bluuebunny/crossref_metadata_2025_split huggingface dataset:
X-Ray Diffraction Investigation of BeO Calcination Processes
Authors: Rau R.C. 
Published: March 2019

AbstractTo aid in the study of the preparation and properties at BeO, X-ray diffraction investigations were performed to determine the various phases and transformation temperatures occurring in the different BeO calcination processes and to determine the theoretical density of the final BeO product.The hydroxide, sulfate, and oxalate of beryllium were the starting materials in the three calcination series. The samples studied were prepared by heating small portions of the starting materials for 1 hr at various temperatures and slow cooling. Analysis of the hydroxide series showed a direct conversion from Be(OH)a to BeO by simple loss of water. However, both the sulfate series and the oxalate series go through a series of intermediate phases in transforming to BeO. X-ray data and structure information have been obtained for most of these phases, and temperature ranges of their occurrence have been established.Wherever possible, the X-ray results have been compared with results of stereoscopic and polarizing microscope examinations, and temperature range of occurrence have been compared with thermal balance curves.
X-Ray Diffraction Investigation of Vacuum-Deposited Metallic Films
Authors: Renius Otto 
Published: March 2019

AbstractIn the course of work on the vacuum deposition of metallic films, a series of X-ray diffraction investigations was run on the effects of base material orientation, heat treatment, and angle of deposition, on the structure of the deposed films. Results show that the film structure can be altered by changing several parameters during and after the deposition process. An attempt is made to correlate this structure with film adhesion and protective characteristics.
A Technique for Studying Coprecipitated Chromia-Alumina Catalysts by X-Ray Diffraction
Authors: Kehl W. L. 
Published: March 2019

AbstractA diffractometer equipped with a gas proportional counter and pulse-height analyzer provides a very satisfactory means of recording the X-ray diffraction patterns of chromium-containing materials with Cu Kα radiation. The fluorescent chromium K radiation can be rejected along with much of the white background radiation without appreciable loss of Cu Kα intensity, and the advantages of copper over chromium or molybdenum radiation can be fully utilized. This is illustrated by an X-ray diffraction study of coprecipitated chromia-alumina catalysts, in which the chromium concentration varies between 0 and 37 w, %. At each chromium concentration the precipitate was studied in the washed and dried state, as well as after calcination at 500, 750, and 1400°C. X-ray diffraction patterns are presented to show the phase transformations and sample inhomogenelties that were observed.
A Study of Phase Reactions in a Complex 4.5 Al–3.5 Ti–Ni Base Alloy
Authors: Radavich John F. , Boesch W. J. 
Published: March 2019

AbstractAn investigation of the phase changes in a complex aluminum-titanium-hardened nickel-base high-temperature alloy was carried out after solutioning at high temperatures and aging at lower temperatures. The physical distribution and size of the precipitated phases were studied by electron microscopy. X-ray diffraction and fluorescence analyses were carried out on chemically extracted residues. The results of the xtructure changes as well as correlation of some physical properties with the structural changes are presented.
Fluorescent X-Ray Spectrographic Analyses of Amphibolite Rocks and Constituent Hornblendes
Authors: Chodos A. A. , Engel Celeste G. 
Published: March 2019

AbstractFluorescent X-ray spectrographic analyses have been made for the oxides Fe2O3 caO, MgO, K2O, TiO2, and MnO on samples of amphibolite rock. In addition, the above oxides and SiO2 and Al2O3 have been determined in a suite of constituent hornblendes from these rocks.Classical wet chemical analyses of materials of the same minera logical composition as the samples are used to establish the working curves. This eliminates the necessity for Internal standardization or other treatment of the samples. The only sample preparation involves extremely fine grinding before analysis.Precision of the analyses is equivalent to, or better than, that achieved by wet chemical methods.
X-Ray Spectrometric Determination of Copper, Tin, and Uranium in Bronze Heat-Treating Material*
Authors: Blank G. R. , Heller H. A. 
Published: March 2019

