bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Application of X-Ray Diffraction Method to the Measurement of Crystal Deformation and Crystal Modulus of High Polymers
Authors: Nakamae Katsuhiko , Nishino Takashi 
Published: March 2019

AbstractElastic modulus EI of crystalline regions of various high polymers in the direction parallel to the chain axis were measured using an X-ray diffraction method. The crystal deformation can be detected directly by the diffraction peak shift as a function of applied constant stress. The stress in the crystalline regions is assumed to be equal to that applied to the specimen. The validity of this assumption has been proven experimentally for polyethylene, poly(p-phenylene terephthalamide) and so on. The EI values were discussed in relation to molecular conformation and deformation mechanism of the chains.
Analysis of X-Ray Diffraction Data for the Characterization of Residual Stress
Authors: Park Jun S. , Shackelford James F. 
Published: March 2019

AbstractThe analysis of linear dϕψ vs sin2ψ x-ray diffraction data in isotropic single phase materials was investigated for the evaluation of x-ray elastic constants. This study developed an experimental model for estimating x-ray elastic constants based on the analysis of biaxial residual stress states, A ball bearing steel and a 1018 steel weldment were evaluated.In a second study, the measurement of residual stress gradients was evaluated for those depth ranges mat can not be evaluated with a single radiation. This requires various planes and radiation energies to obtain the simultaneous conditions of high diffraction angle and large x-ray penetration depth. The evaluation of the overlapped stress gradient region is illustrated in terms of x-ray energy and diffraction angle for the ease of iron. This analysis is specifically developed for the purpose of stress gradient measurement using synchrotron radiation.
Characterization of Ferroelectric PZT Thin Films - Line Broadening Study (Using Grazing Incidence Geometry)
Authors: Eatough Michael O. , Goehner Raymond P. , Headley Thomas J. , Tuttle Bruce A. 
Published: March 2019

AbstractFerroelectric polycrystalline thin films are being pursued as materials for use in the next generation of radiation hardened nonvolatile semiconductor memories, optical switches and optical computers. Of particular interest are PZT films with a composition near the morphotropic phase boundary. In order to fully understand the the difference in electrical properties as a function of processing parameters it is necessary to fully characterize phase composition and crystallographic properties of these films. Since some films are produced by either spinning or dipping successive layers to obtain the desired thickness it was necessary to compare the properties of each layer.X-ray diffraction techniques employing parallel beam optics with grazing incidence angle geometry were used to characterize the films. Experimental procedures using sealed tube xray diffraction systems to determine differences in crystallite size and microstrain as a function of depth into the films are a rather unique application of this technique. Discerning the contribution to line broadening due to phase changes, grazing incident angle geometry, crystallite size and microstrain are key to the success of this technique.This paper discusses the experimental techniques employed and will demonstrate how we were able to successfully determine microstrain as a function of depth into the film. We use transmission electron microscopy (TEM) to aid in the characterization of the films. A brief description of the processing procedures used to produce the films is also provided.
Numerical Calculation of Axial Divergence Profiles
Authors: Coyle R. A. 
Published: March 2019

AbstractThe diffractometer instrumental profiles convoluted by Alexander from aberration profiles calculated using the methods developed Easterbrook, Pike and Wilson include two profiles which are not amenable to exact analytical solution. These two profiles are generated by the axial divergence and flat specimen aberrations. Using ray tracing techniques the exact profiles of these two aberrations have been computed for the Philips PW1050 and Scintag DA5 diffractometers. sample profiles at 2θ = 28°, 90° and 152° have been convoluted with the third asymmetric profile, that due to specimen transparency, and plots of the resultant profiles are shown. Shifts of the centroids and the peaks of the profiles from the true Bragg angle have also been computed and plotted over the range 2θ = 0°-180°.
Oxidation/Reduction Melting Equilibria in the System BaO-½Y2O3-CuOx II. Powder X-Ray Analysis
Authors: Wong-Ng Winnie , Cook Lawrence P. 
Published: March 2019

AbstractX-ray powder diffraction together with several other analytical techniques have been used to characterize the phase formation and the melt compositions associated with the invariant reactions in the system BaO-½Y2O3-CuOx. In this report, the characterization results of the ternary eutectic reaction of the system, the melting of the high Tc compound Ba2YCU3O6+x, and the melting of the 'green phase' BaY2CuO5 are described. The minimum malting eutectic temperature of the system has been determined to be ≈ 925°C, which corresponds to the reaction of Ba2YCu3O6+x + CuO + BaCuO2 → Liquid. The melting of Ba2YCu3O6+x takes place at around 1015°C to yield BaY2CuO5 + Liquid. The green phase melts around 1270°C to yield BaY2O4, Y2O3 and liquid. All these melts were found to contain only a small amount of Y. Reduction of the copper was found to accompany melting.
“Whole Pattern” XRD Interpretation of Mineralogical Variation
Authors: Ferrell Ray E. , LaMotte Lynn R. , LeBlanc Wanda S. , Wilensky David E. , Mao Lin 
Published: March 2019

