bluuebunny/crossref_metadata_2025 huggingface dataset:
The Lattice Parameters of Iron-Ruthenium Solid-Solution Alloys
Authors: Cotta Leo J. , Gazzara Charles P.
Published: March 2019

The lattice parameters of iron-ruthenium solid-solution alloys of 0.10, 0.20, 0.50, 0.75, 1.50, 2.25, and 3.00 wt, % ruthenium have been determined at 310°K using a Philips back-reflection focusing camera and annealed-powder specimens.
Precision Lattice-Parameter Determination by Double-Scanning Diffractometry
Authors: King H. W. , Vassamillet L. F.
Published: March 2019

The availability of counter-tube diffractometers which can scan both sides of the direct beam makes it possible to locate the zero-angle position by comparing peak positions measured on either side of the beam. These diffractometers may thus be used to determine accurate lattice parameters without the need of a calibrating substance. The feasibility of this method is explored by determining the lattice parameters of pure silver, and the limits of accuracy are discussed.
The Determination of Crystallite Size and Size Distribution from Broadened X-Ray Diffraction Lines
Authors: Quinn H. F. , Cherin P.
Published: March 2019

Magnesium oxide crystallites having mean dimensions in the range of 25–1000 A can be prepared by controlled thermal decomposition of the carbonate.

Following some earlier investigations of Birks and Friedman, we have determined the mean size and size distribution of several such MgO samples from the broadened X-ray diffraction lines which they exhibit. Contrary to the procedure of the above investigators, the harmonic analysis due to Stokes has been used to correct for instrumental broadening and values of mean-size and size-distribution functions obtained from the Fourier coefficients by the methods of Warren and Averbach.

The results obtained are compared with average sizes and distributions obtained by direct examination of the samples in an electron microscope.

A composite sample has been prepared by mixing known quantities of the sample previously studied. The distribution function obtained by harmonic analysis of one diffraction line of the composite sample is compared with the function calculated from the distributions of its components.

Conclusions are drawn concerning the significance of the results obtained by the Warren technique: in particular, the average sizes obtained by this method are compared with those given by the approximate method used by Birks and Friedman.
X-Ray Studies on the Formation of Basic Lead Azides
Authors: Reitzner Bruno , Abel James E.
Published: March 2019

The reaction between solid lead azide and lead oxide at different molar ratios yields two phases of basic lead azide of the type xPb(N3)2·yPbO with different azide content. The first phase was identified as xPb(N3)2·PbO, investigation of the second phase is still under way. The results up to the present time suggest that the formula for this phase is between Pb(N3)2·2PbO and Pb(N3)2·3PbO, probably 2Pb(N3)2·5PbO. The reaction is catalyzed by traces of water. The formulas of the two lead azide phases are established by X-ray analysts. The phases are identical with those found previously when lead azide was thermally decomposed in atmospheres containing water.
Problems in the Temperature Calibration of an X-Ray Diffractometer Furnace*
Authors: Mauer F.A. , Bolz L.H.
Published: March 2019

Tests were carried out with an X-ray diffractometer furnace to determine the temperature variations from point to point in the specimen and the correction to be applied to thermocouple readings. It was found that, under the conditions of the tests, temperature corrections depend on the preparation and properties of the sample. Calibration curves for two standards are given to illustrate this point, and suggestions for improving temperature measurements are made.
Thermal Expansion of Alpha-Alumina
Authors: Campbell William J. , Grain Clark
Published: March 2019

High-temperature X-ray diffractometer measurements by the Bureau showed that alpha-alumina expands anisotropically with expansion parallel to the c axis approximately 10% greater than that parallel to the a axis. Thermal-expansion characteristics of four different alumina samples were determined up to 1200°C; the results are presented in both tabular and graphical form. The combined random and systematic errors in the measurements are considered less than 3% above 500°C and approximately 2% at 1000°C. No differences in expansion were observed between the samples or between the heating and cooling cycles.

Critical evaluation of the literature showed that published values for thermal-expansion coefficients of single crystals vary over a range of 40% (relative values) and disagreement concerning whether expansion of alpha-alumina is isotropic or anisotropic. Systematic and experimental errors were found to be the principal factor for the variation in results, rather than differences in measuring techniques or in samples.

Published values for polycrystalline aggregates also varied. Two laboratories reported values 20–30% lower than those of the Bureau of Mines, but two other laboratories agree with the Bureau within 3–5% above 500°C.
Some Considerations on the Excitation Efficiency in X-Ray Spectrochemical Analysis
Authors: Schreiber H.
Published: March 2019

Most considerations of excitation conditions either have ignored the target material of the X-ray tube and the resulting spectrum of the primary X-ray beam or have dealt with it in very general terms, making a few broad assumptions regarding its effect on the final result. This is quite understandable since any attempt to handle the quantitative relationship between the primary spectrum and the resulting fluorescent spectrum results in extremely complex and unwieldy mathematical expressions. However, with the number of different primary sources now available, it is possible to evaluate these complex expressions in terms of actual data and permit more reliable values to be placed on the relative contributions of the components in the primary spectrum.

