bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of Structural Detail by X-rays of Wavelength Greater than 4Å
Authors: Herglotz H. K.
Published: March 2019

Some branches of structural research could benefit from supplemental information provided by “soft” x-rays. Little use is made of these wavelengths because they are difficult to generate at high intensity, hard to collimate, need vacuum for propagation, and are heavily absorbed in the sample. None of these difficulties is insurmountable, however, and it will be shown that the information to be gained is often worth the extra effort.

A few theoretical and experimental examples with silver L-radiation (λ ≈ 4.15Å) and aluminum K-radiation (λ ≈ 8.34Å) demonstrate that valuable semiquantitative information on the size and number of aperiodic scatterers in solid samples can be extracted. Other examples show the superior sensitivity of these longer wavelengths to dimensional changes in periodic lattices. Applicability of long-wavelength diffraction is restricted to values of interplanar distance d > λ/2. Valuable information about lattice imperfection can be gained from broadening of the reflection at larger glancing angles. It is shown that the heavy absorption of these wavelengths in the sample is not necessarily prohibitive.

The instrumentation used in these studies was designed for routine operation by laboratory personnel without special training. It consists of a demountable high-intensity x-ray source and a multipurpose highvacuum camera. Operation of the x-ray unit resembles that of commercial x-ray diffraction instruments. Because of its greater-flexibility, photographic recording has been practiced so far but could be replaced by electronic readout.
X-ray Astronomy Laboratory at the University of Chicago
Authors: Blake R. L. , Passin T.
Published: March 2019

A laboratory has been established with two primary objectives. First it is to permit test and calibration of rocket and satellite x-ray astronomy experiments. Second it is for studies in ultrasoft x-ray physics. The basic units described are a precision x-ray spectrometer, a separate precision spectrograph, direct and fluorescence excitation sources, the rocket payload test chamber, and auxiliary components. Planned applications include measurements of crystal reflection coefficients, rocking curves, light element absorption edge structure, and spectroscopy of solid and high temperature gas sources.
The Application of X-ray Line Broadening to a Study of Substructure Strengthening in Dispersion Strengthened Alloys
Authors: Clegg M. A. , Lund J. A.
Published: March 2019

A refined x-ray line profile analysis was used to determine the lattice strain distribution and crystallite domain size in nickel and a series of alloys, Ni-Cr, Ni-ThO2 and Ni-Cr-ThO2 in a wide range of thermo-mechanical conditions. Corrections were made for instrumental broadening and doublet broadening according to Stokes and Rachinger respectively, for errors due to the “hook effect”, for terminal errors in the series arising from Instability of the components, and for the presence of stacking faults and twins on the basis of peak shift and asymmetry. The internal consistency of the x-ray data was reviewed critically and good agreement was found. The values of lattice strain and domain size were used to evaluate the presence of a dislocation substructure and the degree of polygonization of the subgraln boundaries.

It was concluded that the thoria-free materials developed much higher lattice strains during cold rolling than did the Ni-ThO2, due it is thought to the operation of multiple slip in the latter. The Ni-Cr-ThO2 also developed high lattice strains during cold rolling, similar to those of the thoria-free lattices, and this was explained by the influence of chromium on cross-slip. It was postulated that the regions of high lattice strain act as driving forces in the process of recrystallization and promote grain growth during heat treatment following cold rolling.

The x-ray results were correlated with transmission electron microscopy and tensile data in a parallel study in which models for room temperature and high temperature strengthening were proposed.
Applications of Rietveld Analysis to Materials Characterization in Solid-State Chemistry, Physics and Mineralogy
Authors: Hill R.J.
Published: March 2019

The utilization and optimization of the properties of materials follows most effectively from a detailed knowledge and understanding of the positions and energetics of their constituent atoms, generally obtained from scattering/diffraction experiments involving electrons, neutrons or electromagnetic radiation. For the most part, these experiments are undertaken on individual crystals of the material, thereby preserving the resolution (and information content) of the three-dimensional reciprocal lattice. However, many of the substances of greatest academic and technical importance either do not crystallize with dimensions large enough for single-crystal studies, or display the properties of maximal interest only when present in finely-divided (powdered) form. In a diffraction experiment, the reciprocal lattice is then collapsed on to the single dimension of the 2θ scale.
Size-Strain and Quantitative Phase Analysis by the Rietveld Method
Authors: Scardi Paolo , Lutterotti Luca , Di Maggio Rosa
Published: March 2019

A modified version of the Rietveld method has been developed for quantitative phase analysis in conjunction with crystallite size and microstrain determination.

Besides the information on the microstructural disorder in the different phases present in the sample, accurate phase analysis can be performed, even in presence of anisotropic crystallites, taking into account the non-instrumental peak broadening effect in a better way compared to conventional methods.

