bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Blazed-Grating Scanning Spectrometer for Ultrasoft X-Rays Suitable for Use in an Electron Microprobe
Authors: Nicholson J. B. , Hasler M. F. 
Published: March 2019

AbstractThe importance of operating within the blaze angle is emphasized by a series of measurements of ultrasoft X-rays obtained with a new grazing-incidence, grating spectrometer, A formula to maximize output intensity has been derived which predicts a variation of input angle with changes of wavelength. The spectrometer is designed to utilize this function. The grating spectrometer was installed into an Applied Research Laboratories Analyst's Microprobe. Since the AMX furnishes an utt.rasoft spectrometer with a fatty acid pseudocrystal as standard equipment, it is possible to compare the two systems simultaneously on the same sample at the same wavelength. The grating and crystal systems are compared for peak intensity and line-to-background ratio.
Some Observations on the Use of Certain Analyzing Crystals for the Determination of Silicon and Aluminum*
Authors: Chan Frank L. 
Published: March 2019

AbstractDuring the past several years, a number of analyzing crystals have been prepared in the U.S. Air Force Aerospace Research Laboratories. Crystals such as alkaline acid malonates, sucrose, pentaerythritol (PET), and several others have been grown with the sole purpose of application in X-ray fluorescence analysis of silicon, aluminum, and other elements of low atomic number. Crystals from natural sources, such as quartz, mica, and gypsum, have also been procured from different parts of the world for this purpose.Among the analyzing crystals so prepared, pentaerythritol gave the highest count rate for silicon and aluminum. However, since this crystal is organic in nature, great care must be exercised in handling this type of crystal in order to obtain constant count rates. For the analysis of silicon and aluminum, a-quartz crystal gave a somewhat low count rate, but this crystal has certain advantages over the organic crystals, and can be used for analysis of materials having high silicon and aluminum content.For instance, when using a conventional X-ray emission vacuum spectrograph of standard make, with the latest alterations, one of the PET crystals attained a count rate of 101,870 cps for pure silicon when the instrument was operated at 60 kVP and SO m A with a negligible background count. With a constant potential attachment and operated at 60 kVP and 34 mA, 1.15,600 cps with negligible background count was obtained for silicon. The count rate for aluminum was of the same order of magnitude with somewhat higher background count.Several sets of standards have been procured and small amounts of silicon and aluminum in these standards have been analyzed by the latest modified vacuum spectrograph. These results are under study and the limit of detection calculated. Procedures and results are described and discussed.
X-Ray Spectrographic Analysis of Automotive Combustion Deposits Without the Use of Calibration Curves
Authors: Wagner J. C. , Bryan F. R. 
Published: March 2019

AbstractArt X-ray spectrographic technique requiring no calibration curves is used to determine chlorine, bromine, and lead in automotive combustion deposits. Other elements, such as zinc and barium, can probably be determined by the same X-ray technique. The inert dilution method, described by Sherman in 1957, is employed. Improvements in sample preparation have been made to make the procedure more reliable. Results are calculated by the use of a formula, which is shown to be valid even though sample and standard have composition differences which cause interelement-effect errors if calibration-curve techniques are used. Adequate agreement is obtained between the inert dilution X-ray method and chemical procedures.
Composition and Lattice Constant Evaluation of the Garnet System (Dy, Gd)3Ga5O12
Authors: Moudy L. A. , Austerman S. B. 
Published: March 2019

AbstractCompositional and lattice constant control of non-magnetic garnet substrates are required for suitable lattice matching with epitaxially deposited magnetic thin film. Suitable substrates for this purpose are the simple and mixed rare earth garnets. Lattice constants were obtained on Czochralski grown crystals by conventional x-ray diffraction powder techniques with a precision of ± .0005Å. An x-ray fluorescence method was developed to determine crystal composition with a precision of ± 0.5 percent. The precision with which a can be determined indirectly by x-ray fluorescence is ± 0.0082Å, which is comparable with that from direct measurement.
New Improvements in Routine Quantitative Phase Analysis by X-Ray Diffractometry
Authors: Sahores J.J. 
Published: March 2019

AbstractThe principle of the method that we proposed two years ago (1) to correct the matrix effects in quantitative diffractometry is briefly recalled and recent improvements are described. Some examples taken in geological field illustrate its possibilities.A new field of application has been explored : thanks to a combination of this method with background measurement, a semi-quantitative estimation of the amount of amorphous material is made possible in any sample.This correction technique can be used with any regular diffractometer : for this purpose we simply need to add a second measuring channel, the characteristics of which are given.Finally we describe briefly the complementary electronics which have been designed in order to fully automate the apparatus, from the insertion of the samples to the printing of the results.
The Processing of Energy Dispersion X-Ray Data in a Timesharing Computer
Authors: Marr Harold E. , Campbell William J. 
Published: March 2019

