bluuebunny/crossref_metadata_2025 huggingface dataset:
Use of X-ray Diffraction Using Gaussian Curve Method for Measuring Plastic Strain of Steels
Authors: Kurita Masanori , Chiaki Kenzo
Published: March 2019

Plastic deformation of metals will broaden the x-ray diffraction line. The diffraction line around its peak can he approximated by a Gaussian function. The broadness of the diffraction line can be evaluated by the standard deviation, called Gaussian curve parameter (GCP), of a Gaussian function approximating the diffraction peak. Plastic strains applied to mild steels by simple and combined tension, compression, and tortion were correlated with GCP. Two kinds of GCP's were determined; the one, GCP α', was determined from the diffraction line corrected for the background counts, and the other, GCP α, was from the line uncorrected for the background, The GCP α' can be obtained from the GCP α as

α' = 0.936α + 0.011

This equation shows that the background subtraction can be omitted in determining GCP. The equivalent plastic strain ɛeq can be evaluated from the GCP a as

ɛeq - 0.000108 x 103.97α

This x-ray method allows rapid measurement of complex plastic strain without touching specimens.
Residual Stress Analysis of Silicon Nitride to Carbon Steel Joint
Authors: Kurita Masanori , Kano Takashi , Sato Takashi
Published: March 2019

The residual stress distribution of a ceramic-metal joint specimen was determined by both two- and three-dimensional thermoelastoplastic stress analyses using the finite element method (FEM). The residual stress on the surface of the specimen was also measured by x-ray diffraction. A specimen was prepared by brazing a silicon nitride plate to a carbon steel plate. The highest tensile stress σx perpendicular to the interface appeared at the corners of the silicon nitride adjacent to the interface. The maximum compressive stress σy parallel to the interface occurred at the center of the interface of the silicon nitride. The residual stresses in the silicon nitride and the steel plates distribute antisymmetrically with respect to the center of the specimen. Around the interface, the high stress concentration occurs and the residual stress distributes three-dimensionally, giving a wrong result by the two-dimensional FEM. The residual stress distribution measured by x-rays was similar to that calculated from the three-dimensional FEM.
Reliability of Energy Dispersive X-Ray Fluorescence of Low-Alloy Steels
Authors: Strauss B. H. , Valente F. P.
Published: March 2019

The reliability of energy dispersive x-ray fluorescence data for the analysis of low-alloy steels is reported for chromium, manganese, nickel, and molybdenum. The accuracy and precision of the analysis were evaluated for two mathematical models, linear and multiple regression, using twelve NBS standard reference samples. Data on results are furnished.
Adaptation of the Fundamental Parameters Monte Carlo Simulation to EDXRF Analysis with Secondary Fluorescer X-Ray Machines
Authors: Gardner R. P. , Wielopolski L. , Doster J. M.
Published: March 2019

The Monte Carlo simulation method that has been previously developed and demonstrated for EDXRF analysis with annular radioisotope excitation sources is extended to systems using secondary fluorescer X-ray machines for excitation. Comparisons of the Monte Carlo predictions with experimental results indicate that the modification is valid.
Qualitative Analysis of Complicated Mixtures by Profile Fitting X-Ray Diffractometer Patterns
Authors: Huang T. C. , Parrish William
Published: March 2019

The analysis of mixtures of phases which produce complicated composite x-ray powder patterns is greatly facilitated by use of our profile fitting method and the technique of applying it is illustrated with a five-compound mixture. Profile fitting gave higher precision in the determination of the reflection angles and Intensities and resolved overlaps in a much shorter time than with other methods. If the reference standards are obtained with the same precision, a smaller error window width can b e used in the search/match procedure.
A Versatile Position Sensitive X-Ray Detector
Authors: Steffen D. A. , Ruud C. O.
Published: March 2019

In X-ray diffraction and wavelength dispersive X-ray fluorescence, it is necessary to determine the intensity of a coherently diffracted X-ray peak with respect to its position, two-theta. To accomplish this, most X-ray diffractometers are provided with a scanning goniometer mounted X-ray detector that scans the angular two-theta region of interest and obtains X-ray Intensity as a function of time and therefore two-theta.
Impact of the Personal Computer on X-Ray Analysis Historical Perspective 1960-1990
Authors: Jenkins Ron
Published: March 2019

In these modern times, where the use of the computer in the analytical laboratory is taken for granted, it is perhaps difficult to realize that, less than one generation ago, computers were little more than an idea on an engineer's desk. It is interesting to note the sequence in which the automation of data collection and data processing developed. As would be expected, the time sequence followed closely the developments in computer hardware and peripherals. An important factor in the development of most commercial automated systems was the “20%” rule. This rule required that the total cost of any computer package should not exceed 20% of the sale price of the final automated product. Rex's “Numerical Control Powder Diffractometer” was described in the 1966 Denver Conference and this machine was to be the forerunner of a whole host of automated diffractometers which appeared in the early 1970s. Typical systems used either a 4K minicomputer or a time-sharing system with a large main-frame computer. It is interesting to observe that, as we come into the 1990s, the argument as to whether the main-frame will survive as a viable alternative to the rapidly developing PC still goes on.
Lattice Parameters of Bronze-Type 3BaO·2R2O3·9TiO2 (R=Sm and Nd) Solid Solutions for Microwave Dielectric Ceramics
Authors: Ohsato Hitoshi , Ohhashi Toshiyuki , Sumiya Kazuhiko , Suzuki Shinya , Okuda Takashi
Published: March 2019