A discussion is included of results obtained with X-ray tubes with chromium, molybdenum, tungsten, and platinum targets together with a few typical applications to actual X-ray spectrochemical procedures. Also discussed are the other variables which play a part in the excitation of fluorescent X-ray spectra, such as the primary X-ray tube voltage and the window of the X-ray tube.
The Application of X-Rays to the Analysis of Container Glass
Authors: Laning Stephen H.
Published: March 2019

Container glass, which is derived from the fusion of sand, sodium carbonate, limestone or dolomite, and feldspar, along with small amounts of colorants, reducing agents, and other modifiers, offers quite a challenge to the analyst, whether it be by conventional wet-chemical methods or by modern instrumentation. An analysis for 12 elements, which would take many days by standard wet methods, can now be done in 3–4 hr for a single sample, or 2 hr when analyzed in groups of three or more samples.

X-ray procedures have been developed and calibration curves obtained for SiO2, CaO, MgO, K2O, Al2O3, Cr2O3, Mn2O3, Fe2O3, CoO, BaO,TiO2, SrO, ZrO2, As2O5, and SO3 In glass. With a gravimetric determination of Na2O added to the elements determined by Xray, the total should approach 100%. An analysis Is considered satisfactory if the combined determinations total within ±0.3% of 100%. Various X-ray procedures and matrix effects shall be discussed.
On-Line Type X-Ray Emission Analyzer Systems
Authors: Furbee A.D.
Published: March 2019

This paper describes equipment and performance characteristics of an X-ray emission analyzer designed specifically for continuous, 24-hr on-line process chemical analysis and control. Analysis of elements from Mg (12) upward in the periodic chart are generally feasible.

The basic instrument is a multichannel spectrometer with provision for the simultaneous analysis of up to six elements. Either curved or flat crystals may be used as dictated by the particular application for which it is intended. X-ray detection is accomplished with flow proportional, sealed proportional, and scintillation detectors with both counter tube gas and electronic discrimination against undesired X-rays. The instrument is designed for excellent stability with provision for either automatic or simple manual standardization for long-term drift. A helium atmosphere is used for light elements, and through great care in spectrometer head design consumption is limited to 1 ft3/hr. A number of sample-presenting apparatus have been designed as companions to the basic equipment, including a continuous automatic powder, slurry, and liquid presenter. The powder presenter is particularly adaptable Co continuous analysis of materials which are finely ground (e.g., -200 mesh), whereas the slurry presenter is adaptable to continuous monitoring of solutions or finely ground particles in a slurry state. Readout is available as a d-c signal suitable for strip-chart recorders, voltmeters, data loggers, computers, and control. Digital readout and print out are also available. Performance tests in both the laboratory and field indicate an instrument suitable for on-line process use in a wide variety of industries, including cement, steel, mining, petroleum, and chemicals.
Application of X-Ray Fluorescence Analysis to Process Control
Authors: Bernstein F.
Published: March 2019

The application of X-ray fluorescence-analysis methods to process control is discussed. Various methods of sample preparation are reviewed and compared. The use of the direct sampling technique is discussed and consideration is given to the effects of particle size on precision and accuracy of analytical results. The mechanism of these effects if presented, and some general principles concerning the relationship of fluorescent intensities and particle sizes of pure materials and mixtures are derived. Examples of particle-size effects in cement and mining applications are illustrated.
Electron-Probe X-Ray Spectrograph: Design, Evaluation, and Application
Authors: Brown J. D. , Thatcher J. W. , Campbell W. J.
Published: March 2019

The Bureau of Mines purchased the electron optics, vacuum system, and sample stage assembly for the electron-probe X-ray spectrograph and designed and built the two reflection and two transmission scanning curved-crystal spectrometers. The reflection spectrometers were placed in a vacuum chamber for measurements of long-wavelength X-radiation. Operational characteristics of this spectrograph were determined. A low-alloy stainless-steel sample containing 5 wt. % depleted uranium and a stainless-steel sample containing 20 wt. % gadolinium were analyzed.
Indexing of Powder Diffraction Patterns
Authors: de Wolff P. M.
Published: March 2019

Despite the advances of the electron mtcrodiflraction technique, the determination of unit cells of microcrystalline compounds still depends in many cases on the interpretation of the X-ray powder pattern. The feasibility of this interpretation depends strongly un the precision of the data, the present-day level of which is far from its physical limit. It could be improved by application of monochromators in diflractometry. Some possible methods are discussed. With regard to interpretation, a survey of existing methods is given (Lipson, Ito, de Wolff, Szoldos). Some of these techniques are suitable for computers, at least in the initial phase of the procedure. This is illustrated by application of a zone-finding program for the complete solution of a given pattern. Finally, the influence of impurities and other disturbing factors is discussed.
Helium Path Diffractometry and its Application to Determination of Retained Austenite and Macrostress in Steel
Authors: McCune Robert A.
Published: March 2019

The helium X-ray path has long been used, in spectrography to increase the intensity of the long-wavelength X-rays. The same principle has been applied to diflractometry. Up to threefold intensity increase is observed with chromium Ka radiation with very little increase In background. The peak to background ratio, therefore, is Improved by almost the same factor as the increase in intensity. Application of the technique is illustrated by analysis of gauge block steel for retained austcnite and macrostress.
Precision X-Ray Diffractometry using Powder Specimens*
Authors: Vassamillet L. F. , King H. W.
Published: March 2019