The method has been tested on binary mixtures of corundum, ceria stabilized zirconia and on a polyphase stabilized zirconia sample.
High Resolution X-Ray Powder Diffraction by the Combination of Synchrotron Radiation and Imaging Plate to Observe Electron Distribution by the Maximum Entropy Method
Authors: Takata Masaki , Yamada Manabu , Kubota Yoshiki , Sakata Makoto
Published: March 2019

A Debye-Scherrer camera (radius 572 mm) was designed for the use at the Photon Factory BL-6A2. It uses 4 pieces of the Imaging Plate to cover 0° ∼ 160° in 2θ. The profiles measured by the camera had 0.083° full width at half maximum (FWHM) and were rather symmetric compared with conventional X-ray source. The observed profiles were well represented by either the split Pearson VII or pseudo-Voigt function. In order to examine the performance of the new camera, the whole powder data of LiF was analyzed by the Maximum Entropy Method(MEM). The MEM analysis of LiF was successfully accomplished using 20 measured structure factors and gave R(Bragg) 0.25%. The density distribution obtained represented a characteristic feature of ionic crystals and was consistent with the theoretical result of the self-consistent LCAO method.
Characterization of Single- and Multiple-Layer Films by X-Ray Reflectometry
Authors: Huang T. C. , Parrish W.
Published: March 2019

Precision X-ray reflectivity data were obtained with a high-resolution reflectometer equipped with a rotating anode X-ray source and Ge 220 channel monochromators (one placed before and the other after the specimen). The surfaces and buried interfaces of thin films were characterized by ieast-squares refinement of experimental data. Values of thickness, density, and/or roughness of Pt “single-layer” and Pt/Co based multiple-layer films were determined.
Depth Profiling of Ceramic Specimens using Multi-Wavelength X-Ray Bragg-Brentano Diffraction Data with Particular Reference to Zirconia-Aluminas
Authors: van Riessen A. , O'Connor B.H.
Published: March 2019

Depth profile analysis of phase composition, residual strain and crystallite size in ceramic specimens can be determined by varying the information depth (ID) as defined by Delhez et al. (1988) for an x-ray opaque specimen. The information depth may be controlled by making use of the dependence of ID on Bragg angle and by selecting wavelengths which give appropriate x-ray absorption within the specimen.

Procedures are outlined for extracting depth profiles for (i) composition from intensity data and (ii) residual strain and crystallite size from peak width data. Results are described for both discrete-peak and Rietvetd pattern-fitting analysis of zirconiaalumina specimens for which preliminary results have been reported by van Riessen et al. (1990).
Texture Analysis of Bulk Samples by Neutron Diffraction Using a Position Sensitive Detector
Authors: Will G. , Jansen E. , Schäfer W.
Published: March 2019

Texture (of a polycrystalline sample) means the orientation distribution of the many crystallites in the sample with respect to a coordinate system on the sample, for example the rolling direction. Texture is responsible for many macroscopic properties of materials, for example in metals and alloys in the process of rolling or hot-pressing. It carries importance in many everyday production processes. Also in areas of geological science the texture of the sample, e.g. of the rocks should be known in order to explain geological processes.
XRD Instrument Sensitivity Results from a Round Robin Study
Authors: Schreiner W.N. , Jenkins R. , Dismore P.F.
Published: March 2019

During the course of the past ten years the International Centre for Diffraction Data has sponsored a number of “Round Robin” tests to evaluate the quality of experimental X-ray diffraction data [1-5]. The latest of this series, called the Instrument Parameter Round Robin, was designed to evaluate, among other things, relative angularly-dependent sensitivity differences between diffractometers. Previous experiments have indicated that even perfectly aligned diffractometers of the same generic type, do not necessarily give the same set of relative intensities. One objective of the round robin was to quantify the magnitude of the experimental differences between data sets, and to demonstrate a means for external calibration of diffractometers, so that digitized diffraction intensity data obtained from different instruments could be directly compared.
A Low Cost Secondary Two Theta Standard for Powder Diffractometry
Authors: Stabb David J.
Published: March 2019

Silicon powder, available as a Standard Reference Material, fulfills most of the requirements for a two theta standard. However, It has no diffraction lines at the low 2θ values characteristic of some species. Standard synthetic mica is available but expensive.

Experiments with a commercially available high silica zeolite have shown that it is a valuable secondary standard. It is non-toxic, stable, inexpensive and possesses a large (24 Å) unit cell. Peaks show clearly from 14 Å (6°2θ for Cu Kα).

An example is given of the use of this secondary standard in determining lattice parameters.
Formalism for the Evaluation of Pseudo-Macro Stress Fields σ33(z) from Q-AND ψ-Mode Diffraction Experiments Performed with Synchrotron Radiation
Authors: Ruppersberg H.
Published: March 2019

A self-consistent scheme is proposed for the evaluation of stressfields which vary strongly within the penetration depth of the X-rays in polycrystalline specimens which are elastically isotropic and homogeneous on a macroscopic scale. Very precise diffraction experiments have to be performed for practical applications.
Material Strength Evaluation and Damage Detection by X-Ray Diffraction
Authors: Goto Toru
Published: March 2019

The number of products that have to be inspected in pre-service and/or in service is increasing. Not only inspection for flaws are required increasingly, using the ordinary non-destructive testing, but also inspection of material characteristics, such as material strength evaluation and/or damage detection. For such inspection, X-ray diffraction has great possibilities as one of the most promising techniques, because it is (a) noncontact, (b) very sensitive to changes in parameters of the crystalline structure, and (c) suitable for surface observation.