Microwave dielectric ceramics with high quality have received attention due to the rapid progress in microwave telecommunication and satellite broadcasting. The desirable properties in microwave dielectric resonators are a high dielectric constant (εr), low dielectric loss (tanδ) (i.e. high Q (Q =1/tanδ)), and low temperature coefficient of the resonant frequency(τf). Properties of dielectric ceramics in the TiO2-rich region of the BaO-Nd2O3-TiO2 ternary system (Fig. 1) were reported to have excellent dielectric constants, low dielectric losses and low temperature coefficients of capacitance by Kolar et al. (1978).
Powder Diffraction Pattern Simulation and Analysis
Authors: Steele James K. , Biederman Ronald R.
Published: March 2019

The graphics capability and speed available in modern personal computers has encouraged an increase in the use of a direct pattern comparison approach to the analysis of x-ray and electron diffraction patterns. Several researchers over the past 30 years have presented programs and algorithms which calculate and display powder patterns for xray diffraction. These programs originally required a main frame computer which was expensive and generally not available to all researchers. With the recent advances in the speed of personal computers, language compilers, and high resoultion graphics, expecially within the past 5 years, real time calculations and display of calculated patterns is becoming widely available. The power of this approach will be demonstrated through the use of an IBM compatable personal computer code developed by the authors.
New Methods for the Accurate Comparison of Lattice Parameters
Authors: Bowen D. K. , Tanner B. K.
Published: March 2019

Two new methods of comparison of lattice parameters are described. The first method uses a double crystal diffractometer, fitted with a specimen rotation stage. Bragg peak positions of a silicon reference and the specimen crystal are recorded for the crystals at 0 and rotated 180° about the diffraction vector. From the mean Bragg positions the lattice parameters can, in principle, be compared to parts in 106. The second method is a variant on the above, using a triple axis diffractometer. It uses a beam conditioner and monochromator to define the incident wavevector ko, and an analyser crystal to define the diffracted wave vector kh. Only the analyser motion must be accurate and stable to the arc second level. We present a detailed error analysis for the case where reference and specimen Bragg angles differ significantly. Peak location to a confidence level of 1 arc second permits absolute, traceable lattice parameter determination to several parts in 106.
High Speed Characterization of Pseudomorphic Hemt Structures Using a Very Low Noise Scintillation Detector
Authors: Loxley N. , Cockerton S. , Tanner B. K.
Published: March 2019

We show that a very low noise, high dynamic range scintillation detector has major advantages over conventional detectors for characterization of pseudomorphic HEMT structures by high resolution X-ray diffraction. We show that the reduced background enables a second modulation period to be detected, enabling the thickness and composition to be determined independently. Using a conventional X-ray generator and diffractometer we demonstrate that, in a single scan taking only 10 seconds, we are able to obtain sufficiently good data to provide quality assurance.
Combined Asymmetric Reflection and Transmission Method for High Accuracy X-Ray Crystallographic Measurements
Authors: Dragoi Danut
Published: March 2019

The work describes a method for determining the orientation of crystallographic planes in thin samples using both asymmetric Bragg reflection and asymmetric Laue transmission method.

The method is based on the extension of a system of nonlinear equations for the reflection case. The solutions of the system of nonlinear equations in question can be positive, negative or mixed with physical significance. The positive solutions correspond to reflection case, while the negative solutions are for transmission case. The mixed solutions were generated for the planes {111} in a cubic structure.

A theoretical test is given for a silicon sample. The results are in good agreement with the experimental results given in literature.
Residual Stress in Thin Films of Aluminum/Hafnium
Authors: Rant S. J. , Goldsmith C. C. , Noyan I. C.
Published: March 2019

Residual stresses in thin films are important technologically due to their impact on the reliability of these structures. Various techniques are used to measure these stresses, and the results of these techniques do not always agree. In some cases, formation of interphase stresses were postulated to account for such discrepancy, but no definitive microstructural analysis was given. In this study, the residual stress response of evaporated films of 9 1% Al - 9% Hf (atomic %) deposited on 0.4 mm thick (100) Si wafers was studied as a function of thermal treatment. The stresses were measured by radius of curvature and d vs. sin2ψ techniques. Concurrently, the microstructure evolution was tracked using powder diffraction and metallographic techniques. As previously reported in the literature, residual stresses were tensile in all cases for both techniques. However, as expected, the stress results from both techniques did not always agree. The delta between the residual stresses measured by the radius of curvature and d vs. sin2ψ techniques were found to correlate well with the development of a 2nd phase (metastable cubic Al3Hf).
Small Area X-Ray Fluorescence Analysis of Multilayer Thin Metal Films
Authors: Zaitz M.A.
Published: March 2019