AbstractA time-sharing computer was used in conjunction with a semiconductor detector and radioisotopic sources to evaluate energy dispersion x-ray analysis for the rapid analysis of copper base alloys. The time-sharing computer served two purposes: to aid in the development of the analytical method and to simulate the action of a dedicated computer that would eventually be used as part of an on-line analytical device. Some of the general capabilities of time-sharing computers are discussed in this paper with some emphasis on the differences between the computer requirements of energy dispersive x-ray methods and conventional x-ray spectrography.An annular source of americium 24l was used with a secondary fluorescer to excite 23 brass and bronze alloys. The 400 channel spectrum from a multichannel analyzer was recorded on paper tape. A telephone coupled teletype was used to transmit the X-ray spectrum to the central processing facility. Curve fitting and statistical analysis programs similar to those available from most commercial time-sharing computer operations were utilised as well as other programs written at this laboratory for processing digitized spectra.
Evaluation of the Energy Dispersive Detector as a Detector-Filter System for the X-Ray Diffractometer
Authors: Carpenter Davis , Thatcher John 
Published: March 2019

AbstractA comparison of the relative merits of the energy dispersive derector-pulse height analyzer, scintillation detector-graphite monochromator, and proportional detector-pulse height analyzer combinations.Typical energy dispersive detectors are not configured for maximum efficiency on the diffractometer. Being only on the order of 3 mm diameter, a good deal of the available information is not collected by the detector. This is especially true with the Wide optics found in modern diffractometers. The energy dispersive detector incorporated into this system is optimized for the x-ray diffractometer. Its detection area is a 1.25 X 0.25 inch rectangle. The resolution is only sufficient to remove the Kβ portion of the spectrum.Conventional diffractometer techniques incorporate either a scintillation detector-crystal monochromator, or a proportional detector-pulse height analyser combination. The question posed is “what are the advantages in signal to noise ratio and pulse height distribution of the energy dispersive-pulse height analyzer over the more conventional arrangements.”
Intensity Correction Factors for X-Ray Diffraction Measurements of Residual Stress
Authors: Short M. A. , Kelly Carol J. 
Published: March 2019

AbstractThe angular dependent factors which affect the intensities of X-ray diffraction line profiles, as observed on a Standard X-ray diffractometer, are well established. They are the Lorentz factor, the polarization factor, the atomic scattering factor, and the temperature factor. For residual stress analysis, in which measurements are made at non-zero omega (psi) angles, an absorption factor must be added to this list. It is usual, however, in residual stress analysis, to omit two of these factors: the atomic scattering factor and the temperature factor. The omission of these two factors appreciably alters the change in the combined correction factor with change of diffraction angle. The proper angular dependent corrections are in the opposite sense to those customarily employed. The effect of the additional factors on measurements of residual stress are discussed.
X-Ray Diffraction Contrast from Impurity Precipitates in CdS Single Crystals
Authors: Chikawa Jun-ichi 
Published: March 2019

AbstractImpurity-doped crystals CdS(GaGl3) have been studied by X-ray topography. Some large precipitates are formed close to the crystal surfaces by annealing at 300°C. In the symmetrical Laue case, the precipitates show circular images (30-60 μ in diameter) due to the radial strains around the precipitates which consist of two semicircles separated by a contrast-free plane parallel to the reflecting plane. The observations indicate that the strain field between the crystal surface and precipitate is not responsible for the contrast, and that the images are formed by X-rays which are deviated from the Bragg condition for the perfect region and satisfy the Bragg condition in the strain field on the inside of the precipitate. One of the semicircles is formed by the incident X-rays with larger glancing angles than the Bragg angle and the other with smaller ones. It is concluded that this contrast is due to the strain around a convex lens shaped precipitate.
Lang X-Ray Topographic Studies of Ruby Grown by Different Methods
Authors: Belt Roger F. 
Published: March 2019