The counter tube diffractometer method for determining d spacings is often rejected for precision work because of lack of information concerning the nature and significance of the inherent errors. Errors concerned with the geometry of the method, the nature of the X-ray source, and the technique of collecting data have all been analyzed previously in some detail. The findings of these analyses, which are scattered throughout the literature, are reviewed briefly. Errors arising from imperfections in the instrument and misalignment of the X-ray source with respect to the diffractometev have been studied experimentally. The results are presented and discussed in terms of the resultant error in the determination of the lattice parameter of a cubic crystal. Errors determined both analytically and empirically are discussed in relation to the extrapolation procedures commonly used for diffractometers. It is shown that, depending on the construction of the instrument, the effect of imperfections in the gears may almost double the error in the final extrapolated value of a lattice parameter.
Oscilloscope Readout of Electron Microprobe Data
Authors: Heinrich Kurt F. J.
Published: March 2019

In view of the amount of data per time unit the scanning electron probe is capable of producing, time economy in data presentation is of great practical importance. In this paper, the characteristics and advantages of various previously known techniques of data presentation are described, and some novel procedures are proposed.
Practical Applications of Filters in X-Ray Spectrography
Authors: Salmon Merlyn L.
Published: March 2019

Applications of filters are routine and useful techniques in X-ray diffraction and.can also be useful in X-ray spectrography to improve analytical results with very simple procedures. Fankuchen demonstrated the use of filters over the window of the X-ray tube to minimize background from the target element and/or elements in other components of the X-ray tube in research programs at the X-ray- Laboratory, Metallurgy Division, Denver Research Institute during the summer of 1952. This general procedure has been adapted to routine analyses by modification of the spectrograph to provide for movement of filters in and out of position between the window of the X-ray tube and the sample while the instrument is in operation. Placement of filters in the X-ray beam path of the spectrograph between the sample and the analyzing crystal is also a useful procedure to reduce interferences by elements exhibiting lines at closely adjacent wavelengths.
Iron Oxide Determination by X-Ray Fluorescence for In-Process Control of Solid Propellant and Premixes
Authors: Lamborn Reuel E. , Sorenson Foster J.
Published: March 2019

Finely divided iron oxide is used as a burning-rate catalyst in several solid rocket propellants. The concentration is critical and must be accurately determined as a quality control point before the propeltant is cast in the motor case and cured, in addition to the iron oxide, the propellant used for ignition of the Air Force Minuteman first stage contains a polymeric binder system, a solid oxidizer, and a metal powder. This composition makes it difficult to determine accurately the iron content by wet methods in the time available daring the propellant processing cycle. The use of X-ray fluorescence has been investigated as a means of satisfying the analysis time requirements while meeting the prescribed accuracy of ±1% of the amount of iron oxide present. Procedures for preparing test specimens have been developed and instrument operation conditions chosen which yield satisfactory precision. When ten specimens from each of three premixes were analyzed for iron content, the observed within-mix mean relative standard deviation was 0.28%; for propellant analyzed under the same conditions, the mean relative standard deviation was 0.35%. Factors affecting mix-to-mix accuracy, such as particle size and shape and interelement absorption and enhancement effects, have been investigated. Accuracy is adequate for in-process control of the iron oxide level in the premix, but further work is required before satisfactory control of propellant is achieved.
A Graphical Solution for X-Ray Powder Diffraction Patterns
Authors: Schieltz N. Cyril
Published: March 2019

A brief and simple reciprocal space equation is derived for the X-ray camera setup, and the theoretical background necessary for graphical solutions is discussed. A typical graphical solution for powder patterns is carried out using the pattern of urea.
A Qualitative X-Ray Examination of the Structure of Fiberglass Under Static Tensile Loading
Authors: Materne H. P.
Published: March 2019

A series of four types of glasses was supplied for investigation. Six individual filaments of each glass (each filament ranged between 7 and 10 μ in diameter) were extracted and the ultimate tensile strength determined for each. The ultimate average tensile strength was then used in the determination of the tensile load applicable to the investigation.

Two methods of examination were used—the Laue and a modified rotation camera. The results of the investigation seem to indicate that a reconstructive transformation in three of the four glasses studied was in process. These results have not been confirmed, due to time limitations. In the case of the E glass investigated, a series of rings were faintly produced after 15 days under 35% of the ultimate average tensile strength. These rings, actually egg-shaped ovals, appeared at 15, 20, and 30 mm from the point of contact of the incident beam. In the other modified E glass and in the YM-31A (BeO) glass, the egg-shaped configuration did not appear in the rotation camera, but did appear in the Laue examination as a semioriented series of spots.
Precipitation of MgF2 in LiF*
Authors: Lilley E. , Newkirk J. B.
Published: March 2019

The structural aspects of the precipitation of MgFa in LiF have been studied in LiF crystals containing up to 3 wt. % MgFs. The precipitate particles appear to be rodlike, having a sawtooth morphology. The rods lie in two directions on matrix planes which are close to but not precisely {111}LIF.