Thin film technology has become an integral part of semiconductor multichip ceramic packages. Characterizing the thickness of multimetal multilayer thin film structures that combine both thin and thick films is an important parameter for manufacturing process control and development. Accuracies in the range of 3-5% and precisions of 1.3% were attained on multilayer metal films ranging from a few hundred angstroms to tens of thousands of angstroms.
Counting Statistical Errors in Principal Stresses and Directions Determined by Diffraction
Authors: Witte D.A. , Winholtz R.A. , Neal S.P.
Published: March 2019

The state of stress in a material, as represented by the stress tensor, can be measured using x-ray or neutron diffraction techniques. A stress tensor measured using diffraction represents an experimental estimate of the true state of stress in the material. The measured stress tensor will include both instrumental and counting statistical errors. With careful measurement techniques, instrumental errors can be minimized, and accurate results can be obtained. The errors in the measured stress tensor that are due to counting statistics can be estimated using well established error propagation techniques. Unfortunately, these errors cannot be analytically propagated through the solution to the eigenvalue problem which yields the principal stresses and directions. Without estimates of the errors associated with the principal stresses and directions, the values determined for these quantities are of limited value.
New Advantages in Soft X-Ray Stress Measurement and Triaxial Analysis of Nonuniform Stress States
Authors: Wem H. , Suominen L.
Published: March 2019

Conventional stress analysis with diffraction techniques is based on the equations of continuum mechanics, but only few materials encountered in X-ray stress analysis satisfy this assumption. In this paper, a new method is formulated yielding quantitative strain tensor fixed to the specimen coordinates. The method enables independent in-situ determination of Poisson's ratio which serves as a self control mechanism for measurement and evaluation. The analysis has been extended from flat to curved surfaces. Thus an exact analysts of spherical or cylindrical shaped specimens is now possible. The method has the capability to evaluate stress tensor and stress free lattice spacing at the surface as well as their variation with depth. This is demonstrated by two experimental data sets.
X-Ray Diffraction Orientation Studies Using Two-Dimensional Detectors
Authors: Blanton T.N.
Published: March 2019

Two-dimensional detectors utilized in x-ray diffraction studies are described. Film, image intensifier/CCD camera, two-dimensional position-sensitive area, and photostimulable storage phosphor detectors are compared. The storage phosphor detector was found to be well suited for analysis of oriented semicrystalline polyester films. Quantitation of polymer orientation was determined using the Hermans orientation distribution function.
Application of a Flatbed Transparency Scantier as an XRD Scanning Densitometer
Authors: Heuer J. P. , Fernandez J. P. , Lewis R. L. , Cleaver C. G.
Published: March 2019

The days of Debye-Scherrer film as a recording medium for X-ray powder patterns are all but gone with the development of precise, high sensitivity diffractometer systems. However, film does present some advantages over diffractometry (digital positioning and recording) for certain applications, A scanning densitometer system is described which totally automates the analysis of Debye-Scherrer film. It is much more precise and more capable than the simple line readers available in the past and can reduce the analysis time of complicated patterns from hours to minutes.
The Effective Thermal Expansion Of Nickel and Nickel Oxide During High-Temperature Oxidation*
Authors: Wolfi James S. , Cavin O. Burl
Published: March 2019

X-ray diffraction analyses were applied to various pure nickel substrates while exposing them to oxygen at temperatures up to 800 °C. Coefficients of thermal expansion (CTE) were calculated from lattice parameters for both the nickel and the growing surface oxides. Behaviors more complex than the case for single phase bulk solids were observed due, in part, to oxidationinduced strains. The CTE values for such dynamic composite systems are not the same as those for the bulk solids. Thus, for example, the CTE values were found to be dependent on substrate metal thickness. In addition, discontinuities in the CTE's of both nickel and NiO occurred at or near their respective second order phase change temperatures.
The Construction Of Quantitative Inverse Pole Figures Using the Available Odf Data
Authors: Peng Charles , Ting Lu
Published: March 2019

The ODF calculation is, to a large extent, responsible for the increased interest in texture analysis. Accurate pole figures and ODF plots can be routinely obtained in the laboratory from x-ray units equipped with precision controlling devices. For studies of the plastic flow behavior of polycrystalline aggregates, it is important to present the texture results in a manner readily usable for these analyses. For samples having a simple concentrated texture, the presentation of the data in terms of conventional pole figures and ODF plots is usually adequate. Additional work however is frequently needed when the analysis is involved with a more complex texture. A method is described for constructing the quantitative inverse pole figure using the available ODF data. Attention is focused on the construction of inverse pole figures for FCC and BCC metals. Examples are given of the plastic flow analyses for copper and tantalum which were produced by different cold-forming processes to yield a multitude of texture elements. The modification and rearrangement of the computer program necessary to accomplish this task will be discussed.
Texture Measurement of Sintered Alumina Using the Marchdollase Function
Authors: Cline James P. , Vaudin Mark D. , Blended John E. , Handwerker Carol A. , Jiggetts Rodney , Bowman Keith J. , Medendorp Nicholas
Published: March 2019

