device material has been performed at the Synchrotron Radiation Source, Baresbury Laboratory, in collaboration with Plessey Research, Caswell. The material was grown by Plessey Research by liquid phase epitaxy on InP substrates and had quaternary active layers with, usually, four epilayers in total. Some specimens had graded epilayers. This paper reports use of the methods of double crystal topography, rocking curve analysis and simulation, selective etching and Talysurf measurement in order to develop and assess non-destructive methods of evaluation. The destructive methods above were therefore used in order to test and verify the non-destructive X-ray techniques.
X -Ray Topography of Ion - Implanted Laser -Annealed Si
Authors: Dragsdorf R. D. , Bhalla C. P.
Published: March 2019

The introduction of various atoms into crystal surfaces by ion implantation has become common practice in the research laboratory and in many industrial processes. The deceleration of the introduced foreign ions during implantation results in extensive lattice damage. Atom displacement from equilibrium crystal sites and pile-up of the new atoms take place. The use of the pulsed laser for annealing these atomic defects in a single crystal is well documented . The absorption of the total energy in the laser pulse can be rapidly transferred to the lattice, approximately 10-9s, for an elevated temperature anneal of the damaged crystal. The photon energy of the monochromatic laser beam can be tailored so that the absorption of the radiation by a specific crystal can “be matched for its penetration into the crystal to that of the depth of the implanted atoms. A highly efficient mechanism is thus utilized to anneal just that portion of the crystal which is damaged by the impinging atoms of the implant.
X-Ray Fluorescence Analysis of Multi-Layer Thin Films
Authors: Huang T. C. , Parrish W.
Published: March 2019

The characterization of multi-layer thin films by X-ray fluorescence using the fundamental parameter method and the LAMA-III program is described. Analyses of a double-layer FeMn/NiFe and two triple-layer NiFe/Cu/Cr and Cr/Cu/NiFe specimens show that the complex inter-layer absorption and secondary fluorescence effects were properly corrected. The compositions and thicknesses of all layers agreed to ±2% with corresponding single-layer films, a precisian comparable with bulk and single-layer thin film analyses.
Multilayer Scatterers for Use in Polarized X-Ray Flourescence
Authors: Zahrt John D. , Ryon Richard W.
Published: March 2019

In the EDXRF analysis of minor and trace elements in a variety of matrices, the use of a polarized x-ray source incident on a sample will provide minimum detection limits three to five times lower than the use of non-polarized sources (1,2). There are various methods of producing monochromatic polarized x-rays for specimen excitation (3,4,5,6 ). Such x-ray sources may produce the lowest detection limits for a single element or a narrow range of elements. However, if one is interested in simultaneously analyzing a broad range of elements, a polychromatic source is desired (7,8,9). We present here a new method for producing broad-band polarized x-rays.
A Universal Data Base Approach For Quantitative WDXRF Analysis With General Purpose Data Acquisition Algorithms
Authors: Rokosz M. J. , Artz B. E.
Published: March 2019

Acquisition of new x—ray fluorescence (XRF) hardware or a data reduction computer can be a particularly frustrating experience for analysts who depend upon programs not supplied by the XRF spectrometer manufacturer. Computerized data collection and reduction pragrams generated for a particular spectrameter/computer system can become virtually useless when a significant part af the spectrometer/computer system is replaced. The problem is compounded in a research environment where many different kinds of samples are encountered and many unique analysis programs developed.

The potential magnitude of this problem was recently demonstrated at the Ford Motor Company Scientific Research Laboratory when the thirteen year old computer-contolled XRF analysis system was replaced by a new state-of-the-art spectrometer/computer system.
The Recessed Source Geometry for Source Excited X-Ray Fluorescence Analysis
Authors: Conde C. A. N. , dos Santos J. M. F.
Published: March 2019

Different geometries are considered for source excited energy-dispersive X-ray fluorescence (EDXRF) analysis Systems, including the recessed source geometry introduced in the present work. The calculated physical excitation-detection efficiencies, for the side (or annular), central, receded and recessed source geometries are presented as a function of the target to source distance, for Ca, K, S and Si targets excited with a Fe-55 XBF-3 X-ray source and xenon filled gas proportional scintillation counters. The last two geometries present in gênerai the highest efficiencies. The recessed source geometry présent the best performance with peak efficiencies a factor of 3.3 better than those for the standard side or annular source geometries.
Analysis of Refractory Materials by Energy Dispersive X-Ray Spectrometry
Authors: Parker Jim , Watson Wayne
Published: March 2019