The lattice orientation relationship between MgF2 and LiF has been established by X-ray techniques as

(111)LIF‖(100)MgF2

Laue photographs of slowly cooled crystals show diffuse X-ray scattering effects which are associated with the precipitation process.

Excellent matching of atoms at the interfaces between the precipitate and matrix is postulated on the basis of a hard-sphere atomic model. The results suggest that phase coherency obtains during the early stages of growth, and that growth is controlled by dislocation interfaces.

Rapid quenching retains all MgF2 in solution. Upon subsequent aging a transition structure forms which is based essentially on the LiF lattice but with a cell size of 8.20 Å, roughly double that of LiF. With further aging the transition structure is replaced by the normal MgF2 tetragonal structure.
Oriented Crystallization of Amides on Collagen with Modification of the Collagen Lattice
Authors: Shaw E. H.
Published: March 2019

Rat tail tendons were fixed in 4% formaldehyde at 250 g tension, soaked in nearly saturated solution of the amides involved, and dried while still under tension. X-ray diffraction patterns, taken with rotation around the collagen fiber axis, showed well-defined layer lines of the amide and usually substantial expansion of the collagen equatorial spacing.

The layer lines on collagen, in two cases on abnormal or polymorphic axes, are clustered around the number 4.86 ± 0.33 Å, or a figure twice this, implying the presence of a repeating hydro gen-bond accepting group such as the carbonyl group at this interval. The prominent collagen layer line at 9.4 Å is approximately double this interval.
A Vertically Rotating Double-Crystal X-Ray Spectrometer
Authors: Wittels M. C. , Sherrill F. A. , Kimbrough A. C.
Published: March 2019

A versatile double-crystal X-ray spectrometer has been developed for the precise measurement of X-ray diffraction line widths to tenths of seconds. The device can be employed in either the parallel or antiparallel arrangement for rocking curve studies and can also be used in anomalous X-ray transmission experiments with nearly perfect crystals.

A detailed description of the instrument is given as well as some results concerning the Darwin theory of X-ray diffraction line widths and Borrmann effects.
Beam Stability in the Electron Probe Microanalyzer
Authors: Fitzgerald Ray
Published: March 2019

The reliability and speed at which an analysis can be completed, using methods of the electron probe microanalyzer, depends to a large extent on the stability of the electron beam. The incident electron energy and total incident current must be maintained within prescribed limits to ensure accurate and reproducible X-ray data. The incident electron probe diameter must also stay within prescribed limits for maximum resolution over the analysis time. The performance of the electron optics is discussed in relation to high-voltage supply, current regulators, and filament supply. Methods for probe current stabilization using aperture sensing are discussed.
Double-Scanning Diffractometry in the Back-Reflection Region
Authors: King Hubert W. , Russell Carolyn M.
Published: March 2019

A scanning range over Bragg angles from −163 to +163° 2θ is obtained by combining a diffractometer capable of scanning both sides of the primary X-ray beam with a very short (3-in.) high-power focused X-ray tube. The ability to scan the included angle 4θ between respective diffraction profiles on either side of the primary beam over the entire range of Bragg angles, provides a direct method of eliminating errors caused by a displacement of the specimen surface from the axis of the goniometer. The method is demonstrated by determining the lattice parameters of standard specimens used in the I.U.Cr. Precision Lattice Parameter Project.
Determination of Lattice Constants of Polycrystalline (Monoclinic) Uranium Tetrafluoride*
Authors: Morris Peter R. , Morton Vernon
Published: March 2019

A technique is described for determining lattice constants of polycrystalline monoclinic materials and partition of observed experimental error among the several constants. The technique is illustrated for uranium tetrafluoride. Precision of the method is typically ±0.01 to ±0.02 Å on the unit cell lengths, and ±4 to ±8 min on the angle between axes. This is of the order expected, were single-crystal techniques limited to the range of Bragg angles available.
X-Ray Diffractometry of Polymers by a Transmission Method
Authors: Wilchinsky Zigmond W.
Published: March 2019

The practicability of using a symmetrical transmission method for accurate measurement of line positions and intensities for polymer samples was investigated. In comparison with the conventional symmetrical reflection method, the transmission method has some inherent advantages in the measurement of line positions. Very little extraneous line asymmetry is introduced by transmission, and errors due to sample misalignment can usually be corrected empirically. On the other hand, the reflection method introduces noticeable line asymmetry and a shift of the center of intensity toward smaller 2θ. Also, errors due to sample misalignment may be difficult to correct. Intensity measurements can usually be made with about the same accuracy by either method. However, the transmission method is less sensitive to misalignment errors, especially at the lower diffraction angles.
An Automated System for Extended X-Ray Absorption Measurements
Authors: Christofferson G. D. , Hughes T. R. , Klaver R. F.
Published: March 2019

In the study of X-ray absorption fine structure, one is faced with the task of measuring sample absorbance over an extended wavelength region. For the sake of accuracy, these measurements are often carried out on a fixed-count basis. Manual collection of the data at a hundred or more spectrometer settings is a tedious and time-consuming chore. This paper describes an automated system for accumulating absorption data.