The Rietveld method entails the calculation of a powder diffraction pattern from crystallographic, microstructural and equipment characteristics. These characteristics are related to the form of the pattern through a series of model functions. The difference between an observed and calculated pattern is then minimized by sequentially refining the physical parameters contained within the mode) functions to obtain an accurate and precise description of the specimen. A powder diffraction pattern from a specimen exhibiting cry stallo graphic texture, or preferred orientation, will display intensity values which differ systematically from those calculated for a specimen of random orientation. This systematic discrepancy can be addressed by incorporating into the Rietveld refinement a model function for sample texture. A successful model for texture will accurately assess the phase abundance and degree of texture from both oriented and randomized specimens. In this study we use the March-Dollase model function to characterize texture development in sintered alumina with respect to processing variables and sintering time.
Analysis of the Average Poly-Cyclic Aromatic Unit in a Metaanthracite Coal Using Conventional X-Ray Powder Diffraction and Intensity Separation Methods
Authors: Wertz David L. , Bissell Margaret
Published: March 2019

X-ray characterizations of coals and coal products have occurred for many years. Hirsch and Cartz measured the diffraction from several coals over the reciprocal space region from s = 0.12 Å-1 to 7.5 Å-1 where s = (4πλ) sine). In these studies, a 9 cm powder camera was used to study the high angle region, and a transmission type focussing camera equipped with a LiF monochromator was used for the low angle measurements. They reported that the height of the graphene peak (ca. 3.5 Å) measured for each coal is proportional to the % carbon in the coals. Hirsch also suggested that the ontyberem anthracite (94.1% carbon, 3.0% hydrogen, and 5.3% volatile matter with a specific gravity of 1.46) has a lamellar diameter of ca. 16 Å corresponding to an aromatic lamellae of ca. C87. For coals with lower carbon content, Hirsch proposed much smaller lamellae; C19 for a coal with 80% carbon, and C24 for a coal with 89% carbon.
Evaluating Indirectly the X-Ray Tube Spectra on the Basis of the Fundamental Parameter Method in Wavelength-Dispersive X-Ray Spectrometry
Authors: Szalóki I. , Magyar B.
Published: March 2019

Several calibration methods and empirical formulae have been developed so far for analyzing materials quantitatively in XRF spectrometry. Many of them require reference samples to determine the relationship between the characteristic intensities of the elements and their concentrations. In order to eliminate empirical and semiempirical procedures, the fundamental parameter method (FPM) has been developed, which is one of the most helpful evaluating tools in quantitative XRF analysis. Some interpretations of this approach have the advantage that no standard samples are needed. The simultaneous application of FPM and polychromatic excitation demand an exact mathematical description of the primary spectral distribution as well as the efficiency function of the detector system.
Study of Combustion Originated Ash Particles
Authors: Török Sz. , Fatgel Gy. , Osán J. , Török B. , W. Jones K. , L. Rivers M. , Sutton S.R. , Bajt S.
Published: March 2019

We are engaged in a study of the ash produced by combustion of lignite in a 750-MW power station. The aim is to follow the transport of elements with Z> 16 from the mine, through: a) the combustion process, b) emissionto the atmosphere or c) deposition in a land fill, d) transport in the environment and e) subsequent uptake by animals and humans. The resulting data will be used to estimate potential adverse impact on human health caused by operation of the power station.
X-rays Powder Diffraction Measurement in Reactive Atmospheres at 1000 °C and 7 MPa (1000 PSIG)
Authors: Mauer F. A. , Robbins C. R.
Published: March 2019

Studies of changes in the flexural strength and phase composition of castable refractories are being carried out in simulated coal gasification reactor environments. This paper describes a pressure vessel in which x-ray powder diffraction measurements can be made by an energy dispersive method while the specimen is being heated to temperatures as high as 1000°C in atmospheres containing H2O, CO2, CO, H2, CH4, NH3 , and H2S at pressures up to 7 MPa (1000 psig).
A Preliminary Report of the Design and Results of the Second Round Robin to Evaluate Search/Match Methods for Qualitative Powder Diffractometry
Authors: Jenkins Ron , Hubbard Camden R.
Published: March 2019

Six computer synthesized data sets, each representing a mixture, and one physical mixture were prepared and widely distributed in order to study the various search/match methods and factors which affect their success. A total of 67 returns were received representing eight countries and three search methods. The participants were primarily from industrial laboratories. The average score exceeded 90%. The Hanawalt search method yielded the best overall score. Use of the Frequently Encountered Phases subfile decreased the search time by about 40% and marginally increased the success rate. For the physical mixture the Δd/d and ΔI/I values were measured to about 2/1000 and 40% respectively. Use of an internal standard improved the d-values by a factor of 2 and resulted in better search/match performance.
X-Ray Diffraction Studies of Stabilities of Zeolties to Temperature Changes and Solution Treatment
Authors: Salek Hossein , Vincent Harold , Patton Melinda
Published: March 2019

Natural zeolite 1010A, mostly clinoptilolite, was found to be stable to prolonged heat treatment up to 600° C. Stability to treatment by acids and bases is dependent on solution strength, treatment time and temperature. Variations in intensities of diffraction lines correlate well with changes in exchange capacities for ammonium ions and other observed physico-chemical changes.
Applications of the Gandolfi X-Ray Camera in Minerals Industry Research
Authors: Corbett Ronald K.
Published: March 2019