AbstractA method is presented for the X-ray spectrometric determination of copper, tin, and uranium in a bronze heat-treating material. The method is based on the irradiation of an acid solution of the sample, to which indium and zinc have been added as internal standards. Quantitative determinations of copper and tin (each in the 40 to 60% range) are calculated from the ratios of the CuKα/ZnKα and SnKα/In Kα intensities. Uranium concentration (in the 1 to 10% range) is calculated from the ratio of the ULα/ In Kα intensities, A correction for the interference of the second-order In Kβ1,3 doublet with the first-order ULα peak is described. The over-all limits of error for single determinations at the 95% confidence level are ±0,58% copper, ±0,56% tin, and ±0,31% uranium.
Crystal Structure and Stability of Refractory Phases
Authors: Nowotny Hans 
Published: March 2019

AbstractThis paper deals with some recent investigations on beryllides, borides, carbides, nitrides, aluminides, and germanides of transition metals as well as with combinations of these with special reference to hafnium and uranium compounds. The results will be discussed within the general field of refractories excluding the class of typical oxides. An intense study has revealed the influence of metalloid impurities (for instance carbon, nitrogen, and oxygen on high-melting borides and silicides or nitrogen and oxygen or carbides, respectively). Very often small amounts of such metalloids introduced by preparation techniques, like hot-pressing, sintering, and powder-reaction methods may change the constitution of the system.
Some Recent Developments in the Direct Viewing and High-Speed Recording of X-Ray Diffraction Patterns
Authors: Goetze G.W. , Taylor A. 
Published: March 2019

AbstractExperiments on the application of X-ray image intensifiers of the Fluorex type and of transmission-type secondary electron image intensifies (Astracon tubes) to the direct observation and recording of X-ray diffraction patterns have proved highly successful. Further improvements can be obtained by combining a Fluorex tube directly with an Astracon tube. By this means, the useful signal strength is so improved that movies at standard frame speed can be made which record the changing Laue pattern from a rotating crystal. It is shown how still further improvements are possible if the optical coupling in the system is improved by incorporating a fiber-optics window at the input of the Fluorex-Astracon tube. It is further indicated how a fiber-optics adapter can be used as an analog computer to convert the X-ray diffraction pattern from a single crystal into an exact representation of the reciprocal lattice which can be viewed directly.
Method for Finding Mass-Absorption Coefficients by Empirical Equations and Graphs
Authors: Leroux J. 
Published: March 2019

AbstractA brief description of the theoretical approach of this new method is given. The main purpose of the method is to correlate in a more logical order not only the data yielding the two laws relating mass-absorption coefficient to wavelength and to atomic number, respectively, but also to delineate, within two discontinuities, the relationship existing between each value and the other ones taken as a whole. The empirical equation relating μ to λ is μ = Cλn. A table of complete values for the constant C and die power n to be assigned in the equation is given for finding the values of mass-absorption coefficients above unity for all elements (except hydrogen) and for all wavelengths between 0.17837 and 10 A. It is believed that until a complete set of experimental data obtained with modern equipment is available, this proposed method fills the enormous gaps between actual compiled values.
Use of a High-Temperature X-Ray Diffractometer to Measure the Temperature Dependence of Reflection Intensities*
Authors: Ryba Earle , Chiotti P. 
Published: March 2019

AbstractThe temperature dependence of the reflection intensities from copper was examined in order to determine the mean-square vibration amplitudes of the atoms in the metal. The reflections from a prealigned single crystal were examined in a Norelco diffractometer outfitted with a high-temperature chamber designed by Chiotti. The intensities of the (400) reflection for copper were measured at temperatures from 13 to 1000°C. Difficulty was experienced in obtaining reproducible intensity measurements, and it is suggested that this was due to changes in the mosaic structure of the single crystal during thermal cycling.
Microanalysis with Ultrasoft X-Radiations*
Authors: Henke Burton L. 
Published: March 2019

AbstractThe diffraction, reflection, absorption, fluorescence, and the electronic emission that results from the interaction with ultrasoft X-rays (λ > 10 A) are presented as practical bases for microanalysis. Recent developments on sources and detectors for the ultrasoft X-radiations are described. A preliminary report on a current investigation on low-energy photo-Auger electron analysis and on a new type of low-energy electron spectrometer is also presented.
The Geometrical Representation of Ternary Alloys and its Applications to X-Ray Fluorescence and Microprobe Analysis
Authors: Taylor A. , Kagle Brenda J. , Beiter E. W. 
Published: March 2019

