bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microstuctural Characterization of Water-Rich Boehmite (AlO(OH)): TEM Correlation of Apparently Divergent XRD and TGA Results
Authors: Anovitz LM , Allard LF , Porter W D , Coffey D W , Benezeth P , Palmer DA , Wesolowski DJ 
Published: July 2020

Abstract
An understanding of the solid-phase thermodynamics and aqueous speciation of aluminum is critical to our ability to understand and predict processes in a wide variety of geologic and industrial settings. Boehmite (AlO(OH)) is an important phase in the system Al2O3-H2O that has been the subject of a number of structural and thermodynamic studies since its initial synthesis [1] and discovery in nature [2]. Unfortunately, it has long been recognized that thermogravimetric analysis (TGA) of both synthetic and natural boehmite samples (that appear well crystallized by powder XRD methods) yields significant excess water - typically losing 16-16.5 wt. % on heating as compared with a nominal expected weight loss of 15.0 wt. % [3,4]. The boehmite used in our experiments was synthesized hydrothermally from acid-washed gibbsite (Al(OH)3) at 200°C. Powder XRD and SEM examination showed no evidence of the presence a contaminant phase. The TGA patterns do not suggest that this is due to adsorbed water, so a structural source is likely. We therefore undertook to examine this material by TEM to clarify this phenomenon.
Boehmite is orthorhombic (a = 0.0285nm, b = 0.1224nm and c = 0.0365nm, Amam). The crystals were tabular with major surfaces normal to &lt;010&gt;. Simple powder dispersals onto holey carbon films typically resulted in b-axis orientations parallel to the electron beam. To view other orientations, specimens were mulled in M-Bond epoxy, pressed between plates of single-crystal Si (aligning the boehmite tablets parallel to the Si plates) while the epoxy cured. Electron transparent thin foils normal to the silicon plates were produced by argon ion milling techniques. Sample stability in the electron beam was dramatically improved by cooling to −140°C using an 2 cold stage.
The Time of Pioneers
Authors: Philibert J 
Published: July 2020

Abstract
This paper will cover the history of the first steps of electron probe microanalysis. I was not personally involved with the electron microprobe at the very beginning, although I have been fully involved in the field from 1955. Nevertheless I have interesting information about the heroic times - when, just after the World War, Raimond Castaing was preparing for his doctoral degree.
In January 1947, R. Castaing, graduate in physics, joined the Institute for Aeronautical Research (ONERA), recently created by the French government. In the Materials Science Department, he was very lucky to be endowed with two electron microscopes, very exceptional equipment - a real luxury in 1948. The first one, an American RCA instrument was devoted to metallurgical studies. The second one, build by a French company, was cannibalized by Castaing to produce a fine electron beam to perform point chemical analysis. The idea was suggested to him by Andre Guinier, a famous x-ray crystallographer (Guinier-Preston zones, discovered in 1939) as the best way to solve identification problems in metallography. Castaing was not so enthusiastic about this proposal; the story seemed to him too simple, so simple, he thought, that it was quite surprising that nobody had done it before; but he soon had to face many physical problems that made him understand why many people probably failed, especially lens aberrations that had to be corrected to produce the intense, fine beam of electrons. Another question soon arose about x-ray detection. It was easy to detect the continuous background, but not very informative. Finally Guinier lent Castaing one of his precious quartz crystals (specially cut and ground, of the Johanson type); it was adjusted on a small spectrograph that fitted the outside of the main column (safety rules were in their infancy!). In the first days of 1949, he was able to measure characteristic x-ray emission from a l-μm, 4 nA electron probe. Considering the poor conditions in France after the terrible war, the rapidity with which this result was obtained is quite remarkable.
Microprobe Design in the 1950’s - Some Examples in Europe
Authors: Duncumb P 
Published: July 2020