In this paper, three topics are introduced which will be useful in the field of material strength evaluation and damage detection using X-ray diffraction.
X-Ray Analysis of Stress in a Localized Area by Use of Imaging Plate
Authors: Yoshioka Yasuo , Ohya Shin'ichi
Published: March 2019

For determination of stress in a localized area, we combined a modified single exposure technique and the imaging plate, which is an x-ray digital area detector. With the, single exposure method, stress value is obtained from lattice strains in two directions with a single incident x-ray beam directed at an oblique angle. However, since diffraction data around a whole Debye-Scherrer ring was used in this study, a stress value can be accurately determined in comparison with the single exposure method. We observed the DS ring by use of the imaging plate with requiring only a short exposure time. Lattice strains in many directions on a DS ring were measured by an image analyzer connected to a computer; we verified the effectiveness of this method.
Saxs Measurement of Morphology and its Relationship to Melting Point Depression in Poly(Beta-Hydroxybutyrate-CO-Beta-Hydroxyvalerate) Random Copolymers
Authors: Bluhm Terry L. , Orts William J. , Marchessault Robert H.
Published: March 2019

Small-angle x-ray scattering (SAXS) and wide-angle x-ray diffraction (WAXD) data are used to establish relationships among the degree of crystallinity, melting temperature and lamellar thickness for random copolymers of poly(β-hydroxybutyrate-co-β-hydroxyvaierate) (PHB/V). The morphology of this isodimorphic system is best described by a two phase model consisting of crystalline and amorphous domains having density fluctuations within each domain. The Sanchez-Eby inclusion model is used to predict melting point depression in these materials and, combined with SAXS data, to gain insight into the degree of inclusion of hydroxy valerate units within the polyhydroxybutyrate crystalline domains.
X-Ray Tubes for Energy Dispersive XRF Spectrometry
Authors: Skillicorn Brian
Published: March 2019

X-ray tubes are used extensively in energy dispersive x-ray spectrometers in preference to radioactive sources because of their high output, variable intensity and tuneable energy spectrum. Tubes for this application have certain requirements which make them different in detail from the more common radiographic or therapy tubes and this paper sets out to present a review of some of the fundamental features of modern spectrometry grade tubes.
Examples of Analysis from an Integrated X-Ray Fluorescence Analysis System Using NRLXRF
Authors: Artz B. E. , Rokosz M. J.
Published: March 2019

Methods of correction for matrix differences are required in X-ray Fluorescence (XRF) Analysis when the overall composition of the unknowns is substantially different from the available standards. Sample preparation techniques used to minimize matrix differences often require development time and can consume irreplaceable sample material. Alternatively, the increasing computer power available to the analyst and the refinement of computer programs using fundamental parameter calculations has made this approach more attractive.

A system-consisting of a Siemens SRS-1 wavelength dispersive spectrometer (WDS), a KEVEX 0810-A/NS880 energy dispersive spectrometer (EDS), software for data collection and manipulation and a 40 element version of the NRLXRF fundamental-parameters analysis program has been put together to simplify XRF analysis of samples lacking standards of a similar composition. This configuration is shown schematically in Figure I.
The X-Ray Analysis of Uranium Ores for Iron Sulfide Minerals
Authors: Durbetaki A. J. , Carlson R. H. , Quail T. F.
Published: March 2019

Hydrogen peroxide is used to extract uranium by the in situ leaching of sandstone ore deposits containing uraninite (UO2). Since FeS2 minerals, marcasite and pyrite, also occur in these deposits and they consume hydrogen peroxide in their oxidation, it is important to determine their concentration.

A quantitative X-ray diffraction (XRD) method was therefore developed in order to monitor the concentration of marcasite and pyrite in sandstone ores.
Quantitative Determination of Ga, Zn, Cu, Hi, Mn, and Cr by X-Ray Fluorescence in Laterites and Bauxites Using Two Evaluation Methods
Authors: Schorin Hasso
Published: March 2019

Laterites and bauxites are residual products derived from a wide variety of rocks by intensive chemical weathering under strongly oxidizing and leaching conditions. Generally the main constituents of these residues are Fe, Al and Ti present in form of hydroxides and/or oxides. The content of silica depends on the thoroughness of the leaching process. The behaviour of trace and minor elements as Ga, Zn, Cu, Ni, Mn and Cr during the laterite/bauxite formation is not yet well established. Precise and accurate analyses of these elements are a prerequisite for such investigations. In this paper the standard addition method is presented and the results are compared with those obtained by calibration standardization. The accuracy and the precision of the methods as well as the distinction limit and the limit of detection for each element are given.
Energy Dispersive XRF Analysis of Lubricating Oil Additives with Secondary Target Excitation and the EXACT Fundamental Parameters Program
Authors: Stehr Kenneth C.
Published: March 2019

The need for rapid and accurate analysis of lubricating oil additives is firmly established by the petroleum industry. The application of energy dispersive X-ray fluorescence spectrometry techniques to this analysis is a valuable aid in achieving reliable and fast quality control of these product types.