AbstractCrystals of ruby (Al2O3:Cr) are being grown at the present time by several standard procedures, e.g., Verneuil, Czochralski, flux, and hydrothermal. Previous work has indicated wide variations in quality and type of defects. The present study is primarily concerned with ruby grown from PbO-PbF2 fluxes. All crystals were examined in transmission with Mo Kα1 radiation and a Rigaku Denki Lang camera. Samples were either sectioned from larger crystals or obtained as plates with natural growth faces. Results on flux-grown ruby have shown a severely banded substructure due to strain introduced by either the flux or chromium segregation. Crystals with a visible chromium gradient have shown fewer bands in those regions which were depleted of chromium. Annealing studies have been performed on ruby and all banded structure was dispersed into areas of fine particles with a much higher dislocation content. Other features of the substructure are described. These include the observation of Pendellosung fringes in wedgeshaped sections. Areas of nearly 0.5 cm2 were found to be dislocation free. The X-ray results confirm etching experiments but the former yield more information on internal details other than dislocations.Recent data on sapphire (α-Al2O3) have confirmed several tentative conclusions. Flux grown crystals have some bands due to flux segregation. However, sapphire crystals show higher perfection when compared to ruby. These results have been confirmed by rocking curves obtained on a double crystal X-ray spectrometer used in the parallel position. Measurements on the (00.12) reflection from the natural growth faces were performed with Cu Kα1 radiation. Widths at half the maximum intensity were always found to be larger for ruby than for sapphire. Comparisons were made with respect to a perfect silicon crystal in the same geometry. Some preliminary experiments have been performed on Czochralski ruby prepared by the Linde Company and on hydrothermally grown ruby prepared at Airtron, Examples of defects observed in each case are given. They are highly unique to the growth method. The Lang method is shown to reveal more detail than other X-ray data. A brief discussion of ruby quality as a function of growth method is presented.
The Expansion upon Cooling of Thick Cu2O Films Grown on Copper Substrates
Authors: Swank T. F. , Lawless K. R. 
Published: March 2019

AbstractDuring the course of catalytic experiments on bulk copper single crystals, several crystals were intentionally oxidized to form thick (6000 Å) Cu2O films on the copper substrates. These oxidized crystals were investigated by means of a high temperature chamber installed on a General Electric XRD-5 X-ray diffractometer. It was discovered subsequently that the lattice spacings of the Cu2O decreased upon heating and increased upon cooling. Bulk single crystals and polycrystals of copper were oxidized at 3 Torr of air for several hours. All of the oxidized crystals were examined with copper and chromium radiation and both showed similar results. Typical of the results was an oxidized (110) copper disc which showed a net contraction upon heating of 1% for the (110) Cu2O planes. This slightly oriented Cu2O film was distinguished because -it contracted on heating to 440°C from room temperature, then expanded from 440°-540°C, and then expanded again when cooled from 540°C to room temperature. CuO also was detected in the diffraction pattern and the CuO and copper spacings were behaving normally with the temperature changes. A polycrystal of Cu2O was'examined and that, of course, also acted normally as its temperature was varied. Borie and co-workers have reported and explained very nicely similar anomalous behavior for thinner (500 Å) (110) oriented Cu2O films grown on (110) copper substrates. They showed that the epitaxial forces would cause an oxide film grown at high temperatures to contract parallel to the metal interface and expand normal to the interface as the copper cools and contracts. The oxide would expand normal to the surface in. order to keep its unit cell volume constant.It is felt that epitaxial forces are not causing the anomalous behavior in the present work mainly because the 6000 Å of Cu2O is too thick for epitaxy to exert a meaningful force. The oxide film on the (110) copper was slightly (110) oriented but all of the Cu2O reflections behaved similarly. An additional reason to discount epitaxy is that this Cu2O film expanded upon heating from 440°-540°C. For these thick oxide films epitaxial forces do not seem to be the controlling factor; therefore, a point defect mechanism must be the cause. Changing oxidation and diffusion rates with temperature would produce various vacancy concentrations in the oxide layer and cause the spacings to vary.
New Results on the Iron-Nickel Equilibrium Diagram-The Gamma/Gamma-Plus-Alpha Boundary
Authors: Ananthanarayanan N. I. , Peavler R. J. 
Published: March 2019

AbstractSolid state equilibria in iron-nickel alloys containing 0-65 at % nickel were studied by X-ray diffraction techniques, and the gamma/gamma + alpha boundary has been relocated.Alloys were prepared by thermal decomposition and hydrogen reduction of mixed-crystal iron—nickel formates and by distilling off mercury from mixed ironnickel “amalgams,” both methods of preparation yielding equilibrium alloys in relatively short time at temperatures below 500°C, Alloys were studied at various temperatures by use of a high-temperature diffraction camera, or at room temperature as quenched from the temperature of preparation.The study showed that the gamma/gamma + alpha boundary lies at generally higher temperatures than in previous diagrams and is concave downwards instead of upwards. The boundary shows three discontinuities which have been located to lie at approximately (a) 3 at % nickel and 760°C, (b) 35–43 at % nickel and S25°C, and (c) 50 at % nickel and 330°C. These discontinuities indicate the possible existence of three isobaric invariant three-phase equilibria, heretofore, undetected in the iron-nickel system. Further studies covering the entire range of iron—nickel alloy compositions are in progress.
Line Shape Analysis of Deformed Cu-Ge Alloys
Authors: Ahlers M. , Vassamillet L. F. 
Published: March 2019