Abstract
The early days of the electron microprobe were characterized by the variety of designs emerging from different laboratories in Europe, the United States and the USSR. Notable amongst these was that of Castaing in 1954, which employed a magnetic lens in combination with an optical microscope for viewing the sample and positioning the electron probe on the desired point for analysis. The X-ray emission was analysed by two high resolution spectrometers having their axes in the same plane as the electron-optical axis, and with their foci accurately set to coincide with the point of impact of the electron probe. This was a design well suited to point analysis by high resolution X-ray spectroscopy and formed the basis of the first Cameca instrument (Fig 1a).
By contrast, work by Duncumb in the Cavendish Laboratory in Cambridge started with the object of scanning the electron probe over the sample, in order to image the surface in terms of its characteristic X-ray emission. This required a strong lens to give a high current into a finely focused electron probe (Fig. 1b). The first element maps were demonstrated in 1956, and led to the design of Cambridge Instruments’ Microscan, intended as a metallurgical instrument, in conjunction with D.A. Melford of Tube Investments Research Laboratories.
Meanwhile, Long, also in Cambridge, was pioneering applications to mineralogy, and built an instrument for studying conventional slide-mounted rock samples, which could be viewed optically while analysis was in progress (Fig. 1c). This made use of a weaker probe-forming lens, with space for an inclined sample to be viewed in transmitted light. The slim design of the lens allowed it to be partially enclosed in the spectrometer, which received X-rays leaving the sample at a high angle to the surface - a benefit carried through into the Cambridge Geoscan.
Advances in WDS Crystal Performance
Authors: Nielsen C H , Kawabe K , Yamada H , Okumura T , Saito M 
Published: July 2020

Abstract
EPMA....it all starts with Bragg’s Law. It’s all about crystals. WDS crystals are really the rate-limiting step to the usefulness of the EPMA technique. As such they represent the focal point of as much research as any other component of the instrument. There is an inherent need to improve the performance of crystals to assure the survival of the technique. As electron columns permit smaller and smaller spot sizes and as the need to analyze smaller and smaller things increases the search for improved crystals intensifies.
There are generally two crystal parameters that beg for improvement: 1) Energy Resolution and 2) Intensity (especially for light elements). The resolution of crystals is considered adequate for most applications but it’s always useful to have more resolution to better deal with overlapping lines. It’s also becoming useful to measure valence states by observing relative shifts in peak positions. Intensity is the thing that one never gets enough of. It seems that more and more applications demand more intensity. Trace element analysis, particle analysis, heat sensitive sample analysis, light element analysis all scream for more intensity.
Castaing’s Electron Microprobe and its Impact on Materials Science
Authors: Newbury Dale E 
Published: July 2020

Abstract
A central theme of modern materials science has been the exploration of the relationship between the microstructure of a material and its macroscopic properties. Beginning in the late 19th century, the developing field of metallography permitted scientists to view the microstructure of metal alloys. Mechanical polishing followed by selective chemical etching produced differential relief on chemically distinct phases or at grain boundaries. With such specimens, reflection optical microscopy revealed structures with micrometer and even finer dimensions. The microstructural world that was found proved to be highly complex, and most alloys were observed to be chemically differentiated into two or more distinct phases. The answer to many materials science questions required knowledge of the specific composition of such fine scale phases. Castaing’s research was motivated by these considerations, as evidenced by the title of his first paper, “Application of electron probes to metallographic analysis”. The subsequent impact of Castaing’s electron probe microanalyzer (EPMA) has occurred across a broad range of the physical and biological sciences. Materials science has been one of the most active areas and chief beneficiaries, as well as a source of researchers who not only employed electron beam microanalysis to solve their problems but who also contributed innovations that advanced the microprobe field. For example, the abstracts of the First National Conference on Electron Probe Microanalysis contain numerous examples of advanced applications of the electron microprobe to materials science, including analysis of (1) refractory metal coatings (P. Lubllin and W. Sutkowski), (2) diffusion in the Ti-Nb system (D. Nagel and L. Birks), (3) Au-Al alloys (C. Nealey), (4) various steels (H. Nikkei), (5) Al-V-Mo-Ti alloys (R. Olsen), (6) corrosion of Ni-Co alloy (C. Spengler and R. Stickler), and (7) analysis of metal oxides and carbides (T. Ziebold). Integrated over 50 years, the impact of electron probe microanalysis on materials science has been so broad and varied, especially in its continued development and incorporation within scanning electron microscopy and analytical electron microscopy, that a suitably comprehensive review could consume the entire presentation time available for all topics to be covered in this conference! Instead, selected examples of critical applications will be presented to illustrate the impact in materials science.
Quantitative Electron Probe Microanalysis: Fifty Years of Developments in the Application of Castaing’s “Z” and “A” Corrections
Authors: Armstrong John T 
Published: July 2020