Due to the large concentration variations possible for the elements of interest within these materials (principally Zn, Ca, P, S at 0-20%), interelement effects can become significant. In order to correct for interelement effects, historical XRF methods have relied on a large number of standards for each element to be determined or matrix matching with standards closely bracketing the unknown sample concentrations.
The Measurement of Low Concentrations of Organic and Inorganic Gaseous Contaminants in Occupational Environments by X-Ray Spectrometry (XRS)
Authors: West N. G. , Purnell C. J. , Brown R. H. , Withers E.
Published: March 2019

To ensure that workers in certain industries are not exposed to harmful levels of toxic chemicals, it is necessary to provide regular monitoring of the concentrations of chemical contaminants in the workplace air. In the United Kingdom, monitoring is normally carried out on a routine basis by the factory occupier backed up by periodic visits from the Factory Inspectorate acting on behalf of the Government. The main source of guidance for occupational hygienists in assessing conditions in a factory is the list of threshold limit values (TLVs) published annually by the American Conference of Governmental Industrial Hygienists. Threshold limit values refer to airborne concentrations of substances and represent conditions under which it is believed that nearly all workers may be repeatedly exposed day after day without adverse effect.
X-Ray Diffraction Quantitative Analysis Using Intensity Ratios and External Standards
Authors: Goehner Raymond P.
Published: March 2019

The use of quantitative x-ray diffraction (XRD) as an analytical technique has recently become increasingly popular. There ate primarily two reasons for this increasing interest in a relatively old discipline. The first is simply the need for quantitative phase analysis. This need arises from several sources such as government regulations on respiratory quartz, industrial quality control, and material research. X-ray diffraction provides a readily available technique for bulk phase analysis on chemically similiar phases. For phases which are elementally distinct, our sister science, x-ray fluorescence, can more easily provide the quantitation needed. The second reason for the increasing interest in quantitative XRD is the ready availability of automated powder diffractometers. These instruments remove much of the tedium involved in the collection and reduction of the data.
X-Ray Residual Stress Mapping in Industrial Materials By Energy Dispersive Diffractometry
Authors: Bechtoldt C. J. , Placious R. C. , Boettinger W. J. , Kuriyama M.
Published: March 2019

An application of energy dispersive diffractometry to the measurement of residual strains (stresses) in the interior of industrial materials is described with particular emphasis on the use of high energy (up to 250 keV) x-ray photons. The use of high energy photons permits better penetration into materials. Hence diffraction data for evaluating bulk residual strains can be obtained in the transmission geometry in contrast with the conventional angular dispersive diffractometry, which uses Bragg reflections from the surface of materials. The reliability and sensitivity (detectability of small strains) of the energy dispersive method are demonstrated through its application to mapping of residual stress distributions across weld zones in Alaskan pipe line segments (API5LX65). The detectability of strain variations within materials depends on x-ray optical resolution and statistics.
Estimation of Ahisotropy of X-Ray Elastic Modulus in Steel Sheets
Authors: Nagashima Shin-ichi , Shiratori Masaki , Nakagawa Ryuichi
Published: March 2019

The oscillation from a linear relation in the 20 vs. sin2ψ diagram has been a most important problem in X-ray stress measurement. There are, therefore, a number of papers concerned with the X-ray elastic constant, lattice strains under stresses and evaluation of stresses of textured materials.

The purpose of the present study is to analyze the three-dimensional orientation distribution of steel sheets by means of the Vector method proposed by Ruer and Baro, and to calculate the elastic modulus of textured sheets by means of a finite element method (FEM) using the three-dimensional orientation distribution, and then to calculate the strain/stress ratios vs. the directions defined by the angles between the specimen normal and the normal to the diffracting planes.
X-Ray Fractography On Fatigue Fracture Surfaces of Aisi 4340 Steel*
Authors: Hirose Yukio , Yajima Zenjlro , Mura Toshio
Published: March 2019

The X-ray fractographic technique was applied to fatigue fracture surfaces of tempered AISI 4340 steel. Residual stresses and half-value breadths were measured by the X-ray diffraction.

In the present paper, the residual stresses and plastic strains on fatigue fracture surfaces and some parameters in the fracture mechanics were investigated. A simple model of mechanics was proposed to explain these experimental results.
Special Application of the Debye Microdiffractometer
Authors: Steinmeyer P. A.
Published: March 2019

The Debye microdiffractometer, a recently developed instrument, enables diffraction patterns to be obtained from very small samples or from selected areas of samples. The instrument discussed here, a Rigaku Model 2870E1 microdiffractometer, features an annular sealed proportional counter which is moved along the primary beam axis for two theta scanning, as seen in Figure 1, This configuration allows most of a Debye cone to be detected, making the use of a primary bean typically less than 100 microns in diameter practical. An integral microscope facilitates sample positioning for diffraction from selected areas of a specimen. The capability of the Instrument is apparent from the diffractometer traces of Figure 2, in which intermetallie compounds in a braze joint are identified.
Application of Synchrotron Radiation Excited X-Ray Fluorescence Analysis to Micro and Trace Element Determination
Authors: lida Atsuo , Gohshi Yohichi , Maezawa Hideki
Published: March 2019