Silica-alumina refractory materials are used as insulation materials in high temperature applications. Such materials are amenable to x-ray analysis (1). Wavelength dispersive x-ray spectrometry is used in our laboratory for the analysis of a variety of refractory materials. An analysis procedure was needed for a quality control project that would provide major and minor element determinations in silica-alumina refractory materials. The requirements for the analysis scheme were relative accuracy and precision to be better than one percent. The method had to be rapid, simple to use, and inexpensive. Energy dispersive x-ray spectrometry and a borate fusion technique were chosen as the method of choice for this application. Described in this paper are the sample and standard preparation procedures, data reduction methods, and analytical results.
Contamination of Silicate Rock Samples due to Crushing and Grinding
Authors: Tuff Mark A.
Published: March 2019

This study was done to learn which elements are being contributed as contaminants in the sample preparation equipment used at the New Mexico Institute of Mining and Technology (NMIMT). The apparatus investigated included a steel jaw crusher, a ceramic jaw crusher, two aluminum plates as a crusher and grinder, a steel spinning plate pulverizer, an alumina ceramic spinning plate pulverizer, an automated agate mortar and pestle, a high speed spectromill grinder with a tungsten carbide mortar and pestle, and the halves of a sliced quartzite cobble. Major-element Oxides and trace elements were analyzed by x-ray fluorescence. Some of the trace elements were analyzed by instrumental neutron activation analysis. The expected contamination of ferroalloy elements from steel were present in varying quantities, as were tungsten, tantalum and cobalt fron the tungsten carbide. There was unexpected contamination of sulfur and lead from the steel pulverizer.
A Fusion Method for the X-Ray Fluorescence Analysis of Portland Cements, Clinker and Raw Materials Utilizing Cerium (IV) Oxide in Lithium Borate Fluxes
Authors: Barger Gregory S.
Published: March 2019

This method describes the addition of cerium (IV) oxide to a lithium borate flux. CeO2 provides a non-analytic glass former to the melt production. CeO2 also acts as an interelemental buffer replacing the use of lanthanum oxide for long wavelength absorption. With cerium oxide addition, excellent results are produced, resulting in part from the elimination of recrystallization problems encountered with lanthanum oxide use. Analytical results easily meet the ASTM C-114 qualification requirements for rapid method analysis of hydraulic cements.
Application of Computers in Electron Probe and X-Ray Fluorescence Analysis
Authors: Rasberry Stanley D.
Published: March 2019

This paper is a review of automation of electron microprobe and x-ray fluorescence instrumentation. Such a review seems timely because of the great increase in the application of computer systems in this field over the past decade. Some of these applications have been conceived to meet true technological needs while in other cases they have “been undertaken to “keep up with the Joneses.” I would like to show not only what automated systems are now feasible but also when and how they should he employed. The “when” and “how” of automation are largely dependent upon the application being considered; in this study, x-ray applications have been divided into the following classes;

(1)

on-stream process-control,

(2)

off-line quality assurance,

(3)

routine service laboratory,

(4)

general purpose analytical laboratory.

Several phases are present in these classes, including: specimen preparation and loading, measurement, data acquisition and transfer, data processing and display, and finally, archival data storage. Various workers have undertaken the automation of all these operations in one or the other of the classes of applications; from a review of their work and by examining details of each operation within the framework of a given application, we can now draw conclusions on the extent of desirable automation.
Computer-Controlled X-Ray and Neutron Diffraction Experiments
Authors: Mueller Melvin H.
Published: March 2019

The use of on-line computers for control and acquisition of data from x-ray and neutron diffractometers has continuously improved and expanded. Systems vary from a small 4K core computer to a time-sharing system with a medium or large computer. The choice of a single time-shared computer or an individual standalone system must be based on one's own particular environment. As large high-speed electronic computers became available, increasingly complex chemical and magnetic structures have been analysed and solved; this has created a demand for rapid, reliable, and versatile means of obtaining diffraction data. Since small computers have been developed at reduced cost and with increased storage capacity, they must be considered for use in diffraction experimentation. Therefore, in x-ray and neutron scattering, small computers are needed for data acquisition and large computers are needed for data analysis.
Automated X-Ray Diffraction Laboratory System
Authors: Segmüller Annin
Published: March 2019