AbstractAll intensity data in a powder XRD pattern can be used to provide useful results for the interpretation of the mineralogical variability of geological samples. Simple statistical methods using Bonferroni's theorem permit the recognition of areas usually associated with mineral peaks where sample patterns are different at a predetermined level of confidence. Intensity/frequency histograms reveal subtle differences in low intensity regions of the XRD patterns that are also indicative of sample variability. These procedures facilitate the comparison of samples and may reduce the total analytical error because the weight percent determination can be eliminated.
The Gas Proportional Scintillation Counter as a Room-Temperature Detector For Energy-Dispersive X-Ray Fluorescence Analysis
Authors: Conde C. A. N. , Requicha Ferreira L. F. , Campos A. J. de 
Published: March 2019

AbstractA review of the basic physical principles of the gas proportional scintillation counter is presented. Its performance is discussed and compared with that of other room-temperature detectors in regard to applications to portable instruments for energy-dispersive X-ray fluorescence analysis. It is concluded that the gas proportional scintillation counter is definitely superior to all other room-temperature detectors, except the mercuric iodide (HgI2) detector. For large areas or soft X-rays it is also superior to the HgI2 detector.
Volatilization of Sulfur in Fusion Techniques for Preparation of Discs for X-Ray Fluorescence Analysis
Authors: Baker James W. 
Published: March 2019

The fusion technique for sample preparation for x-ray fluorescence analysis has been proven very successful for a wide variety of sample types. An inherent problem in the fusion technique has been the loss of sulfur during the fusion process. To extend our quantitative major element analysis method for geologic materials we have examined the problem of sulfur volatilization and have tested a variety of fluxes to determine their suitability to quantitatively retain sulfur during fusion, to produce a homogeneous glass disc that is suitable for presentation to an x-ray spectrometer with no additional sample preparation, and to help protect platinumware from attack by sulfide minerals.Highly oxidizing conditions are necessary both to retain sulfur and to protect platinumware from sulfide attack. Previous researchers have shown that sulfur may be lost under reducing conditions. All of the fusions in this study were performed in an oxidizing environment, using a muffle furnace.
A Versatile Minicomputer X-Ray Search/Match System
Authors: Parrish W. , Ayers G. L. , Huang T. C. 
Published: March 2019

AbstractThe operation of a new polycrystalline phase identification method using the IBM Series/1 minicomputer is described. Data of the unknown can be entered by automatic transfer of previous runs, stored data sets and manually. Full screen menu selections are provided to facilitate operations and correct entries. Typical S/M time for a multi-phase inorganic mixture containing 43 reflections using a 0.3° window averaged 11 sec per 100 standards and with simple chemical prescreening less than 4 sec including program initialization and calculations of comprehensive figures of merit. Interactive options provide graphics terminal comparison of the unknown pattern with selected standards which appear as diffractometer patterns, subtraction of identified standards from the unknown and others. Utility programs permit storing data sets for later analysis, user created files and a program to display any file standard as a diffractometer pattern.
Application of the Modified Snyder's Program for the Data Processing of an Automated X-Ray Powder Diffractometer
Authors: Platbrood G. , Quitin J. M. , Barten H. 
Published: March 2019

X-ray diffraction analysis is an excellent analytical tool. But if a certain quality of the results is needed or if solutions of analytical problems are to be obtained in a short time period, the X-ray diffractometer must be automated and the spectra reduced with dedicated algorithms.In LABORELEC, three programs are principally used to solve the problems encountered in the X-ray diffraction analysis: a modified program given by R. L. Snyder; the search/match G. G. Johnson program (last version); and the POWD5 program.
A Comprehensive Approach to in Situ Stress Measurement
Authors: Holt R. A. 
Published: March 2019

Recent developments in position sensitive detectors (PSD's), solid state power and computer technologies make it possible to design accurate instruments for in-situ stress measurement. Such instruments require compromises in the interests of portability, size and speed stiich may limit accuracy and/or versatility. Furthermore, extraction of a stress tensor from X-ray data is not always straightforward and considerable research is required before an instrument for X-ray stress measurement can be treated as a “black box” to be given to an uneducated operator.The development of a new instrument for in-situ stress measurement is described in this paper. It was conceived as a field instrument with two position-sensitive proportional counters (PSPC's) for use in the single exposure mode (SET), and incorporates precise angular qontrol of the incident X-ray beam and data analysis to eliminate irregular Bragg peaks owing to coarse grain structure, An experimental instrument was built tc test the concept (1).
The Use of Person VII Distribution Functions in X-Ray Diffraction Residual Stress Measurement
Authors: Prevey Paul S. 
Published: March 2019