Micro and trace element analysis by X-ray fluorescence was carried out using synchrotron radiation from a bending magnet and an undulator for hard and soft X-ray excitation respectively. The minimum detection limits obtained in the hard X-ray region were less than pg, which corresponds to a spatial resolution of less than a hundred micronmeters, with a detection limit of a few ppm. Light elements such as oxygen, nitrogen and carbon in silicon compounds were analyzed by soft X-ray emission spectroscopy using undulator radiation. The minimum detectable amount of the light elements was greatly improved, since undulator radiation is very strong in intensity, and is highly collimated.
A New Method for Orientation Distribution Function Analysis
Authors: Matsuo Munetsugu , Kawasaki Koichi , Sugai Tetsuya
Published: March 2019

As a means for quantitative texture analysis, the crystallite orientation distribution function analysis has an important drawback: to bring ghosts as a consequence of the presence of a non-trivial kernel which consists of the spherical harmonics of odd order terms. In the spherical hamonic analysis, ghosts occur in the particular orientations by symmetry operation from the real orientation in accordance with the symmetry of the harmonics of even orders. For recovery of the odd order harmonics, the 9th-order generalized spherical harmonics are linearly combined and added to the orientation distribution function reconstructed from pole figures to a composite function. The coefficients of the linear combination are optimized to minimize the sum of negative values in the composite function. Reproducibility was simulated by using artificial pole figures of single or multiple component textures. Elimination of the ghosts is accompanied by increase in the height of real peak in the composite function of a single preferred orientation. Relative fractions of both major and minor textural components are reproduced with satisfactory fidelity In the simulation for analysis of multi-component textures.
X-Ray Fluorescence Analysis of Wear Metals in Used Lubricating Oils*
Authors: Maddox William E. , Kelliher Warren G.
Published: March 2019

Analyses of lubricating oils from aircraft engines, gear boxes and other lubricated mechanisms have been routinely performed by the military since the 1960's. The monitoring of the wear metal concentrations in the oil can lead to an early detection of abnormal wear and, consequently, the prevention of a malfunction or a complete failure of the aircraft. At the present time, almost all the analysis programs use atomic emission (AES) and/or atomic absorption (AAS) spectroscopy to determine elemental concentrations in the oils (1). These types of analysis require the close support of a laboratory to minimize the delays in obtaining the results of the measurements. The AES and AAS methods are very inefficient for particles 3 - 6 μm in size and are essentially blind to particles larger than 6 - 10 μm (2,3).
The Application of High-Resolution Solid State Detectors to X-Ray Spectrometry - A Review
Authors: Heath R. L.
Published: March 2019

Developments during the past few years in solid-state radiation detectors and low-noise electronics employing field-effect transistors operated at cryogenic temperatures have resulted in the availability of high-resolution energy-dispersive spectrometers for a variety of applications in x-ray spectrometry. Using pulseamplitude analysis techniques, these spectrometers make it possible to obtain multi-elemental analyses on a routine laboratory basis employing x-ray fluorescence techniques. The combination of these spectrometers with small, inexpensive on-line computer data systems makes It possible to obtain rapid on-line qualitative and quantitative analysis of samples in the laboratory and in special field applications. A general review of the present state of development in detectors, electronics and on-line data systems will be presented together with descriptions of applications of such equipment in the laboratory.
On the Method of Variable Take-Off Angle for Quantitative X-Ray Fluorescence Analysis (XRFA)
Authors: Ebel H. , Ebel M. F.
Published: March 2019

Two years ago a paper on a new method of X-ray fluorescence analysis was presented. This method uses a variable take-off geometry and permits a quantitative analysis without calibration curves or the knowledge of the primary X-ray spectrum. As references either chemically analysed samples or pure elements are used. In case that only primary excitation exists, under the aspect, mentioned above, the method is to be regarded as “absolute”. For secondary excitation a simple parabolic approximation has been introduced, which requires a calibration. This paper gives an outline on the progress obtained during the last two years.
Rapid Analysis of Mn Plain Carbon Steels by Nondispersive X-Ray Fluorescence Spectroscopy
Authors: Gehrke R. J. , Cole M. S. , Ryder W. A.
Published: March 2019

Plain carbon steels are primarily composed of iron (~97%), but generally have small quantities of carbon, manganese, sulfur, phosphorous and silicon also present. Lead or copper may also be present. The steel industry is in need of an on-line technique of analysis for manganese in these steels. The manganese concentration of these steels varies from 0.3 to 1.5%. A technique is presented for the rapid analysis of manganese in carbon steels using energy dispersive x-ray fluorescence spectroscopy. It is capable of determining the manganese content of a carbon steel in. less than 30 sec with an uncertainty of less than 0.05% manganese. Because this method can analyze a steel from a distance of two feet, it should be possible to adequately protect the x-ray fluorescence spectrometer from the environment even when analyses are made of hot steel ingots at temperatures ranging up to 2400°F.
An Electro-Optical X-Ray Diffraction System for Grain Boundary Migration Measurements at Temperature
Authors: Green Robert E.
Published: March 2019