The Gandolfi camera, which produces simulated powder diffraction patterns from single crystals, has been found to be a very useful tool in applied mineralogical research. For many micro-diffraction problems, the advantages of the method far outweigh its weaknesses, and Gandolfi films are usually quite adequate for identification purposes. A simple modification to the small Gandolfi camera permits the recording of low-angle reflections corresponding to d-spacings of nearly 14 angstroms for CuKα radiation. Applications of the method include identification of radioactive minerals, other heavy minerals, contaminants, and glass stones.
Instrumental Techniques for the Analysis of Paper Fillers and Pigments
Authors: Andrews Claude Robert , Mays Robert Kenneth
Published: March 2019

The chemical analyses of pigments and fillers are important to both the manufacturer and the papermaker. Most standard analytical methods, including those of Technical Association of the Paper and Pulp Industry, are based on the so-called classical gravimetric and volumetric techniques. The major components analyzed are TiO2, SiO2and Al2O3. X-ray diffraction methods are available for the identification of crystalline fillers and pigments in finished paper.
Residual Stress at Fatigue Fracture Surface of Heat Treated High Strength Steels
Authors: Komine Atsutomo , Ueda Hideo , Nakanishi Eisuke , Araki Shotaro , Taguchi Kazuo
Published: March 2019

Electron fractography has been widely applied to analyze fracture processes and service failures. However, the results obtained by the fractographic method are restricted to information in a topograph of the fracture surface. Therefore, other methods are needed to analyze the fracture. One of the hopeful advanced techniques is thought to be X-ray diffraction, because another type of structure sensitive information would be obtained.
Progress in X-Ray Fluorescence Correction Methods Using Scattered Radiation
Authors: Nielson K. K.
Published: March 2019

This paper reviews x-ray fluorescence (XRF) matrix correction methods which use scattered radiation and discusses their typical analytical applications. It also discusses some of the underlying assumptions of these methods and thus provides a basis for estimating their merits and limitations in quantitative analytical applications.
The Reduction of Matrix Effects in X-Ray Fluorescence Analysis by the Monte Carlo, Fundamental Parameters Method
Authors: Gardner R. P. , Doster J. M.
Published: March 2019

A review of the application of the Monte Carlo, fundamental parameters method to XRF fluorescence analysis for the reduction of matrix effects is made. The analytical solutions arising from theoretical equations are given along with the restrictive assumptions that are necessary to this approach. The extensions of the fundamental parameters method by the Monte Carlo simulation to practical situations that require much less restrictive assumptions are outlined. The average angle approach to the use of the analytical solutions is investigated by comparison with the Monte Carlo method. Future extensions of the fundamental parameters method by the Monte Carlo approach are discussed.
Quantitative Analysis of 300 and 400 Series Stainless Steel by Energy Dispersive X-Ray Fluorescence
Authors: Wheeler Bradner D. , Jacobus Nancy
Published: March 2019

Recent developments in analytical techniques and software have allowed the accurate quantitative determinations of both the major and minor elements in stainless steels by energy dispersive x-ray fluorescence. The successful analysis of 300 and 400 series stainless steel is reported utilizing this technique. The analysis of this type of material represents one of the most severe tests of the method due to numerous peak overlaps and interelement effects such as absorption and enhancement.

Sixteen standards of ASTM 300 series and ten 400 series were prepared by polishing on a 220 grit aluminum oxide belt and subsequently washing the surface in absolute methanol. Analyses were performed with an EG&G ORTEC 6110 Tube Excited Fluorescence Analyzer utilizing a dual anode (Rh/W) x-ray tube. Peak deconvolutions and interelement corrections were made with a 16K PDP-11/05 computer utilizing the program FLINT (1). Utilization of spectral deconvolutions and interelement corrections yields a relative accuracy of approximately IX of the concentrations of the major elements.
Computer Techniques for Faster X-Ray Diffraction Phase Identification
Authors: Goehner Raymond P. , Garbauskas Mary F.
Published: March 2019

This paper describes the procedures used to retrieve JCPDS powder diffraction data by certain characteristics. These characteristics may include chemistry, mineral name, highest intensity dspacing, largest dspacing, PDF number, etc. The storage scheme used for the powder data and the procedures used to enhance the retrieval speed are described.
A Method of Background Subtraction for the Analysis of Broadened Profiles
Authors: Enzo S. , Parrish W.
Published: March 2019

This method for precisely determining the background level of broadened x-ray profiles assumes that the background under the peak can be approximated by a straight line, and the decay in the tails several profile widths from the peak follows a Cauchy-like law. It uses a plot of I(s)s2 vs. s2 where I(s) is the intensity and the scattering vector s = 2cosθo sin(θ-θo)/ƛ where θo is the centroid, θ the Bragg angle and X the x-ray wavelength. The true background is determined by the slope of the linear portion of the plot and its extension to s2=0 gives the rate of decay of the tails. Results on synthesized and experimental profiles show that the method is useful for Warran-Averbach analysis, because it avoids spurious oscillations and the “hook” effect in the plot of the corrected Fourier coefficients, and makes it possible to correct for overlapping tails of adjacent reflections.
Stress Evaluation on Materials Having Non-Linear Lattice Strain Distributions
Authors: Hauk Viktor M.
Published: March 2019

The state of the art of stress evaluation on materials having non-linear lattice strain distributions is presented.