AbstractA simple and accurate graphical method is described for converting the composition of ternary alloys from weight per cent to atomic per cent, and vice versa. By making certain simplifying assumptions, the principles of the method are extended to the approximate determination of ternary alloy compositions from the count fractions obtained from fluorescence X-ray spectra. An example is given for the not-so-favorable system bismuth-germanium-tellurium. On account of the simpler excitation conditions, the same procedures may also be applied to X-ray microprobe analysis.
A Test of the Precision and Sources of Error in Quantitative Analysis of Light, Major Elements in Granitic Rocks by X-Ray Spectrography
Authors: Baird A. K. , MacColl R. S. , McIntyre D. B. 
Published: March 2019

AbstractQuantitative analysis of major elements (Na, Mg, Al, Si, K, Ca, Ti, and Fe) in rocks by classic wet-chemical procedures, in addition to being a costly and laborious process, has been shown to be subject to significant errors. Mineralogists and petrologists, increasingly concerned with determining small elemental differences in rock bodies, have turned to more rapid and precise methods in the field of spectral analysis. The development of X-ray spectrographic techniques in the light-element range has therefore been of particular interest. This paper summarizes the results of a test of the precision and sources of error in the X-ray method as applied to major elements in granitic rocks.The test, using commerically available equipment and the fusion technique of specimen preparation, was designed for a five-way, completely nested variance analysis. Sources of variance are (1) different lengths of fusion time, (2) replications of a single fusion time, (3) replications of briquetting the fused specimens, (4) replications of individual runs in the spectrograph, and (5) replications of individual spectrograph readings of the Kα line intensity. A total of 64 readings per element were obtained and the significance of each factor tested for each element. Greatest sources of error are shown to be in factors 2 and 4. The total variance for each element is expressed as per cent relative deviation of counts per second. Calibration curves of natural and synthetic granitic rocks, fused with dilutions ranging from 13 to 36% rock in borax, provide conversions from relative deviation in counts per second to relative deviation in weight per cent. These values indicate that the precision of the X-ray method is directly comparable with wet chemistry for Si, probably better for Al, and distinctly superior for K, Ca, Ti, and Fe. Of the major rock-forming elements only Na and Mg are presently beyond the scope of the fusion method.
Factors Governing the Structure of Intermetallic Phases
Authors: Laves F. 
Published: March 2019

AbstractA review of the crystal structures of the elements shows some prevailing tendencies of atomic arrangement. These are discussed as space, symmetry, and connection principles. Counteracting temperature and bond factors can be recognized.The same principles and factors are responsible for the formation of alloy structures, taking into account additional factors due to the component's similarities and dissimilarities in size and electronegativity.Similarity favors solid solution and dissimilarity favors compound formation. A q compound is here defined as a phase in a q-component system not connected with any other phase of the system by continuous solid solution. Similarly a q structure is defined as a structure type which needs only q components to be formed (considering present-day knowledge). For example, the binary compound Mg17Al12 has the elementary (1 ™) structure of α-manganese. As a rule, q compounds tend to form p structures with q > p.A discussion of q structures with q = 1, 2, and 3 is given in some detail on the basis of known representatives to show: (1) the competition of geometrical principles and physicochemical factors in determining atomic arrangements of alloys; and (2) the value of rules for making guesses on the probable occurrence of compounds and their chemical composition in polycomponent systems yet unknown.
The Zirconium-Iron System
Authors: Rhines F. N. , Gould R. W. 
Published: March 2019

AbstractBy means of a combined X-ray diffraction and metallographic study, two heretofore unrecognized phases, Zr4Fe and Zr2Fe, have been identified. Approximate verification of this finding has been made by Dr. David Levinson, using microprobe analysis. A tentative revision of the Zr-Fe phase diagram is proposed.
The Effect of Cold-Work on the X-Ray Diffraction Pattern of a Copper-Silicon-Manganese Alloy
Authors: Welch D. O. , Otte H. M. 
Published: March 2019