An IBM 1800 time-sharing system is used in our X-ray laboratory to control a four-circle diffractometer for structure research, several powder diffractometers, a pole-figure goniometer and a microdensitometer along with other instruments outside the diffraction area. A survey of the computer system is given and the hardware necessary to automate the diffractometers is discussed. The computer supervision ranges from simple data-logging with a minimum of control to complete control of all actions depending on the diffractometer and the requirements of the experiment. Also described is the use of the computer to process the data and to perform background jobs.
Determination of Zirconium, Hafnium, Niobium, Tantalum, Molybdenum and Tungsten in Aqueous Solutions by Radioisotopic Excited X-Ray Fluorescence
Authors: Chan Frank L. , Jones W. Barclay
Published: March 2019

Previous investigations on the quantitative determination of sulfur, chlorine, potassium, calcium, scandium and titanium in aqueous solutions by a radioisotopic excited fluorescent spectrometer has been extended to include other elements which are very difficult to separate and determine quantitatively by chemical methods. Six elements taken for the investigation and some of the results to be presented in this paper are:

(1)

zirconium,

(2)

hafnium,

(3)

niobium,

(4)

tantalum,

(5)

molybdenum and

(6)

tungsten.

As in previous investigations, aqueous solutions have been used because of the ease in obtaining exact concentrations and homogeneous mixtures of the elements under investigation.

In the earlier investigations which have been reported in this conference, lighter elements (atomic numbers ranging from 16 to 22) were used for the investigation. In the present studies, however, comparatively heavier elements have been used. Therefore a radioisotope such as iron 55 used earlier is not suitable because it cannot excite the K x-ray of these elements. To excite the K and L of these elements, we use the radioisotope iodine 125. The advantage of using this radioisotope is that it is inexpensive and commercially available although its half-life is comparatively short.

The spectrometer used with further improvements has been described and presented earlier. We used a multi-channel analyzer of 1000 in the present investigation, A liquid cell was specially designed for thisr study. Chemicals used for preparation of solutions were of reagent grades. Some of them had to be specially prepared. For example, hafnium, often contaminated with zirconium, was specially prepared and checked spectroscopically. Some difficulties have been encountered in preparing concentrated solutions such as niobium and tantalum due to the inherit characteristics of these elements to form insoluble compounds. Procedures will be described for the preparation of these solutions. Instruments used and results will be presented in this paper.
A Complete Instrumental System for Energy Dispersive Diffractometry and Fluorescence Analysis
Authors: Martin G.W. , Klein A.S.
Published: March 2019

A system, has been designed and tested for rapid energy dispersive diffractometry and simultaneous fluorescence analysis. A turntable composed of the sample chamber with attached air-cooled x-ray tube allows the 2θ angle to be varied with respect to the stationary Si(Li) detector. Data for most analyses can be obtained in one minute per sample. Results are stored in the memory of a multichannel analyzer and are read out on a CRT, strip chart recorder or tabulated in digital format by a computer.
The Use op Field Emission Tubes in X-Ray Analysis
Authors: McCrary J. H. , Vorous Ted Van
Published: March 2019

Recently developed, miniature, steady state, field emission tubes are finding application in several areas of x-ray analysis. These tubes require only a high voltage, low current power supply to produce relatively intense beams of x-rays. Since anodes can be fabricated from almost any element, and since the tubes can be operated at potentials up to about 70 kV, many different output x-ray spectra are available. Miniaturized battery operated x-ray sources of this type, occupying a volume of about one liter, have several advantages over radioisotope sources. These include cost, safety, and controllable output spectra and intensity. X-ray sources for energy dispersive fluorescence analyzers are designed so that no scattered characteristic radiations will interfer with the analysis of the sample fluorescence. Sources which are essentially monoenergetic can be fabricated for use in non-dispersive x-ray fluorescence analyzers. Because of the intensity and safety of the field emission tubes, such analyzers can be made which are sensitive while compact, portable, and inexpensive. In x-ray absorption analysis the measurement of absorption edge jump ratios provides a quantitative measure of sample impurities. Field emission tubes whose output spectra consist primarily of bremsstrahlung are particularly well suited to such measurements. The techniques involved in using these tubes in x-ray analysis are described.
Analysis Of Solid Surfaces By Soft X-Ray Appearance Potential Spectroscopy
Authors: Park Robert L. , Houston J. E.
Published: March 2019