New results on heterogeneous materials with measurements conducted on both phases of the material show compensation of the shear stress components σ13 in ground surface layers of (α+β) brass. There is only the compensation of normal components σ11 of (α+γ) steel after plastic straining.

The fundamental aspects and the evaluation of macro- and microresidual stresses on materials having preferred orientation are broadened. The use of Mo-Ka-radiation shows linear lattice strain distributions, as a result of minimizing the influence of micro residual stresses causing oscillations. The interplanar distance- or strain-polefigure shows similarities with the intensity polefigure.

The knowledge of the theoretical influence of stress distribution with depth from the surface of the material is extended. The experimental procedure should use either different radiations having different penetration depths or a low-penetrating radiation in combination with removal of surface layers.
Determining Stresses in the Presence of Nonlinearities in Interplanar Spacing vs. Sin2ψ
Authors: Noyan I. C. , Cohen J. B.
Published: March 2019

The physical meaning of non-linearities in “d” vs. sin2ψ lines, encountered in X-ray measurements of surface residual stresses in polycrystalline materials is investigated. It is shown that when oscillations are present in any one reflection, switching to another reflection to obtain a straight line in “d“ vs. sin2.ψ is feasible only under very special conditions. We also discuss the effect of “quasi-homogeneous” strain distributions and investigate the effects of ψ-range on the accuracy of X-ray residual stress measurements when ψ-splitting” is present. A new geometric error is also discussed that can not be detected by the “annealed powder” method often used for alignment.
The Measurement of Elastic Constants for the Determination of Stresses by X-Rays
Authors: Perry K. , Noyan I.C. , Rudnik P.J. , Cohen J.B.
Published: March 2019

Residual and applied stresses (σij) are often measured via X-ray diffraction, by calculating the resultant elastic strains (ϵij) from the measured change in interplanar spacing (“d”). This method is non-destructive, reasonably reproducible (typically ±14 MPa), can be carried out in the field, and is readily automated to give values to an operator-specified precision , Let Lirepresent the axes of the measuring system with L3normal to the diffracting planes, and Pirepresent the sample axes. These axes are illustrated in Figure 1. In what follows, primed stresses and strains are in the laboratory system, while unprimed values are in the sample system.
Direct X-Ray Measurement of Residual Strains in Textured Steel
Authors: Gazzara C. P.
Published: March 2019

One of the most detrimental effects on the accuracy of an X-ray diffraction residual stress analysis, XRDRSA(l), is found in the examination of textured materials. The degree of elastic anisotropy and texture is in general agreement with the extent of the error in the residual stress. Several approaches have been made to correct for the effects of texture, particularly involving experimental techniques. Reviews of such efforts are given by H. D811e(2), v.M. Hauk﹛3) and G. Maeder, J.L. Lebrun and J.M. Sprauel (4), just to mention a few.

A brief chronology of the texture corrections involved in XRDRSA follows. With isotropic materials the d spacing of a crystal lattice, d, is assumed to vary linearly with sin2ψ. With textured materials the d vs sin2ψ relationship is nonlinear. This is due to the anisotropy of the elastic constants and their departure from a random distribution, or taking on a preferred orientation.
Stress Determination in an Adhesive Bonded Joint by X-Ray Diffraction
Authors: Predecki Paul , Barrett Charles S.
Published: March 2019

At the present time there is considerable interest in the use of adhesive bonded joints for structural applications. The design of such joints is based mostly on finite element calculations and failure tests rather than on strain or stress measurements. To our knowledge no measurements have been made of stresses at or near the adhesive/adherend interface (where many bond failures occur) because of difficulties with accessibility. The purpose of this work was therefore to try to make such measurements using X-ray diffraction.

The approach taken was to gain access to the bond by making one of the adherends in a single lap joint to be relatively transparent to X-rays and the cither relatively opaque. Incident X-rays then penetrated the first adherend and the adhesive and were diffracted from gains in the second adherend adjacent to the adhesive/adherend interface. Stresses resulting from curing of the adhesive were determined first, after which a load was applied and the stresses redetermined.
Evaluation of Straight and Curved Braun Position-Sensitive Proportional Counters on a Huber-Guinier X-Ray Diffraction System
Authors: Newman R.A. , Moore Kirchhoff P. , Fawcett T.G.
Published: March 2019

The interfacing of both straight and curved Braun Position- Sensitive Proportional Counters (PSPC's) to a high resolution Huber-Guinier camera system has been accomplished, resulting in a 10 to 100-fold decrease in data collection times when compared to conventional Guinier (film or scintillation counter) detector techniques.