Abstract
Castaing, in his remarkable PhD thesis on the electron microprobe, not only detailed the construction of the prototype of what was to be the first commercial electron microprobe and demonstrated its application as a working tool in metallurgy, geochemistry and other materials sciences. In, addition, he also outlined the physical factors involved in the x-ray emission process and developed the general scheme of data correction for quantitative analysis that is still in use today.
In his thesis, Castaing outlined the nature of the processes involved in electron inelastic scattering leading to inner shell ionization and x-ray production (the so-called “stopping power” correction) and the loss of generated x-ray intensity due to elastic scattering of energetic electrons resulting in their emission from the sample (the so-called “backscatter” correction). He showed that the combination of these factors resulted in a correction primarily dependent upon the sample’s average atomic number (the so-called “atomic number” or “Z” correction), which for a thin specimen or one with minimal x-ray absorption and fluorescence would suffice in relating relative intensity to relative concentration. He noted that, in what is known as “Castaing’s first approximation”, the ratio of emitted x-ray intensity of a given line from element “A” in a specimen to that in a standard, KA = IA,spec/IA,std, can be related functionally to the mass concentration of the analyzed element:
Characteristic and Continuum Fluorescence in Electron Beam X-ray Microanalysis
Authors: Nockolds CE 
Published: July 2020

Abstract
Of the different aspects of electron probe microanalysis(EPMA)which were studied by Castaing during his doctorate the work on characteristic x-ray fluorescence was the most definitive. In his thesis, which was completed in 1951, Castaing established the physical and mathematical framework for a correction procedure for fluorescence which is essentially still used in EPMA today. Much of the effort since then has been in refining and improving the accuracy of the correction and extending the scope of the correction to a wider range of specimen types. The Castaing formula was developed for the case of a K x-ray from element A being excited by a K xray from element B (K-K fluorescence) and in 1965 Reed extended the range of the correction by including the K-L, L-L and L-K interactions. In the same paper Reed also introduced the expression from Green and Cosslett for the calculation of K intensities, which was believed to be more accurate than the expression used by Castaing. The original formula included a somewhat unrealistic exponential term to allow for the depth of the production of the primary x-rays and a number of workers have tried replacing this term with a more accurate expression, however, in general this has led to only small changes in the final correction. Reed also simplified the formula in order to make the calculation easier in the days before fast computers; in particular he replaced the jump ratio variable by two constants, one for the K-shell and one for the L-shell. Much later Heinrich showed that this simplification was no longer necessary and that the jump ratio could in fact be calculated directly.
Selecting Standards to Optimize Electron Microprobe Analysis
Authors: Essene EJ , Henderson CE 
Published: July 2020

Abstract
Quantitative analysis with the electron microprobe analyzer (EMPA) has yielded more accurate results over time as a result of improvements in ZAF and other correction routines, mass absorption coefficients, synthetic pseudocrystals for ultralight elements, computers, software programs, backscattered electron (BSE) and energy dispersive (EDS) X-ray detectors. Consequently, many geoscientists view EMPA as routine, and details of procedures, standards, and operating conditions are seldom provided in current publications. However, in overseeing a facility with many users, we have learned that acceptable analytical data are sometimes difficult to obtain even with established analytical procedures and a choice of several hundred standards. After novice users have mastered the routines of sample polishing, cleaning, coating, handling and machine focus, their choice of nonoptimal standards often prevents them from obtaining the most accurate results possible. Optimal analysis for geological problems requires choosing appropriate standards, selection of optimal operating conditions, as well as consideration of the possibility of omitted elements, peak and background overlaps, matrix absorption effects, beam damage and elemental migration, reintegration of heterogeneous materials, fluorescence effects, and variations in the oxidation state of iron.
Minimizing Errors in Electron Microprobe Analysis
Authors: Lifshin Eric 
Published: July 2020