The total soft x-ray emission of an electron-bombarded surface exhibits abrupt changes at the threshold potentials for the excitation of core levels of surface atoms. These features represent the excitation probabilities of the core states superimposed on a smoothly increasing background and can be sensitively detected by differentiating the x-ray emission with respect to sample potential. The application of this technique to the study of surface composition, chemical shifts, and band structure is discussed.
The Measurement of Surface-Layer Stresses in a Polycrystalline Glass by Means of X-Ray Diffraction
Authors: Karamer E.W. , Void C.L.
Published: March 2019

Many glass materials can be made more resistant to failure if the surface layers are in a state of permanent compressive stress. For purposes of monitoring production quality at the factory, as well as to verify compliance with specifications before incorporation into special devices, it is desirable to measure nondestructively this stress magnitude. For those glass compositions in which the stress generating process creates a residual, finely divided, and uniformly dispersed crystalline phase (e.g. “Pyroceram“), a stress measuring technique based upon X-ray diffraction has been adapted and successfully used. Lattice spacings for near-surface crystallites are determined under the stressed conditions present in the final glass product. These lattice spacings are compared with values obtained from a powdered sample of the identical glass composition. In the powdered state the induced stress effects are minimal. Hence, the shift in lattice spacings is a measure of the compressive surface stress level attained in the manufacturing process.
Simultaneous Spiral Recording of Pole Figures on Polaroid Film for Texture Goniometers
Authors: Ebel H. , Ebel M. F.
Published: March 2019

The X-ray reflection method according to Schulz is used for investigations of textures in rolled materials. The pole figures are measured either along spirals or along circles. Points of equal intensity are transposed from the record of X-ray intensity to a spiral diagram. Finally contour lines are delineated, pointing out regions of equal pole density. Three ways are known for simplification of the evaluation.

a)

The results of the measurement are stored, evaluated by a computer and the pole figure is plotted. Points of equal pole density are represented by equal symbols (2 ,3 ).

b)

The pole figure is recorded synchronously with the X-ray measurement along circles or spirals. Ranges of different pole density are characterized by different colors (4 ,5 ).

c)

The pole figure is recorded on a photographic film along a spiral. The blackening depends on the measured countrate (6 ,7 ).

An outline on different instruments using photographic registration is given.
Light Element Analysis
Authors: Baird A. K.
Published: March 2019

Qualitative and quantitative analyses of elements below atomic number 20, and extending to atomic number 4, have been made practical and reasonably routine only in the past five to ten years by advances in: 1) excitation sources; 2) dispersive spectrometers; 3) detection devices; and 4) reductions of optic path absorption. At present agreement is lacking on the best combination of parameters for light element analysis. The principal contrasts in opinion concern excitation.

Direct electron excitation, particularly as employed in microprobe analysis (but not limited to such instruments), provides relatively high emission intensities of all soft X-rays, but also generates a high continuum, requires the sample to be at essentially electron gun vacuum, and introduces practical calibration problems (“matrix effects“). X-ray excitation of soft X-rays overcomes some of the latter three disadvantages, and has its own limitations. Sealed X-ray sources of conventional or semi-conventional design can provide useful (if not optimum) light element emission intensities down to atomic number 9, hut with serious loss of efficiency in many applications below atomic number 15 largely because of window-thinness limitations under electron bombardment.
A Vacuum Spectrometer for Studying the Chemical Effect on Soft X-Ray Spectra
Authors: Baun W. L. , White E. W.
Published: March 2019

Soft X-ray spectroscopy promises to be one of the most powerful techniques for solving a wide variety of materials characterization problems. Although chemical analysis of the light elements is commonly done by the electron microprobe and X-ray fluorescence, the “chemical effect on X-ray spectra” has been utilized in relatively few cases. This appears to result from a general lack of appreciation for the applicability of chemical effect measurements and perhaps to a greater extent it is due to the unavailability of appropriate soft X-ray spectrometers. Most studies have been carried out using instruments that were not particularly well suited to chemical effect studies. The purpose of this paper is to describe a versatile new soft X-ray spectrometer and auxiliary equipment for the study of the chemical effect. The spectrometer is housed in a versatile, high vacuum chamber 24 inches in diameter by 4 5/16 inch vertical clearance.
X-Ray Interaction Coefficients: Effect on Interpretation of Solar X-Ray Data
Authors: Blake R. L.
Published: March 2019