Various factors causing line broadening were evaluated for both PSPC Guinier systems. The depth of the PSPC gas chamber was found to Have the greatest influence on line profiles. An R0% increase in peak half-widths was observed for PSPC-Guinier data compared to our highest resolution Guinier film data, but still yielded significantly better resolution than conventional powder diffractometer data obtained in our laboratory.
An Inexpensive In-House EXAFS Spectrometer
Authors: Georgopoulos P. , Tang C. H.
Published: March 2019

Given the vast superiority of synchrotron radiation sources for EXAFS and near-edge measurements, one might assume that conducting such experiments in the laboratory is a waste of time and resources. Upon more careful consideration of the realities of everyday research, however, one can easily see that this is not true. In fact, many people have come to this realization, so much so that a whole conference has been devoted to laboratory EXAFS facilities, their role in research and their relation to synchrotron facilities. The concensus after the conference was that laboratory instruments can and have been developed, with adequate performance for a variety of nontrivial experiments. They usually employ dedicated focusing spectrometers, rotating anode generators and fairly expensive monochromator crystals (see articles in ref. 1 and 2).
Line Broadening Studies on Highly Defective TiO2 Produced by High Pressure Shock Loading
Authors: Morosin B. , Graeber E. J. , Graham R. A.
Published: March 2019

Enhanced solid state reactivity of materials both during and after shock compression has been attributed to the introduction of large numbers of defects into the crystalline lattices and to reduction in the particle and crystallite size of powders [1]. In particular, orders of magnitude increases in the catalytic activity has been observed In shock-modified TiO2 [2]. Line broadening of x-ray diffraction profiles provides a means to determine the coherent crystallite size and the residual lattice strain resulting from defect concentrations. The present study on shock-loaded rutile is a detailed Investigation of the influence of shock loading on residual lattice strain and coherent crystallite size. Annealing of shock-modified rutile powders is also studied.
High Temperature Guinier X-Ray Diffractometry for Thermal Expansion Measurements in the Hexagonal form of Cordierite ((2MgO•2Al2O3•5SiO2)
Authors: Pressnall J. S. , Fitzpatrick J. J. , Predecki Paul
Published: March 2019

A computer-controlled high temperature Guinier diffractometer system for accurate determination of lattice thermal expansion is described. A critical test of the system using α-Al2O3 (0.3μ polishing alumina) showed close agreement with the single crystal expansion data of Wachtman et al. Lattice thermal expansion of cordierite doped with the following dopants: Ge+4, P+5, Zn+2, Li+1 and Ca+2 was investigated. Of these the Li+1 at the 5% level (5% of Si+4 replaced by Li+1 + Al+3) produced the largest decrease in mean lattice expansion.
Investigation of Obsidian by Radioisotope X-Ray Flurescence
Authors: Robie Stephen B. , Preiss Ivor L.
Published: March 2019

The classification of obsidian artifacts has been receiving considerable attend of changes in obsidian trace element composition can now be identify ancient trade routes. The classification of this glassy volcanic material has been attempted using a variety of elemental analysis technique. The most successful and most widely employed method of non-destructive analysis has been that which employs X-ray fluorescence analysis (XRF); either wavelength dispersive (WDS), or energy dispersive (EDS).
X-Ray Fluorescence Spectrometric Analysis of Uncontaminated and Contaminated Tropical Plant Materials for Traces of Heavy Metals
Authors: Schorin Hasso , Piccioni Laura
Published: March 2019

52 elements of the periodic system are considered as potentially usable by living organisms. Most of them, as some heavy metals, are required only in trace amounts. If a certain concentration of a given trace element is exceeded in an organism it becomes toxic. Plant analyses are considered in agronomy as a diagnostic tool and as a guide to fertilizer practice as the plant uptake is the best criterion of nutrient and micronutrient availability. But nowadays also toxic metals may be assimilated by plants due to the increasing contamination by inorganic compounds containing these toxic elements. In geosciences plant analyses may be of importance because indicator plants are employed for the geochemical prospection of certain heavy metals.
Instrumentations and Applications for the Soft and Ultrasoft X-Ray Measurements
Authors: Kohno Hisayuki , Arai Tomoya
Published: March 2019

The development of X-ray fluorescence analysis of light elements (e.g. O, C, B and Be) has been carried out for many applications. Recently, the revolutional expansion of semiconductor electronic and memory devices has roused the needs of analysis and identification of the surface and the single- and multi-layered film structure in devices, using the fundamental parameter method for the soft and ultrasoft X-ray region. From the view point of the extensive studies of soft and ultrasoft X-ray measurements.
Diffraction Peaks in X-Ray Spectroscopy: Friend or Foe?
Authors: Tissot Ralph G. , Goehner Raymond P.
Published: March 2019

Diffraction peaks can occur as unidentifiable peaks in the energy spectrum of an x-ray spectrometric analysis. Recently, there has been increased interest in oriented thin polycrystalline films and epitaxial films on single crystal substrates for electronic applications. Since these materials diffract x-rays more efficiently than randomly oriented polycrystalline materials, diffraction peaks are being observed more frequently in x-ray fluorescent spectra In addition, micro x-ray spectrometric analysis utilizes a small, intense, collimated x-ray beam that can yield well defined diffraction peaks. In some cases these diffraction peaks can occur at the same position as elemental peaks. These diffraction peaks, although a possible problem in qualitative and quantitative elemental analysis, can give very useful information about the crystallographic structure and orientation of the material being analyzed. The observed diffraction peaks are dependent on the geometry of the x-ray spectrometer, the degree of collimation and the distribution of wavelengths (energies) originating from the x-ray tube and striking the sample.
Elemental X-Ray Imaging of Fossils
Authors: Morton R. W. , Witherspoon K. C.
Published: March 2019