The equipment is used in conjunction with a Philips wide-range goniometer employed as a single-crystal spectrometer. It consists of: (1) a four-position sample changer, (2) a fixed-count selector for each sample position, (3) a five-digit counter and paper tape printer which register and record sample identification and counting times based on a 60-cps clock frequency, and (4) a programmer. The spectrometer advance is accomplished using the Philips step-scan arrangement. An IBM 7094 FORTRAN program for data reduction and computation will be described. The possibility of using X-ray absorption fine-structure measurements as a quantitative method for determining the various absorbing species will be discussed.
Light Element Analysis with an Electron Microprobe
Authors: Ong Poen Sing
Published: March 2019

In the microprobe, lead stearate decanoate multilayer analyzers have proven to be practical components for X-ray spectrochemical analysis of the light elements. Better controlled techniques in the deposition of the layers have already produced analyzers yielding improved peak to background ratios as well as higher counting rates. Operational techniques, optimizing instrumental performance, will be discussed. Analytical data on the elements fluorine through boron, obtained with a modified commercial microprobe, will be presented.
Variation of X-Ray Spectral Line Position with Ambient-Temperature Change: A Source of Error in X-Ray Spectrography
Authors: Lee Frederick S. , Campbell William J.
Published: March 2019

The effect of temperature change on LiF, ADP, and EDDT analyzing crystals was studied by measuring the change In intensity of a selected X-ray spectral line while maintaining a constant 2θ position on the spectrometer. A change in interplanar spacing due to thermal expansion and contraction satisfactorily account for experimentally observed line shifts for LiF and ADP. EDDT showed a large unexplained decrease in reflectivity with increasing ambient temperature.

An equation was developed to express the change in intensity at a constant 2θ position as an exponential function of temperature. In this equation the thermal expansion coefficients of the principal axes of the crystal, the width of the spectral line at half-height, and the Bragg angle appear as factors. Intensity changes due to peak shift were tabulated for LiF, ADP, NaCl, silicon, germanium, quartz, calcite, fiuorite, and topaz.
X-Ray Study of Wire-Drawn Niobium and Tantalum
Authors: Adler R. P. I. , Otte H. M.
Published: March 2019

Deformation, introduced into niobium and tantalum specimens by wire drawing at room temperature, produced changes in the shape and position of X-ray diffraction peaks. The resultant peak profiles and locations of all available peaks were recorded using the Debye-Scherrer geometry on a modified dtffractometer with crystal monochromated Cu Kα radiation. The amount of deformation in the surface layers of both metals was found to saturate essentially after only 20% reduction in area. The measured decrease in the lattice parameters of either material was attributed to a residual surface stress; the average value for the deformed saturated state for both tantalum and niobium wires corresponded to an equivalent longitudinal tensile stress of 35 ± 5 kg/mm2. Integral breadth measurements revealed approximately equal X-ray particle sizes in the <100> and <110> directions; the minimum particle size for the micro structures of both metals was around 200 Å and occurred after the first few draws.
Oriented Crystallization of Urea in Membranes
Authors: Shaw Edwin H.
Published: March 2019

Inner egg shell membrane was soaked in 2 M urea solution and dried. CuKαX-rays directed perpendular to the membrane yielded an urtsymmetrical diffraction pattern with urea 110, 111, 102, 210 and 211 planes diffracting to the right and urea 101, 200 and 201 planes diffracting to the left. The urea appears to be hydrogenbonded diagonally between the lamellae of β-keratin at an angle of 33.5° to the 6.68 Å b-axis (fiber axis) of the parallel pleated sheet structure, shortening the half-axis lengths in the a direction from 4.73 Å to 4.41 Å. Similar results were obtained with formalinized dog mesentery. Keratinous outer egg shell membrane, formal in bed collagenous dog renal capsule, formslinized collagenous pheasant pericardium, and formalinized callogenous human arachnoid yielded symmetrically oriented urea layer lines. Formalinized dog renal fascia and pleura yielded random urea lines.
Plane-Polarized, Two-Crystal X-Ray Spectrometer
Authors: Donahue Raymond J. , Azároff Leonid V.
Published: March 2019

A two-crystal spectrometer employing a Cole polarizer made from a germanium crystal as one of the crystals is described. Experimental tests show that placing the polarizer crystal in the second position markedly improves the degree of plane polarisation, in full agreement with the predictions of the dynamical theory of X-ray diffraction. Tests indicate that the twice-diffracted beam h better than 95% plane polarized. The angular resolving power of the instrument is comparable to that of conventional two-crystal spectrometers. The almost wholly planepolarized monochromatic X-radiation, moreover, permits certain tests to be carried out far more effectively than is possible with partly polarized X-ray beams.
The Application of the Ziebold Correction Procedure for Probe Data to Three Ternary Copper-Base Alloys
Authors: Ingersoll Richard M. , Taylor Jack E. , Derouin Donald H.
Published: March 2019