The interpretation of solar x-ray data obtained from KAP crystal spectrometers requires new laboratory measurements. We used a plasma x-ray source and a KAP spectrometer similar to solar spectrometers and measured the following.
IEE - A New Type of X-Ray Photoelectron Spectrometer
Authors: Weichert N. H. , Helmer J. C.
Published: March 2019

A new type of x-ray photoelectron spectrometer has been designed. Although smaller in size, the new instrument shows a considerable improvement in sensitivity compared to other photoelectron spectrometers. This has been achieved through the provision of several new features: The photoelectrons are retarded to low energy (10 eV through 100 eV) before entering the deflecting energy analyzer. A spherical electrostatic analyzer in figure of rotation is used. Annular slits at both source and detector provide a large effective source area. The instrument is shielded against external magnetic fields (earth magnetic field and a.c. fields) by a double layer of mu-metal, thus avoiding the installation of large Helmholtz coils.
α- Excited Auger Spectra
Authors: Yin L. I , Adler L. , Lamothe R. E.
Published: March 2019

The possibility of obtaining Auger spectra excited by a Po 210 α-source has been investigated. The obvious advantages in the use of radioactive α-sources are simplicity, stability, and high ionization cross section for light elements. Typical spectra obtained with this method, as well as parameters affecting the characteristics of these spectra, are presented and discussed The following observations have been made: the intense low energy continuum background make it difficult to detect the presence of Auger lines in this region; the abundance of Auger lines in the above region makes identification difficult; the intensity of higher energy Auger lines is too low to be observed with the present α-source and low vacuum system; thus the practicability of α-excited Auger spectroscopy will need further investigation.
On the Symmetry of Orientation Distribution in Crystal Aggregates
Authors: Baker David W.
Published: March 2019

In a number of laboratories data from the X-ray pole-figure goniometer are now processed numerically to obtain a suite of complete and normalized pole- figures. From these pole-figures the preferred orientat ion of the grains in a monomineralic aggregate is determined using spherical harmonic analysis and represented as a frequency distribution of the Euler angles Ψ, θ, ø, termed the “orientation distribution function” (ODF),When the frequency density of grain orientations is plotted in a Cartesian coordinate system with Ψ, θ, ø, as axes,it must have a translation periodicity Of 2π or less along each of the axes, because the Euler Angles are angles of rotation.
Forty Years of Quantitative Diffraction Analysis
Authors: Alexander Leroy E.
Published: March 2019

In this paper an attempt is made to review in rather broad perspective the origins and history of quantitative methods in diffraction analysis, at the same time leaving an in-depth examination of the present state of the art to other better qualified contributors to this conference. Space limitations preclude mention of many significant contributions, for which I am very sorry. It will be possible to review only a number of pivotal historical events, while also taking note of certain other researches that seem representative of historical and present-day trends.

The birth of quantitatively meaningful analysis in the mid-1930s depended upon a realisation of, and allowance for, the alteration of the diffracted intensities resulting from absorption of x-rays by the specimen. Furthermore, advances in the art achieved during the past forty years have been closely related to improvements in the treatment of the absorption factor.
X-ray Diffraction Examination of the Phases in Expansive Cements
Authors: Mather Katharine
Published: March 2019

Beginning in December 1968, Type K expansive cements of both the shrinkage-compensating and self-stressing types, particularly ChemStress (a self-stressing cement) have been tested, and examined by X-ray diffraction in the Concrete Laboratory of the U. S. Army Engineer Waterways Experiment Station. They are interesting subjects for the study of mixtures by X-ray diffraction because they may contain as many as 14 identifiable phases, including most of the phases in portland cement. Their examination by X-ray diffraction is greatly assisted by chemical treatments, first with maleic acid in methanol, followed by treatment with ammonium chloride solution to remove the calcium sulfates and leave a residue that consists of tetracalcium trialuminate sulfate, quartz, corundum, and a few very minor substances which have proved to be unidentifiable.
X-ray Diffraction Examination of Coal Combustion Products Related to Boiler Tube Fouling and Slagging
Authors: Mazza M. H. , Wilson J. S.
Published: March 2019

The Morgantown Energy Research Center of ERDA is studying fouling and slagging of pulverized coal fired boiler tubes resulting from mineral matter contained in the coal. The research is dependent on the development and application of reliable analytical techniques which can be applied to the coal and ash products to determine the mineral interactions responsible for fouling and slagging. X-ray powder diffraction is one of the techniques used to characterize the feed coals and their combustion products. A summary of the methods and techniques applied at MERC is the subject of this paper.