AbstractPlastic deformation of metals produces a state characterized by the presence of residual elastic strains, small domains which diffract X-rays coherently, and often stacking faults; these effects may be studied with X-ray diffraction techniques. Changes in the lattice parameter, shifts in the relative positions of diffraction lines, and the broadening of diffraction lines were used to study the state of coldwork resulting in Cu-6.6 at.%Si-1.2 at.%Mn after deformation by filing, wiredrawing, and uniaxial tension at room temperature.Both filing and wire-drawing produce large root-mean-square strains and stacking faults, whereas deformation by tension up to 22% extension fails to produce any clear evidence of faulting or root-mean-square strains. Tensile deformation causes fragmentation of coherent domains to an average dimension of 250 Å after 22% extension, and results in a radial, tensile, residual macrostrain arising from a smaller rate of work hardening in the surface layers than in the interior. Wire drawing also results in a residual macrostrain system. Deformation appears to enhance diffusion and promote solute clustering at room temperature.
The Daily Use of a Basic Norelco X-Ray Spectrograph in an Aluminum Reduction Laboratory
Authors: Eastman W. B. 
Published: March 2019

AbstractThree basic methods for the daily use of the X-ray spectrograph are presented with the object of demonstrating simplicity of operation, reliability of results, and ease of use of the basic Norelco X-ray spectrograph by personnel not highly trained in the operation of such equipment. The methods to be outlined briefly are: (1) Determination of calcium fluoride in reduction cell electrolyte; (2) Analysis of cast iron for Si, P, Mn, S; find (3) Analysis of carbon materials for S, K, Ca, V, Mn, Fe, and Ni. The mechanics of the methods will be outlined with the reasons for their selection, and the operating and maintenance problems which have been encountered will be discussed.
Sodium and Magnesium Fluorescence Analysis—Part I: Method
Authors: Henke Burton L. 
Published: March 2019

AbstractAs is well known, the fluorescent yield decreases very rapidly with the atomic number with the result, for example, that sensitive sodium and magnesium analysis is extremely difficult if not impossible with conventional X-ray spectrographs. It is demonstrated, however, that analysis for sodium and magnesium can be accomplished with sensitivity comparable to that conventionally obtained for elements such as aluminum, silicon, and phosphorous, providing that the conditions for excitation and measurement of the associated soft X-radiations are optimized, A high-intensity demountable tube using an aluminum anode has been developed which can be used interchangeably with the conventional spectrographic X-ray source. This provides a large amount of incident radiation, aluminum foil filtered, optimally close in wavelength to that of the line radiation being excited. A gypsum analyzing crystal is used along with greatly reduced beam collimation. The standard flow proportional counter and pulse height discrimination is employed. An appropriate filter, such as aluminum foil, is used as a window for the counter1 to provide further discrimination and enhanced signal-to-background ratio.
The Atomic Order in Guinier-Preston Zones of Aluminum-Silver Alloys
Authors: Gerold Volkmar , Auer Heinz , Merz Winfried 
Published: March 2019

AbstractThe formation of the spherical Guinier—Preston zones in an aluminum-silver alloy is governed by a metastable miscibility gap, which consists of two different sections. The lower section occurs below 170°C (η state), the higher section up to 420°C (∊ state). The zones in the two sections differ in their silver concentration and in their atomic order. To prove the change in order, a combination of X-ray small-angle scattering and electric resistivity measurements was used. As the resistivity depends on the zone size and the atomic order, the change in order can be found when the zone size is known. This size was measured by the X-ray technique. To complete the results, X-rays ingle-crystal diffraction patterns with monochromatic radiation were taken at different stages. According to these patterns, three different states must be distinguished.The η′ state exists at room temperature after quenching from 550°C. The silver atoms prefer a layered arrangement in the zones, which is not very stable. It is destroyed after short annealings above 100°C. The η state is developed during annealing below 170°C. A three-dimensional atomic order is built up with increasing zone size, which results in a marked decrease in the resistivity. For the ∊ state (above 170°C), a nearly random atomic distribution exists. Step-quenching experiments prove that the ordered η state can also be developed at room temperature.
An Explanation of Microstructures in the Tantalum-Carbon System
Authors: Santoro G. , Probst H. B. 
Published: March 2019