This paper describes the imaging of fossils using elemental x-ray area mapping (EXAM). The technique utilizes a commercially available instrument originally designed for the silicon chip industry. The EXAM data are processed digitally with imaging software to remove surface irregularities and enhance specimen details. Applications of this technique to specimens with irregular surfaces are described.
Quantitative XRF Determinations of Additive Elements in Greases for Manufacturing Specifications
Authors: Sieber John R.
Published: March 2019

Additive elements are now included in manufacturing specifications for greases. Texaco uses X-ray fluorescence at lubricants manufacturing locations; however, analyses of greases in the neat form are difficult due to problems with uniform and repeatable filling of sample cups and outgassing of greases during measurements. This preparation procedure allows quantitative determinations of additive elements in a variety of greases using a single analytical program. Having a single method for all greases is important at busy manufacturing locations.

The preparation method involves dilution of samples in a binder powder. This approach eliminates outgassing and overcomes differences among greases such as type of soap, presence of MoS2 and graphite, and varying oil content. The powder absorbs oil and creates a uniform particle structure. Thorough mixing and careful cup packing yield repeatable measurements. The method allows the use of liquid oil standards for calibration, eliminating the need to obtain analyzed greases. Accurate calibrations have been created for both wavelength-dispersive and energy-dispersive spectrometers.
Grazing Incidence X-Ray Characterization of Materials
Authors: Bowen D.K. , Wormington M.
Published: March 2019

A review of the methods of characterization of materials using X-rays incident at grazing angles is presented. The rationale of all such methods is the need to obtain information from near-surface regions. The methods include grazing incidence diffraction, reflectivity, diffuse scatter and fluorescence. The experimental techniques are outlined, and the information obtainable and the methods of interpretation are discussed.
Structural Characterization of Magnetic Recording Media by Using Grazing Incident and Conventional X-Ray Diffraction
Authors: Wang Po-Wen
Published: March 2019

In recent years, the microstructure of Co-based alloy magnetic thin film disks has been studied extensively by using a conventional x-ray diffraction (XRD) technique(1-4). Efforts to understand the relationship between the microstructure and the magnetic properties of disk had been limited due to the lack of depth resolution in the conventional theta-2theta scanning technique. In this paper, a fixed 0.5 degree of grazing incidence(5) 2-theta scan X-ray diffraction (GIXRD) technique was used to characterize the thin film disk microstructure and therefore to correlate with the magnetic properties.
Proposed Methods for Depth Profiling of Residual Stresses using Beam-Limiting Masks
Authors: Predecki Paul , Ballard B. , Zhu X.
Published: March 2019

Methods are described which make use of x-ray absorbing masks to either limit beam penetration in the sample (Type I), or confine the diffracting volume within definite limits (Type II). The masks consist of a metal film of Au or U, containing many long, parallel apertures of effective width w and spacing c. The mask is either applied directly to the sample surface (Type I), or to a weakly absorbing film (Be or Kapton) on the sample surface (Type II). With the Type I mask, the diffracting volume can be limited to a surface layer whose maximum depth zm at ψ=0 varies linearly with w, irrespective of sample or wavelength. The masks can be used with ψ-tilts in an Ω-type goniometer, and strains and stresses can be determined by the Sin2ψ method. Depth profiles as a function of depth z (z-profiles) can be obtained with layer removal if gradients over the depth Zm can be neglected. With the Type n mask, the diffracting volume can be limited to a discrete subsurface layer whose average depth depends on (c+w) and the Bragg angle 2θ, and whose thickness depends on w and 2θ. z-Profiles can be obtained by varying the wavelength for a given reflection using a synchrotron source, without the need for layer removal. The methods have not yet been tested experimentally.
NIST SRM 2708, Zinc Sulfide Thin Film on Polycarbonate for X-Ray Fluorescence Spectrometry
Authors: Pella P.A. , Kelly W.R. , Murphy K.E. , Steel E.B. , Schiller S.B.
Published: March 2019

NIST SRM 2708 is a thin film of zinc sulfide approximately 0.02 μm thick that was sputter deposited on polycarbonate substrates using a NIST ion-beam instrument. It is intended for the standardization of x-ray fluorescence spectrometers, especially for analysis of air particulates or similar material collected on filter media.
A Simple Approach to Multilayer Thin Film Analysis Based on Theoretical Calculations Using Fundamental Parameters Method
Authors: Feng Liangyuan
Published: March 2019

Since more than a decade ago, the topic of multilayer thin film analysis using Fundamental Parameters (FP) method has been addressed by many authors. However, as a general approach to the implementation of this method, an iteration must be applied directly with the theoretical equations. In many cases, this procedure can become very time-consuming and sometimes cause divergence problems, especially when a complicated layer structure is involved or some special requirement for the analysis must be satisfied. In this work we adopted a new approach to the analysis of some types of multilayer thin films, which is conceptually similar to die well known theoretical alphas method used in bulk sample analysis in the sense that they all use FP theoretical calculations to establish mathematical relationships between the XRF intensity and the quantities of interest.