For the quantitative analysis of a 65 Cu-30 Ni-S Fe alloy, a 96 Cu-3 Si-1 Mn alloy, and a 78 Cu-20 Zn-2 Al alloy, the Ziebold empirical method of correcting electron-microbeam-probe data was used. Four binary standards, of single-phase Cu-Ni, Ni-Fe, Cu-Mn, and Cu-Zn alloys, were cast and the a correction factor found for each element in each binary by Ziebold's relationship (1 – K)/K – α (1 – C)/C, where K – I/I0 found in the probe and C is the weight fraction found by wet chemistry. The ARL EMX probe was used at 30 kV with a 25-μ beam diameter to negate inhomogeneities. Experience with these binaries indicated that in the presence of secondary fluorescence, the experimental α values agreed poorly with theoretically calculated K values; however, where secondary fluorescence was negligible, agreement between the experimental and theoretical α values was good. The α values for Cu–Si, Cu–Al, Al-Zn, and Mn–Si alioys, were therefore calculated from the theoretical equations. The α values for Cu–Fe alloys were also calculated from theoretical considerations because single-phase binaries over the composition range of interest could not be made for this system. All these α values were used in Ziebold's ternary equations to correct probe data (again using a 25-μ beam) from specimens of Cu–Ni-Fe, Cu–Si–Mn, and Cu-Zn–Al. These results were compared to wet-chemistry analyses for the same specimens with quite good correlation between the two sets of data. Calibration curves for the binary systems Cu-Ni, Cu-Fe, Ni-Fe, Cu-Mn, Cu-Si, Mn-Si, Cu-Al, Cu-Zn, and Al-Zn were made and are reproduced.
L and M X-Ray Spectra in the Region 2-85 Å
Authors: Davidson Franklin D. , Wyckoff Ralph W. G.
Published: March 2019

A detailed study has been made of the intensities of the L, M, and N X-ray spectra for wavelengths in the region from 2-85 Å. Some of the lines of these spectra involve energy levels which are gradually being depopulated with decrease in atomic number, and this leads to a progressive simplification of the spectra as the wavelength increases. Spectra have also been obtained from several compounds involving these elements in different valence states. Differences in relative intensities have been observed for these compounds, but because of a lack of accurate information about absorption, it is impossible as yet to give such results an adequate interpretation.
Application of Multilayer Analyzers to 15-150 Å Fluorescence Spectroscopy for Chemical and Valence Band Analysis
Authors: Henke Burton L.
Published: March 2019

Methods and instruments have been developed for efficient spectroscopic analysis in the 15 to 150 Å ultrasoft X-ray legion using specially designed Langmuir-Blodgett type multilayer analyzers with a flow proportional counter detection system. Simple adaptations of the basic Philips vacuum spectrograph are employed with a high-intensity, demountable, ultrasoft X-ray source to excite fluorescence in the lighter elements for chemical and valence band analysis.
Some New Methods of Precision X-Ray Spectrometry
Authors: Das Gupta K. , Welch Herbert , Gott P.F. , Priest John F. , Cheng Sunny , Chu Edmond
Published: March 2019

Three novel methods of x-ray spectrometry have been developed in recent years at Texas Tech University. These are:

1. Three crystal spectrometer

2. Two curved crystal spectrometer

3. Spherically bent crystal spectrometer.

In this paper the new design features, and experimental results will be discussed to indicate the usefulness of the new instruments. The three crystal spectrometer is a modified two crystal instrument. A third crystal is used to analyze the output of the two crystal spectrometer. The first two crystals are operated as a standard two crystal spectrometer. The third crystal is swept through the spectrum transmitted by the first two crystals for each setting of the first two crystals. The peak intensity of the third crystal sweep corresponds to the energy setting of the two crystal spectrometer, and is the intensity used to plot the spectral lines. The two curved crystal spectrometer utilizes two transmission spectrographs with radii having a 2:1 ratio in series, the crystal with the smaller radius being set so that its focal point falls on the Rowland circle of the larger radius crystal, This instrument has a very low background intensity and is suitable for precision scattering and diffraetion work. The spherically bent crystal spectrometer makes use of high light gathering power and high orders of reflection to allow high resolution studies of weak spectral lines. It also has the advantage of ease of alignment and operation.
“Automation of a Manual Spectrometer by use of a Hardwired Angle Programmer and Microcomputer”
Authors: Croke J. F. , Jenkins R.
Published: March 2019

The manual X-ray spectrometer, PW-1410, has been upgraded to a level of automatic operation through the addition of a hardwired Angle Mode Programmer, a Motor Controller and by interfacing a dedicated microcomputer. It is the purpose of this communication to describe the system together with data reduction software developed for the microcomputer. This paper will also discuss quantitative analysis techniques using matrix mass absorption coefficients measured with a new absorption cell attachment.
The Effect Of Self-Irradiation on the Lattice of 238(80%)PuO2. II
Authors: Roof R. B.
Published: March 2019

The results of the third year of observations on the effects of self-irradiation on the lattice of 238(80%)PuO2 indicate a small but definite trend toward a reduction in the lattice parameter of this material. The lattice parameter increased from 5.41408±6 Å at 5 weeks to 5.41636±38 at 114 weeks and then decreased to 5.41364±23 at 157 weeks after the start of the experiment. A similar trend is noted in the half-widths of the diffraction lines. For the 622 reflection the half-width increased from 0.283±14°20 at 5 weeks to 0.711±90 at 114 weeks and then decreased to 0.660±89 at 157 weeks.
Measuring Techniques of Parallel Beam-Diffraction Micrography
Authors: Barth H.
Published: March 2019