AbstractCompositions in the tantalum-carbon system were prepared by carburizing high-purity tantalum wires. The microstructures so produced exhibit regions of a characteristic striated structure identical to those observed by earlier investigators. There are disparities in the literature as to the origin of such structures in the tantalum—carbon system. They have been variously described as “twins,” “striated structure,” “precipitate,” and “structure of unknown origin.” This paper presents conclusive evidence that the structures in question are the result of precipitation on cooling. In addition, a coherent precipitation model is applied in which it is shown that the lattice relationship {0001}Ta2C‖{Klll}TaC can exist with less than 0.5% misfit. This relationship is shown to completely explain the occurrence and characteristic appearance of the observed micro structures. Correlations between chemical analysis, X-ray diffraction results, metallography, and microhardness measurements confirm the proposed precipitation model.
Depth of Saw and Lap Damage in Germanium
Authors: Knudsen John F. 
Published: March 2019

AbstractA study utilizing an application of X-ray diffraction analysis has been made to determine the depth of surface damage in s ingle-crystal wafers of germanium. Damage was introduced by mechanical lapping and sawing. A scintillation-counter double-crystal diffractometer system was used with a 3-m evacuated collitnator. This experimental arrangement employed the (220) reflection, from a silicon monochromator, using Cu Kα1 radiation. All wafers were taken from dislocation-free crystals which were subsequently centerless ground, sawed, lapped, and etched. Half-widths were determined for the sawed and lapped conditions. Successive etchings were used to remove the damaged surface layer with the resulting halfwidths being plotted as a function of thickness removed and etching time.The depths of damage—8.0 ± 0.7 μ for sawing and 3.0 ± 0.7 μ for lapping—were indicated by the depth at which the line breadth measurements reached a limiting value. For crystals used in this study, the median value for this limiting half-width was 28″. The experimental data expressing the rate of etching indicates the presence of two separate rates—one for the damaged material and one for the undamaged substrate. An unexpected finding is a faster etch rate for the undamaged material than that observed for the damaged layer. Quite good correlation is obtained between the depth of damage as determined by X-ray and etching techniques.
Interrelationships of Sample Composition, Backscatter Coefficient, and Target Current Measurement
Authors: Heinrich Kurt F. J. 
Published: March 2019

AbstractThe use of target current measurements in the electron microprobe for quantitative analysis of binary samples has been proposed by several authors. However, the equations proposed for calculations as well as instrumental conditions differ considerably. The present paper relates the target current measurements made with the Applied Research Laboratories microprobe to the backscatter coefficients determined independently. Equations for analyzing binary samples as well as applications to line scans and concentration mapping are given.
A Comparison of the Performance of Gratings and Crystals in the 20-115 Å Region*
Authors: Nicholson James B. , Wittry David B. 
Published: March 2019

AbstractTwo aluminized gratings with different blaze angles, 1° and 7.55′, and a barium stearate monolayer crystal were compared for first-order X-ray line spectra from oxygen (23.707 Å) to beryllium (113 Å). The peak intensities for the gratings were found to be greater than for the monolayer crystal when the same detector, source, and excitation conditions were used. Line-to-background ratios and halfwidths were comparable.
Evaluation of a Demountable X-Ray Tube Vacuum Spectrograph for the Determination of Low-Atomic-Number Elements
Authors: Thatcher John W. , Campbell William J. 
Published: March 2019

AbstractThe fluorescent excitation of long-wavelength X-ray spectra is reviewed with respect to X-ray tube target element, inherent filtration, and optimum kilovoltage. A demountable X-ray tube vacuum spectrograph designed for the determination of the light elements is described. Operation of this instrument with both secondary and combined primary—secondary excitation is evaluated. Examples from the literature are cited to show the feasibility of direct electron excitation of longwavelength spectra.