Considerable work has been undertaken in order to gain an understanding of the mechanisms responsible for the generation of recrystallization textures developed upon annealing of cold-worked metals. Most direct measurements have consisted of measuring the increase in average diameter of the largest grain growing into a polycrystalline aggregate. Experimental measurements of individual boundaries migrating into deformed single crystals, though of a more fundamental nature, have been made by far fewer investigators. This is probably due to the increased experimental difficulties associated with careful control of such experiments. Most previous investigators have made grain boundary migration measurements by the heat-cool-etch method, despite the fact that it has several marked disadvantages. Other investigators have constructed an X-ray goniometer furnace and used it to measure grain boundary migration rates while the test specimen was maintained at temperature. Since there have been no published reports of the use of such a system in the past thirteen years, it must be concluded that the technique was unsuccessful in general.

The system described in the present work is relatively simple in design and extremely simple to use. Not only does it permit absolute measurement of grain boundary position at temperature but it also permits boundary migration measurements to be made of extremely fast moving boundaries. The basic components of the system are as follows. A continuous spectrum X-ray beam is converted by a slit collimating system into a beam which is incident along the entire length of the test specimen. This beam is interrupted by a wire grid just prior to impingement on the test specimen. The test specimen is supported vertically in a furnace maintained at the temperature required for grain boundary migration. The various diffracted X-ray beams pass out of the furnace through a highly reflecting insulating baffle made from very thin aluminum foil and impinge on a fluorescent screen. This screen converts the X-ray image into a visible one which is amplified and recorded using the electro-optical system.
Detector Background And Sensitivity Of Semiconductor X-Ray Fluorescence Spectrometers
Authors: Goulding F. S. , Jaklevic J. M. , Jarrett B. V. , Landis D. A.
Published: March 2019

Degraded detector pulses are shown to contribute most of the background in spectra produced by semiconductor-detector X-ray spectrometers. A new guard-ring detector is used with appropriate circuits to reduce background by a large factor. We discuss the sensitivity of the new arrangement with various excitation sources.
An Improved X-Ray Fluorescence Method for the Analysis of Museum Objects
Authors: Salmon Maurice E.
Published: March 2019

A method is described for the x-ray fluorescence analysis of small samples, taken from museum objects, to determine alloy composition. The samples are dissolved in an appropriate reagent and absorbed on cellulose powder. The resulting powder is formed into a film of less than critical thickness and the effective absorption of the sample for the characteristic wavelength of the element being measured is determined. The effective absorption coefficient is used to correct the observed intensities in order to obtain quantitative results.
Automated lattice Parameter Determination on Single Crystals
Authors: Segmuller Armin
Published: March 2019

A commercial powder diffractometer linked to an IBM 1800 time sharing computer is used for the precision determination of lattice parameters on single crystals with Bond's method of measuring the angle between two diffracting positions of the crystal, symmetric to the incident x—ray beam. A remote x-ray tube and collimator allows a high angle Bragg reflection to be measured easily in these two positions with only one detector. After scanning the two diffraction line profiles, the peak positions and the lattice parameter are determined on line by the computer. Several methods for determining the peak position are discussed. Using these techniques, the lattice parameter of silicon has been determined on two crystals of high purity and perfection to a0 = 5.43093 ± 0.00002 Å and a0 = 5.43095 ± 0.00002 Å at 25°C. These values are in excellent agreement with Bond's result, a0 = 5.430935 ± 0.000019 Å, and they differ slightly from the value a0 = 5.43074 ± 0.00017 Å, the mean value of, lattice parameters measured on silicon powder in 16 laboratories under the I.U.Cr. precision lattice parameter project.
X-Ray Diffraction from Vibrating Quartz Plates
Authors: Spencer W. J. , Pearman G. T.
Published: March 2019

X-ray diffraction topographs of modes in rectangular AT-cut quartz plates are shown. The change in the resulting patterns when different Bragg planes are used is demonstrated. Diffracted x -ray intensity was measured as a function of strain in a vibrating quartz plate . The Lame solutions for quartz plates are briefly described and some experiments suggested for x -ray topography. Finally modes in quartz plates with multiple electrodes are shown indicating the complexity of this type of vibration problem.
An Approach to the Solid Solution Problem Using a Computerized Identification Technique
Authors: Johnson Gerald G. , Chan Frank L.
Published: March 2019

Since for most real systems, solid solution effects influence the position and intensity of the x-ray powder diffraction pattern, it is desirable and necessary to have an automatic system which will identify standard reference phases regardless of the amount of solid solution. Using the system CdS-ZnS, where the lattice parameter a0 changes from 4.136 to 3.820Å, with complete solid solution over the entire range of composition, an illustrative study was made. This work presents the results obtained from a computer analysis of the powder pattern obtained. It has been found that if the starting chemistry is known and the end members of the series are in the ASTM Powder Diffraction File, that the solid solution can be identified. Once the phases present are identified, a plot following Vegard's law yields the approximate composition of the sample under consideration. These two methods of compositional determination agree quite well. Examples of the computer system and description of the program input and output with interpretation of the results will be discussed.
Measurement of the Molecular Size of a Soum Humate Fraction
Authors: Wershaw R. L. , Heller S. J. , Pinckney D. J.
Published: March 2019