AbstractThe asymmetry of diffraction peaks of deformed α-Cu-Ge alloy filings is determined by the center of gravity and Fourier coefficient method with computer calculations. It is shown that it is not possible to describe the asymmetry by a simple value that is a characteristic of the extent of the deformation and the Miller indices of the peak. Instead the asymmetry is highly dependent upon the initial arbitrary conditions for evaluation, which throws some doubt on the reliability of published twin fault and stacking fault probabilities.
Numerical Control X-Ray Powder Diffractometry
Authors: Rex R. W. 
Published: March 2019

AbstractRecent development of numerical control, N/C, systems for digital X-ray powder diffractometry opens the full potential for rapid and detailed machine processing of digital diffraction data. This capability may prove to be as large an incremental technological advance as the earlier shift from film to counter detector techniques. Our N/C system has the capability of performing essentially all operations possible by manual methods. Data output is on magnetic tape and carries identification, and some of the instructions necessary for processing. The data tapes are processed by programs that (a) edit and check, (b) filter through a controlled shape high frequency filter (square, triangular, normal, etc.), (c) remove the minimum background from the diffraction pattern, (d) analyze data points close to background and test for statistical significance deleting those points within limits defined to constitute noise, (e) recognize peaks and record their position and intensity, (f) identify phases, (g) calculate phase concentrations by various methods, including internal standard and mutual standard techniques, and (h) output any desired portion of the data in a variety of digital and analog formats suitable for display, further analysis, and storage in an information retrieval system.It is possible to record an entire diffraction pattern for a phase on two or three inches of magnetic tape. This record carries detailed peak area and shape information now missing from the ASTM reference system. Furthermore, the new magnetic tape information is directly amenable to computer processing to prepare search oriented record systems of diffraction data that can be inexpensively updated and edited. Currently, an ASTM committee is preparing a magnetic tape format diffraction pattern file. It is suggested that a second generation, computer index system be generated based on digital records of actual diffraction patterns. This type of system should prove more versatile than the old system and possibly be the only way to keep abreast of the flood of new diffraction pattern information generated from the vast number of new organic and inorganic compounds being synthesized.
The Analysis of the Light Elements in Ferrotitanium Ores and Residues of Widely Varying Composition by X-Ray Spectrography
Authors: Sanderson Benjamin S. , Yeck James A. 
Published: March 2019

AbstractFerrotitanium ores and residues may vary widely in composition. Because of this, interelemerxt effects are very large. An X-ray spectrographic method will be described for the analysis of the light elements in these ores and residues. The method uses a standard helium path Norelco spectrograph with a tungsten target tube. A KAP analyzing crystal is used for all the elements investigated. Appropriate emission lines of the elements magnesium, aluminum, silicon, calcium, titanium, and iron are measured and the results are calculated on a small computer using the empirical corrections for interelernent effects of Lucas-Tooth and Pyne. The FORTRAN program for these calculations will be given.The problems of sample preparation, standardization, interferences and instrumental variables will be discussed. A comparison of X-ray results with chemical analysis is made.The method is especially adaptable to automated analysis and some of the systems needed will be outlined. The method may also be modified to analyze light elements in other matrices.
Recent Advances in Quantitative X-Ray Spectrometric Analysis by Solution Techniques
Authors: Bertin Eugene P. 
Published: March 2019

AbstractUsually X-ray spectrometric analyse? of samples in their original forms—solid, powder, small fabricated parts, liquid, etc.—are more rapid and convenient than analyses by any other method. Thus, the analyst is well advised to strive to analyze samples in their original form whenever practical. However, it is often necessary to reduce nonliquid samples to some other form, for example, when standards are unavailable in the original form, when the same substance is received for analysis in a variety of forms, when homogeneity or matrix effects are severe, or when an internal standard must be added. In such cases, samples and standards are often reduced to a powder, a fusion product, or a solution. If the decision is made to put the sample into solution, the many well-known advantages of solution techniques are realised, including: (1) homogeneity; (2) easy preparation of standards and blanks; (3) easy concentration, dilution, separation, and other treatment; (4) reduced matrix effects and wide choice of ways to deal with matrix effects; (5) wide choice of ways to present the specimen to the spectrometer; and (6) applicability of internal-standard, standard-addition or -dilution, indirect, absorption, and scatter methods. This paper reviews work reported since 1960 in which the specimen is presented to the spectrometer in liquid form. The review is not particularly critical and stresses experimental techniques and treatment of data rather than specific materials and results. The work is discussed in the following categories: (1) sensitivity ; (2) liquid-specimen cells; (3) interaction of primary beam and liquid specimens; (4) matrix effects; (5) indirect (association) analysis; (6) X-ray scatter methods; and (7) X-ray absorption-edge spectrometry.