Examination of the substructure of crystalline solids by diffractographic methods has recently developed into an independent field of work alongside atomicstructure analysis. Diffraction micrography with electrons is characterized by the small size of the distortion fields and the high resolving power in small crystal ranges (1000-3000Å thickness). X-ray diffraction micrography is characterized by great reciprocation between wave field and distortion field and by undisturbed preparation and undisturbed testing in the large crystal ranges (up to 15 cm2). There are two groups of examination methods for diffraction micrography with X-rays: (1) Examination with a finely limited, polychromatic or monochromatic X-ray source and moving sample, according to A. R. Lang et al. (2) Examination with a parallel-ray beam of polychromatic or monochromatic X-rays with fixed sample, in accordance with Berg-Barrett et al. For the examination of coarse defects in single-crystalline and poly crystalline matter, the parallel-beam method offers a wide scope for studies in the physics and applications of single-crystal line and polycrystalline solids. This paper therefore includes a summary of the methods using collimation systems and grating diaphragms. Measuring techniques and results are illustrated with the help of reflection and transmission pictures on various crystals. The various methods and refined measuring technique of the parallel-beam method enable the following to be defined: (1) Localization of crystallites from 20 μ diam. upward in a surface up to 15 cm2. (2) Determination of the faces of averted crystallites from 20 µ diam. upward in crystal surfaces. (3) Angle of avertence of crystallites or curvature angles of net faces from 1 to 3° in crystal surfaces up to 15 cm2. (4) Subangle grain boundaries, slip bands, and dislocation lines; also distortion fields (from 20 μ upward) resulting from mechanical, thermal, and radiation damage.
X-Ray Diffraction Microscopy of Planar Diffused Junction Structures
Authors: Howard J. K. , Schwuttke G. H.
Published: March 2019

Basic processing steps utilized in the fabrication of planar silicon devices include (a) substrate preparation, (b) epitaxial deposition, (c) thermal gvowth of silicon dioxide over the entire silicon wafer surface, (d) device pattern formation by photoetching techniques, and (e) diffusion of n-type or p-type elements through the holes to produce localized regions of desired conductivity, A detailed study of the various diffraction phenomena associated with such structures is presented. X-ray topographs of planar transistors show distinct contrast features such as excess diffraction intensity along the silicon oxide/silicon boundary and/or excess diffraction intensity inside the device area. The diffraction phenomena are discussed in terms of reversible elastic deformations, frozen-in lattice deformations, strain fields and imperfections generated by the various processing steps. A technique is presented to measure the sign of the elastic deformations. The phenomenon of stressjumping across semiconductors interfaces is described, and finally the implications of stress-strain relations on junction performance are stated.
Multilayer Soap Film Structures*
Authors: Ehlert R. C. , Mattson R. A.
Published: March 2019

Multilayer soap film structures, particularly the lead stearate variety have been used for several years as a dispersing element in soft X-ray spectrometers. These structures have a high scattering power, and if a high order of diffraction is used for the shorter wavelengths they provide good resolution throughout the 10-80 Å range. Structures having a 2d spacing smaller than that of lead stearate (100 Å) would provide greater dispersion and, hence, resolution in the first order for radiation in the 10-40 Å range. Details concerning the conditions required to build multilayer structures from the soaps of shorter fatty acids such as lead myristate, lead laurate, lead caprate, etc. are given. The various members of the soap film family are compared regarding their diffracting power both as a function of wavelength and the order of diffraction. Information is given regarding the dependence of the diffracting power, the width of the diffraction peak at half maximum and the peak to background ratio as a function of the number of double layers in a structure. The absorption occurring within a lead stearate and a lead laurate structure has been experimentally measured. Observed spectra can, thus, be corrected for the filtration caused by the soap film structure. The soap film family is evaluated as a dispersing element by comparing the various Structures with single crystals such as EDDT and KAP.
Production Efficiencies of X-Ray Emission Spectra by Proton Bombardment
Authors: Sterk A. A. , Marks C. L. , Saylor W. P.
Published: March 2019

Production efficiencies for the excitation of characteristic soft X-ray emission spectra by proton bombardment were investigated. Results were obtained for K-, L-, and M-shell lines of various elements as a function of proton energies ranging up to 100 keV.

For comparison putposes, helium, nitrogen, and argon ions also were accelerated and used as bombarding particles to yield efficiency data for some of the same spectral lines.

The data demonstrate that:

1.

The production efficiencies of spectral lines excited by protons are, in the first approximation, dependent on wavelength only and are independent of the atomic shell with which they are associated.

2.

Production efficiencies increase with the atomic weight of the bombarding ions for some of the spectral lines investigated.