AbstractThe fitting of a parabola by least squares regression to the upper portion of diffraction peaks is commonly used for determining lattice spacing in residual stress measurement. When Kα techniques are employed, the presence of the Kα doublet is shown to lead to significant potential error and non- linearities in lattice spacing as a function of Sin2ψ caused by variation in the degree of blending of the doublet. An algorithm is described for fitting Pearson VII distribution functions to determine the position of the Kα component, eliminating errors caused by defocusing of diffraction peaks of intermediate breadth. The method is applied to determine the subsurface residual stress distribution in ground TI-6 AI- 4 V, comparing directly the use of parabolic and Pearson VII peak profiles, and is shown to provide precision better than ± 1%% in elastic constant determination.
Rapid Composition-Depth With X-Ray Diffraction: Theory and Practice
Authors: Wiedemann Karl E. , Unnam Jalaiah 
Published: March 2019

AbstractHigh precision composition-depth profiles can be determined quickly using a recent development. This method requires that noncompositional broadening arising from the instrument, crystal defects, and the radiation source be removed from the diffraction pattern before calculating the composition-depth profile. Effective deconvolution techniques, profiling theory, methodology of profiling, and the effect of residual noncompositional broadening on the profile are discussed. Examples include statistical analyses of error in the profile due to random counting errors and variance in the lattice parameter calibration.
Quantitative Analysis of thin Samples by X-Ray Diffraction
Authors: Brandt C. G. , van der Vliet G.H. 
Published: March 2019

For phase analysis of small amounts of material in an x-ray powder diffractometer the sample is often spread on a sample mounting plate or support plate. Different types of plates on which thin samples can be mounted are:- silver membrane filters- metal or other polycrystalline plates- polymer membrane filters, for example PVC, polycarbonate, cellulose nitrate- glass slides- single crystals; cut so that no diffraction lines occur.Filters are often used to collect environmental dust; these samples can be analysed “as received,” Glass slides are inexpensive, flat, and readily available. Polycrystalline filters and plates have the disadvantage of possible line overlap with lines of the sample material (refer to figure 1), Glass plates or polymer filters have the high and curved background due to amorphous scatter as shown in figure 2.
Adjustment of Solid-Solid Phase Transition Temperature of Polyalcohols by the Use of Dopants*
Authors: Chandra D. , Barrett C. S. , Benson D. K. 
Published: March 2019

AbstractThe transition temperatures of solid-solid phase changes in selected polyalcohols, “plastic crystals,” can be adjusted by using interstitial and substitutional dopants. An investigation is under way of the structural changes in these during heating and cooling, and of the thermodynamic properties such as the transition, temperatures and enthalpy changes, as a function of the percent of dopant. The purpose of the investigation is to find and evaluate materials having potential value In thermal storage applications. Dopants for pentaerythritol discussed in this report are trimethylolpropane (TMP), ammonia, boron trifluoride, pentaglycerine (PG) and neopentylglycol (NPG).
Simultaneous Determination of the Lattice Constant and Elastics Strain in Cubic Single Crystal
Authors: Ortner Balder 
Published: March 2019

In epitaxial single crystal growing it happens very often that the composition of the grown film, say AxB1-x C, is not known exactly. Usually it would be possible to find out that compositions imply by determining the lattice constants of the film. The problem of such a measurement lies in the fact of internal and unknown stresses in the film. On the other side the knowledge of the state of stress σ and strain ε can also be of great importance. To calculate the stresses from X- ray measurements we need the lattice constants in the unstrained condition.Hornstra and Bartels have shown that the lattice constant can be det ermined by X-ray measurements if the strain is isotropic in the film plane. In the following we show that the lattice constant and the full strain tensor can be calculated fromat least four X- ray measurements also in the general case.
A Combined Fundamental Alphas/Curve Fitting Algorithm for Routine XRF Sample Analysis
Authors: Kalnicky Dennis J. 
Published: March 2019

AbstractAnalysis of sample composition and/or thickness in a routine, process-control or monitoring environment generally requires rapid turn-around time with minimal sample handling. X-ray Fluorescence (XRF) is well-suited for these kinds of analyses and has been applied to various bulk and thin sample applications (1-7). This technique is rapid, precise, non-destructive, and requires minimal sample handling.X-ray Fluorescence is generally considered a secondary analysis technique, that is, instrumentation must be calibrated using known standards before unknown samples may be analyzed (quantitative analysis). Continuing work on standardless approaches, particularly for Energy-Dispersive XRF (EOXRF) systems, relax this requirement for some samples but the large share of XRF analyses still require calibration with standards. A number of mathematical and non-matheraatical techniques have been devised to calibrate XRF measurements for many different sample types (1,2,8,9).
Comparison of Strategies For Dealing With Unanalyzed Light Elements in Fundamental Parameters X-Ray Fluorescence Analysis
Authors: DeGroot Peter B. 
Published: March 2019