Many of the chemical and physical interactions that take place in natural soil-water systems are strongly influenced by the presence of natural organic polyelectrolytes. The most common of these organic polyelectrolytes is humic acid, which is defined as the alkali soluble, acid insoluble fraction of soil organic matter. Over a hundred years of experimental data have demonstrated that a wide variety of different materials having different physical and chemical properties fit this definition. If we are to make any progress in understanding the role of humic materials in soil-water systems, then we must have a classification system which, as far as possible, provides a unique taxonomic definition for each separate molecular species that falls into the category of humic acid.
Quantitative Matching of Powder Diffraction Patterns
Authors: Frevel L. K.
Published: March 2019

An updated d, I-MATCH procedure [Frevel and Adams, Anal. Chem., 40, 1335-1340 (1968)] is described which permits analysts to compare diverse powder-patterns in a quantitative,objective manner. Criteria are established for rating the quality of a diffraction standard. The d, I-MATCH program has been combined with an efficient SEARCH program to facilitate the quantitative matching of multiphase powder patterns.
Experimental and Calculated Standards For Quantitative Analysis by Powder Diffraction
Authors: Hubbard C. R. , Smith D. K.
Published: March 2019

Quantitative analysis by x-ray powder diffraction methods has become increasingly important in recent years with the availability of computer-controlled automatic powder diffractometers. All data gathering techniques require suitable reference standards to scale the measured data properly. One means of achieving this scaling is through the reference Intensity ratio which is defined as the intensity ratio of the strongest diffraction maximum of a substance to the strongest maximum of a reference material in a 1:1 mixture “by weight. These ratios may he measured or they may he calculated if the crystal structures of the materials are accurately known.
Location of Diffractometer Profiles in X-ray Stress Analysis
Authors: Kirk D. , Caulfield P. B.
Published: March 2019

The location of x-ray diffractometer line profiles is of fundamental importance in x-ray stress analysis. Objective estimates of the line profile position may be derived from diffractometer measurements at a number of equally-spaced points in the region of maximum intensity. These estimates are generally based upon the corresponding turning-point of a polynomial fitted to step-scanning data. Techniques are described which simplify the computation involved. A least-squares fitting of a quadratic is satisfactory for most routine applications provided that a reasonable number of points is involved. The three-point parabola method is less satisfactory. Expressions are presented, derived using the maximum-likelihood approach, for peak location and counting variance using both quadratic and cubic equations.
Lama I - A General Fortrah Program for Quantitative X-ray Fluorescence Analysis
Authors: Laguitton Daniel , Mantler Michael
Published: March 2019

A comprehensive Fortran IV program designed to perform the matrix correction in x-ray fluorescence analysis is described. Specimens and standards can be in bulk or film form. All necessary fundamental parameters are provided by internal routines thereby requiring a minimum of input data.
A New Method for the Eliminaion of the Wall Effect in Proportional Counter
Authors: Sipilä K. , Kiuru E.
Published: March 2019

The wall effect present in the gas-filled proportional counters and the low-energy background caused by it are well-known disadvantages. In this paper a method is presented to define the radial position of a single X-ray absorption in ordinary proportional counters. The method utilizes the variation in detector pulse collection times due to the electron diffusion. This variation can be determined with a specially constructed risetime analyzer which effectively forms a dead zone of cylindrical shape inside the detector. The properties and performance of the method are demonstrated. In the experiment performed the signal to background ratio was improved by a factor of twenty.
Precision Lattice Parameter Measurements with Guinier Camera and Counter Diffractometer: Comparison and Reconciliation of Results
Authors: Brown Allan
Published: March 2019

Different procedures used in precision measurements of lattice parameters are, strictly, only valid if they can be shown to give results that are mutually reproducible. For this purpose reproducibility is defined in terms of the parameters a. and standard deviations a. obtained for X-ray specimens of one or more reference materials. The requirement is that all systematic errors should be minimized to a level below that of the random measurement errors. Where these have a Gaussian distribution the significance of the difference, Δa°, between two , measurements can then be Let;Led by evaluating . Thus, if K < 2 the difference, Δa°, cannot be distinguished from the effects of random measurement errors. This condition should be met for specimens of the same sample if reproducibility is good. For K ≥ 3 the value of Δa° is then taken to reflect real differences in the crystalline Jattice of two X-ray specimens of a given compound. A basis is thus created for the study of solid solubility and for the precise characterization of crystalline compounds.
One-Dimensional, Curved, Position-Sensitive Detector for X-Ray Diffractometry
Authors: Sleaford B. , Perez-Mendez V. , Wagner C.N.J.
Published: March 2019

A curved, one-dimensional position-sensitive detector has been designed and constructed for the measurement of the scattering patterns from non-crystalline materials. The chamber is a one-dimensional, pressurized, gas-filled detector with delay line readout for position encoding. It covers an angular range of 45° in 2θ, and its quantum efficiency is 80% and 50% for 17.5 and 60 KeV x-rays, respectively, when using a Xe-20%CO2 gas mixture at 7 atm.
Accurate Geochemical Analysis of Samples of Unknown Composition
Authors: Kikkert J.
Published: March 2019