Abstract
Back in the sixties our ability to do both qualitative and quantitative microprobe analysis was often restricted by many factors we now take for granted. Limitations of power supplies, electron optical systems and the mechanical aspects of specimen stages and crystal spectrometers often led to unacceptable drift in both beam position and x-ray intensity measurements. Detector electronics were relatively primitive and phenomena such as pulse distribution shifts with count rate could cause serious errors when pulse height analysis was incorrectly used for noise reduction. The ZAF method, the principal approach for quantitative analysis, was undergoing frequent modification to make it applicable to a broader range of specimens. There were also continuing disputes about which equations to use for a given situation and what experimentally determined constants worked best in the models. Data logging and specimen stage and spectrometer automation were in their infancy and data processing was done on calculators or in batch mode on central computers. Opportunities for errors in data entry abounded.
A Few Examples of Electron Microanalysis of Art Objects at the Boston Museum of Fine Arts
Authors: E. Ogilvie Robert 
Published: July 2020

Abstract
The purpose of this paper is to present a few examples of art objects that have been analyzed with the electron microprobe over the past 40 years at the Boston Museum of Fine Arts. The results of many examinations have led to the fact that the object was a forgery. However, the results of most examinations have proved that the object has the necessary structure and chemistry to be authentic. It should be pointed out, that an object can be proved to be a forgery. But you cannot prove authenticity. The materials used for the object may not fit the time frame for the period, therefore a forgery, or the materials may fit the time period, the structure and style may fit the work of a particular artist or craftsman and still be a copy.
In the early 1960’s a 15th century painting, a Portrait of a Lady, see FIG. 1, was brought to the laboratory at the Boston Museum of Fine Arts for examination.
Electron Probe Microanalysis of Bi-Sr-Ca-Cu Superconductors with Transition Metal Substitutions
Authors: McGee JJ , Obien JM , Wilson RR , Payne JE 
Published: July 2020

Abstract
Electron probe microanalysis (EPMA) is being utilized to characterize the composition of superconductors in the Bi-Sr-Ca-Cu-O system (BSCCO) that are doped with minor amounts of transition metal s. Specifically, the Fe Group (Fe, Ru, Os), the Co Group (Co, Rh, Ir), the Ni Group (Ni, Pd, Pt), the Zn Group (Zn, Cd, Hg), and the other elements in the Cu Group (Ag, Au) can be used as dopants. These first long period ions in their common valence states have similar ionic radii, so only small lattice distortions are expected when other first period ions are substituted for Cu. Our research involves the systematic study of the effect of transition metal substitutions (for Cu) on the properties of the two high temperature superconductors, Bi2Sr2CaCu2O8+δ (2212) and Bi2Sr2Ca2Cu3O10+δ (2223).
Substitution for Cu with transition metal ions enables one to see what effect the changing d and s character of the ions have on the superconducting properties of these compounds.
On the φ(ρz) Curves of Heterogeneous Materials
Authors: Gauvin Raynald , Lifshin Eric 
Published: July 2020

Abstract
Quantitative X-Ray microanalysis is a well established technique for the chemical analysis of homogeneous materials having a flat surface. Precision better than 2% can be routinely obtained if the analysis is performed used the so called ZAF where standards of known composition must be used for all the elements presents in the system under analysis. However, real materials have generally different phases and their composition in a specific phase is not necessary homogeneous. Also, real materials may have surfaces that are not flat and where it is inappropriate to polish them, like a fractured or a corroded surface. It is therefore of paramount importance to develop quantitative schemes for such materials. The first step is to understand the shape of the φ(ρz) curves of heterogeneous materials. This paper present some of these curves that have been obtained with the Monte Carlo program CASINO available for free at www.gme.usherb.ca/casino.
Status Report on Corning Standard Glasses 95IRV, 95IRW, and 95IRX
Authors: Carpenter PK 
Published: July 2020