AbstractThe total elemental composition of a sample must be measured or specified for successful application of fundamental parameters type matrix corrections in x-ray fluorescence analyses. Unanalyzed light elements can be dealt with in three ways. They can be related to the concentration of another element by stoichiometry, calculated by difference, or their effects minimized by addition of a diluent of known composition, ‘The relative success of these approaches depends on the composition of the sample. Limiting cases tested are high or low concentrations of analytes having long or short wavelength emission lines, in the presence of additional heavy or light elements. Molybdenum oxide is used as the analyte, with the oxygen serving as a typical unanalyzed light element to be treated by stoichiometry, difference, or dilution. The accuracy and precision of the analysis for molybdenum, using either the Kα or Lα line, is the criterion for judging the success of the strategy. Experimental results and theoretical calculations using the XRF11* matrix correction program are employed. Generally, the difference strategy is inferior to stoichiometry or dilution. However, difference methods can give acceptable results except in the case of a high concentration of short wavelength analyte in a light element matrix. Where stoichiometry is not known, an assumed stoichiometry that is correct within one oxidation number gives results comparable to the difference method.
X-Ray Fluorescence Spectroscopy as a Technique for Studying Surface Concentration Profiles of Heterogeneous Catalysts
Authors: Kenny Eva M. , Palmer Burton J. 
Published: March 2019

AbstractX-ray fluorescence spectroscopy is usually not considered a surface technique in the same sense as ESCA or Auger spectroscopies. However, it can be a useful tool in studying the “surface” and bulk concentrations of elements in heterogeneous catalysts. The “surface” is defined by the effective penetration depth of the analyte line of the element of interest in a specific matrix. In the example which is presented, silver on alumina, the “surface” using the Ag KB1,3 is defined by a shell 3000 microns deep while for the Ag LAI it is 15 microns. Two methods of sample preparation are discussed and data obtained using three different calculation methods is presented. Data from the x-ray fluorescence method is compared to the silver depth profile in the alumina pellets obtained by electron microprobe analysis. The XRFS method allows rapid screening of many catalyst samples for the fraction of the cost of the microprobe technique.
Small X-Ray Tubes for Energy Dispersive Analysis Using Semiconductor Spectrometers
Authors: Jaklevic J. M. , Giauque R. D. , Malone D. F. , Searles W. L. 
Published: March 2019

Fast X-ray fluorescence analysis with radioisotope excitation requires intense sources to produce reasonable counting rates. The inconvenience of handling such sources and the small number of suitable radioisotopes places severe limitations on their use.We have explored the possibility of using low-power X-ray tubes as exciting sources for energy-dispersive fluorescence analysis. The principal advantage to X-ray tubes is the ability to produce X-ray fluxes to three orders of magnitude higher than those obtained with convenient radioisotope sources while dissipating only a few watts in the tube. Furthermore, the variety of possible anode materials and range of currents in the tube make possible optimum choice of exciting energy and intensity for particular applications.We have designed and tested such tubes in a variety of anode configurations suitable for fluorescence excitation. Using either X-ray filtering techniques or multiple fluorescence geometries It is possible to significantly reduce the Bremsstrahlung background relative to characteristic radiation.As compared with normal radioisotope-target assemblies, excitation of a sample by the X-ray tube results in comparable sensitivity in only a tenth to one hundredth of the time.
Old Errors and New Corrections in X-Ray Line Profile Analysis
Authors: Kidron A. , Angelis R.J. De 
Published: March 2019

In recent years there has been an increasing awareness of the errors involved in X-Ray line profile analysis which is used to calculate coherently diffracting particle size, local strains and stacking fault probabilities in materials. Here a modified version of a Least Squares Analysis (L.S.A.) of the Fourier coefficients is presented. This method gives a possibility of making new corrections in a more natural and accurate way to the errors in the line profile analysis.The first error involves the fact that experimentally one accumulates data as a function of θ - the Bragg angle, whereas the Fourier analysis is made in terms of equidistant steps in sin θ, In the L.S.A. the data does not have to be given in equidistant steps of sin θ in order to be analyzed, so that this type of error does not exist at all.In the L.S.A. there is also no need for the explicit separation of the Kαl component from the total doublet line profile. This type of analysis is taken here one step further and it is shown that one can calculate the Fourier coefficients of each one of two merging lines. Each of these lines may be doublets in themselves and the two series of Fourier coefficients are calculated around the centers of gravity of their Kαl components respectively.The existence of an extra background which usually affects the Fourier coefficients when calculated by the Fourier transform method does not affect the L.S.A. except for a normalization factor. Here it is shown that this gives the possibility of calculating the strains without errors associated with the extra background.