X-ray generation by proton bombardment is a powerful method for producing high-intensity monochromatic radiation for wavelengths above approximately 10 Å, The same technique can be used for analytical purposes to determine the concentration of low atomic number elements.
Preparation of Electron Probe Microanalyzer Standards using a Rapid Quench Method
Authors: Goldstein J. I. , Majeske F. J. , Yakowitz H.
Published: March 2019

Standards for microprobe analysis can be made to serve two purposes: (a) proposed correction models can be tested with them, and (b) analysis can be performed more accurately in the system which includes the standard. Few microprobe standards presently are available because they must be homogeneous on the micron scale and their composition must be known accurately. A modified Duwez splat cooling method is described which enables the investigator to prepare suitable standards in most cases. The apparatus which is relatively simple and inexpensive is described in detail. The systems Au-Si and Al-Mg were chosen as test cases. Suitable standards were prepared at different concentrations in each system. The analytical results for all compositions in Al-Mg are presented and discussed.
The Demountable Tube in Light Element Fluorescence Analysis
Authors: Short M. A. , Ruscoe M. J. H.
Published: March 2019

In view of the importance of obtaining optimum conditions for the X-ray fluorescence analysis of light elements, an investigation has been made of the effects of varying the X-ray tube target, the target take-off angle, the tube voltage, and the tube window thickness. The effects of these parameters have been observed by measurement of the intensity of fluorescence of two light elements using the Ray max 60 demountable tube and vacuum path spectrometer. The results obtained are compared with those given by theoretical calculations based on consideration of the relevant parameters; good qualitative agreement has been obtained. It is shown that a high primary X-ray intensity is obtained with a high target take-off angle, a low angle of incidence of the electron beam on the target, and an optimum setting of tube voltage. It is further shown that the most suitable target to use for the fluorescence analysis of light elements is markedly dependent on the thickness of the X-ray tube window.
Total Nondestructive Analysis of Caas Syenite
Authors: Volborth A. , Fabbi B. P. , Vincent H. A.
Published: March 2019

Determination of 35 trace and 8 major elements in a granitic rock by nondestructive X-ray emission and fast-neutron activation methods has been accomplished. Trace elements arsenic, barium, cadmium, cerium, cobalt, chromium, cesium, copper, gallium, gadolinium, germanium, hafnium, mercury, indium, lanthanum, molybdenum, manganese, niobium, neodymium, nickel, rubidium, antimony, scandium, samarium, tin, strontium, tantalum, thorium, titanium, vanadium, yttrium, ytterbium, zinc, and zirconium and major elements aluminum, calcium, iron, potassium, and silicon have been estimated in the vacuum X-ray spectrograph. Phosphorus has been excited by a chromium-target tube. Major elements magnesium, sodium, and oxygen have been estimated by the Henke aluminumtarget X-ray spectrograph. Major elements oxygen and silicon have also been determined by fast-neutron activation. Detection limits for traces are in cur system in the range of 1 to 100 ppm with standard deviations of about 1 to 10 ppm. Precision in the determination of major constituents is better than 1% in relative standard deviation. The data are reported in parts per million for the trace elements and for the major elements as well. It is suggested that this type of repotting of geochemical data be preferred to the conventional reporting of major constituents as oxides.
X-Ray Fluorescence of Suspended Particles in a Liquid Hydrocarbon
Authors: Gunn E. L.
Published: March 2019

In the application of X-ray fluorescence to the inspection of petroleum or petrochemical products, the measured element may not be ideally dispersed in the organic substrate but may exist as suspended particles. A question naturally arising is how small the particles must be to approximate the fluorescent intensity level of the true solution. The fluorescent emissions of suspensions of particles in a viscous hydrocarbon were measured and the intensities compared with true solutions of zinc, iron, and silicon, respectively. Particle segregates were classified by raicrosieve and photomiorographic inspection. Iron or zinc particles of 8-μ size yield 65% of the intensity of the solution state. Increase of particle size to 70 μ reduces intensity by several fold. Silicon, dispersed as porous silicon dioxide particles of 28-μ size, yields 80% of the intensity of the solution form. Reliable measurement of a suspension can be made provided it is stable and a standard closely simulating it is available for reference or if proper intensity corrections are applied for a known particle size in suspension. Comparisonsof experiment with theory for the particle size-intensity effect agree only moderately well. This is attributed to uncertainties in the parameters relating the two. Theory indicates that zinc or iron in suspended form should be less than 1 μ in size to approximate the intensity of the elements in solution. Additional research aspects of particles in suspension are suggested.
Rare-Earth Analyses by X-Ray-Excited Optical Fluorescence
Authors: Burke W. E. , Wood D. L.
Published: March 2019

X-ray excitation causes rare-earth impurities in yttrium oxide and gadolinium oxide to emit intense and highly characteristic optical line fluorescence, which enables their analyses at low concentrations. The limits of detection for praseodymium, ncodymium, samarium, europium, gadolinium, terbium, dysprosium. holmium, erbium, thulium, and ytterbium in these two oxides range from 1 to 100 parts per billion (ppb). In other rare-earth oxides which have been investigated. the fluorescent intensities arc greatly reduced. Successful analyses can be made only by dilution in high-purity Y2O3. This dilution raises the detection limits for rare earths in these other oxides to the part per million range. X-rays from the chromium target of a cual-target X-ray tube are about two times more efficient in exciting rareeaith optical fluorescence than are the tungsten-target X-rays, even though the total energy output of the chromium target is only about one-third that of the tungsten target. With either target material, the rare-earth intensities vary linearly with the X-ray tube current, but a plot of intensity versus the square of the accelerating potential is not linear; it drops off at higher voltages.