Abstract
In 1971, Art Chodos and Arden Albee of Caltech contracted Corning Glass Works to produce synthetic glasses containing a number of elements at about 1 weight percent, to be used as electron microprobe trace element standards. Three glasses were produced, 95IRV, 95IRW, and 95IRX (informally known as Corning/Caltech glasses GLV, GLW, and GLX, respectively, in the microanalysis community), which contain the following elements in a Ca-Mg-Al borosilicate glass matrix:
95IRV K Ti Cr Fe Ce Hf
95IRW V Mn Co Cu Cs Ba La Th
95IRX Ni Zn Rb Sr Y Zr Pb U
The source materials for each oxide were weighed-in at 0.80 percent, and each glass was batched in 2 pound lots and drawn into a 0.25 inch cane that was cut into 9 rods of approximately 5 inch length. Initial distribution to end-users was of 1/8 inch slices from the beginning of each cane, as well as sufficient material for chemical analysis to be performed by volunteers. The glass standards were formed in much the same way as the NBS 612, 614, and 616-series trace element glasses, but used a different matrix composition to avoid problems with alkali migration under the electron beam.
Angle-Resolved X-Ray Depth Profiling: Interpretation of Angleresolved Profiles Using a Monte Carlo Approach
Authors: Wilkinson DK , Prutton M , Loveday DA 
Published: July 2020

Abstract
A technique has been developed for the interpretation of composition depth profiles from angleresolved x-ray data using a Monte Carlo electron scattering simulation. Conventional methods for the interpretation of angle-resolved depth profiles used in the fields of x-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) assume that the outgoing signal is exponentially attenuated along its path. This assumption if not valid for angle-resolved x-ray techniques, as the x-ray signal is dependent on both the paths of the incident electrons and the path of the emitted x-rays. In this case, while the latter can be treated using an exponential attenuation, the path of the incident beam is more complex and corresponds to the well known “pear-shaped” interaction volume. In order to reliably interpret angle-resolved depth profiles in which the angle of the incident beam is varied, it is necessary to be able to obtain the distribution of x-ray emission within the sample for any angle of incidence.
Relative Variation of K- And L-Shell Ionization Cross Sections by Electron Impact
Authors: Llovet X , Merlet C , Fernández-Varea JM , Salvat F 
Published: July 2020

Abstract
Knowledge of inner-shell ionization cross sections by electron impact is needed for quantitative procedures in electron probe microanalysis (EPMA) and Auger electron spectroscopy (AES) The common practice is to use semi-empirical formulas, based on the asymptotic limit of the Bethe theory, which sometimes are used beyond their domain of validity. Experimental measurements of ionization cross sections are scarce and affected by considerable uncertainties, thus a mere comparison with experimental data does not permit to draw a definite conclusion abou the accuracy of the various formulas. In this communication, we present new measurements o the relative variation of K- and L-shell ionization cross sections deduced from the counting rate of characteristic x-rays emitted by extremely thin films of Cr, Ni, Cu, Te, Au and Bi bombardec by keV electrons.
The studied films were produced by thermal evaporation on backing self-supported 30 nm carbon films.
Do Ultra-Thin Polymer X-Ray Windows Leak Water Vapor?
Authors: Nielson A , Thorne J 
Published: July 2020

Abstract
Ultra-thin polymer x-ray windows have been developed for energy dispersive spectroscopy (EDS) that enable analysis of the elements lighter in mass than sodium while protecting the detector from light and gases. Windowless detectors produce the ultimate in detector sensitivity, however that sensitivity is lost when ice and other contaminants form on the detector. Polymer windows have had a problem with icing in the past, however modern ultra-thin polymer windows contain metalized layers to prevent the diffusion of water. Nevertheless, over the course of time it has been observed that some detectors with polymer windows that are kept continually cool with liquid nitrogen form a thin layer of ice that attenuates light element sensitivity. The source of this water has been hypothesized to be a gradual leak of water vapor through the polymer x-ray window. This hypothesis has been questioned on the basis that the windows were helium leak tight to 1 x 10−9 mbar L/sec and helium is a smaller molecule than water.