Considering all fields of analysis by X-ray fluorescence spectrometry geochemical analysis is probably the most complex. The geochemical analyst is often requested to analyse samples of unknown composition and origin. While these samples need to be analysed for a number of elements of economic or geochemical significance it is often impossible or uneconomic to analyse for all elements that could possibly be present in the sample.
XRF Analysis of Vegetation Samples and its Application to Mineral Exploration
Authors: Smith T. K. , Ball T. K.
Published: March 2019

Many analysts use a wet or dry oxidation treatment prior to determination of minor and trace elements in non-fossilised vegetation. This stage is often unnecessary for XRFS since the technique is sufficiently sensitive for many purposes to permit the analysis of unashed material. Indeed, inaccurate results may be obtained if volati1es are lost, if no correction is made for loss on ignition, or if such correction is of large magnitude.
A Fast Algorithm for Fundamental Parameter Calculations
Authors: Pöhn Ch. , Ebel H.
Published: March 2019

A fundamental parameter algorithm for quantitative XFA with characteristic Kα- and Lα-radiations of the specimens is presented. This allows an application to programmable pocket calculators or a fast evaluation of measured countrates for the unknown composition of the specimen by means of PCs. For the practical utilization we need the incidence angle and the takeoff angle of the x-rays in the instrument, the high voltage V in kV which is supplied to the x-ray tube (E0) and reference measurements on either pure elements or a single reference specimen. The quality of the analytical results depends on the concentration differences of the unknown specimen and the reference specimen.
An Algorithm for the Description of White and Characteristic Tube Spectra (11 ≤ Z ≤ 83, 10keV ≤ Eo≤ 50keV)
Authors: Ebel H. , Wiederschwinger H. , Wernisch J. , Pella P.A.
Published: March 2019

Kramers described the cross section of electron interaction with target atoms of atomic number Z by

where Eois the kinetic energy of impinging electrons, and E o S) the energy of x-ray photons of the continuum, Smith et al modified this equation, introducing an exponent x, so that

We applied the cross-section σS, Eto the evaluation of experimental results. The evaluation of the measured spectral responses of the x-ray signals nEwas performed by

where f(deff) describes the absorption of x-rays of energy E in the target, REaccounts for backscattering of electrons, DEquantifies the efficiency of x-ray detection within the solid angle Ω.
Grazing Incidence X-Ray Fluorescence Analysis using Synchrotron Radiation
Authors: Iida Atsuo
Published: March 2019

The X-ray fluorescence analysis of a trace element under a grazing incidence condition has been developed using synchrotron radiation. The interference effect plays an important role for determining the depth distribution of the elemental concentration. The elemental distribution above, on or below the material surface has been studied. The glancing angle dependence of the X-ray fluorescence signal around the critical angle strongly reflects the elemental distribution, and can be used to determine the position of the element of interest.
Grazing Incidence X-Ray Spectroscopy for Thin Layer Analysis
Authors: Hashimoto Hideki , Nishioji Hiroshi , Saisho Hideo
Published: March 2019

Reflection and fluorescence intensity profile curves for thin films were measured under the grazing incidence conditions using synchrotron radiation. A titanium layer and a carbon / titanium bilayer sputtered on a silicon wafer were subjected to heat treatment. The analysis of the reflection and fluorescence profile curves shows that the sample without the heat treatment has another high-density layer on the surface or interface, and that the heat treatment results in the removal of the high-density layer and the formation of a thick homogeneous layer.
The Use of the Conventional Isolated Atom Model for the Theoretical Calculation of the Dependence of Lβ/Lα: Intensity Ratio on the Sample Exit Angle for Unoxidized and Oxidized Transition Metal Alloy Thin Films
Authors: Fujiwara Francis , Andermann George
Published: March 2019

Variable sample exit angle x-ray fluorescence spectroscopy (VEA-XRF) employing the Lβ/Lα intensity ratio for transition metals and their oxides has been shown to be useful for non-destructively studying transition metal surfaces and oxidation, as well as, superconductors. Thus the theoretical formulation of the Lβ/Lα intensity ratio dependence on the sample exit angle, θe, is of some interest and we develop it here. We also present methods of obtaining parameters needed in the formulation, such as Lβ absorption coefficients, which are not available in the literature, for wavelengths greater than about 12Å.
The Comparison of Three Excitation Modes in the Energy Dispersive X-Ray Fluorescence Analysis
Authors: Kanngieβer Birgit , Bockboff Burkhard , Scheer Jens , Swoboda Walter
Published: March 2019

With a new irradiation chamber a comparison of three excitation modes under same conditions and with the same material has been done. The results of this comparison are presented in the following manner: - Barltla scattering (graphite) versus Bragg reflection (HOPS) - Bragg reflection (Mo) versus secondary target fluorescence (Mo) - secondary target fluorescence (Sn) versus Barkla scattering (graphite) Excitation spectra and detection sensitivities of a NBS standard will be discussed for the different modes. The Barkla scattering was found to be the best excitation mode for a wide elemental range.