bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular imaging by Raman microscopy
Authors: Batchelder D.N. , Smith B.J.E. , Webster S. , Cheng C. 
Published: June 2020

The optical microscope relies on spatial variations of refractive index, absorption and reflectivity in a specimen in order to produce the modulation in light intensity necessary to form the magnified image. The ability to identify the materials which comprise the specimen is very limited as these properties are generally not material specific. By contrast the Raman spectrum of a material is usually not only sufficient to give positive identification, but detail in the spectrum can often be used to assess the physical state of the material. Thus images recorded in light scattered in a particular Raman band should be very informative about the distribution of different molecular species.We have developed a Raman microscope which uses multilayer dielectric filters to select the Raman band with which the image is formed. The optical quality of the filters is sufficiently high so as not to degrade the image forming capabilities of the microscope. The filters typically have a pass band of 20 cm-1 and are wavelength tuned by rotation.
Use of a Gram-Schmidt response function in infrared microspectroscopic imaging
Authors: Carl Richard T. , Weesner Forrest J. 
Published: June 2020

The technique of infrared microspectroscopic imaging has found application in a variety of fields including coating technology, semiconductor manufacturing, and polymer science. The typical infrared microspectroscopic imaging experiment consists of collection of a four dimensional array of data (X, Y, frequency, intensity) followed by data reduction. In previous reports, this data reduction to three dimensions has been performed by monitoring the intensity or peak area of a specific frequency in the final transformed spectrum. This technique has been referred to as Functional Group Imaging (FGI).This paper reports on the application of an interferograms based data reduction routine to infrared microspectroscopic imaging. The Gram-Schmidt (GS) orthogonalization procedure, popularized in application to GC-IR data, was used to measure the infrared response across the surface of the samples. The details of the vector algebra used in the GS calculations may be found elsewhere. Briefly, a set of interferogram segments is selected to form an orthonormalized basis set describing background conditions.
The examination of glass surfaces using time of flight mass spectrometries
Authors: Evans B. , Farnworth M. A. , Johnson A. E. 
Published: June 2020

The surface composition of glass has a substantial impact on its end use, being a key factor in coating adherence, durability, and product life time. There is a continuing need to provide information on the precise composition of the exterior surface and to examine how this varies with time and exposure to weathering conditions.The influence of water on the surface composition is of critical importance and of the techniques available to examine the surface, secondary ion mass spectroscopy has a range of advantages because of its high sensitivity and its ability to monitor Hydrogen in addition to all the other elements. It can also provide information on the presence of specific organic molecules on the surface.Early work by Surman and Vickerman established that the preferred method of examining glasses in static SIMS was by means of a fast atom beam since this reduces the problems of charging associated with insulating surfaces and that reasonable quantification could be obtained if suitable standards were used.
X-ray microanalysis of frozen plant cells and tissues
Authors: Boekestein Abraham , Clerkx Anke C.M. , Verkerke Ruud , Ammann Norbert , Baayen Robert P. 
Published: June 2020

The determination of concentrations of relatively freely diffusable ions in localized compartments of botanical tissues has become an essential technique in plant physiology . In order to analyze approximately the in vivo elemental concentrations, the scanning electron microscope has been adapted to facilitate the observation of frozen-fractured botanical cross-sections, thus enabling electronprobe X-ray microanalysis of the exposed surface. Although the analysis technique seems to have come in its productive years, it still has a number of unsolved problems, which are both related to the preparation of frozen-hydrated specimens and to the analysis method itself.The most important problem in quantitative X-ray microanalysis of frozen-hydrated biological specimens, is the avoidance of ice crystallization artefacts. This phenomenon is rather critical in botanical tissue preparation because plant cells are relatively big and almost entirely occupied by a central vacuole. In this situation ice crystals can grow to large dimensions and disturb the originally homogeneous ion content.
Ion microprobe imaging of biological samples
Authors: Slodzian Georges 
Published: June 2020

Microanalysis of biological samples by using secondary ion emission is a challenging problem because it requires high lateral resolving power, high sensitivity and high selectivity simultaneously. In this paper, the limits and the possibilities of the method will be examined regardless of the sample preparation conditions that is from a simple instrumentalist's point of view.Any mass spectrometric method is destructive which means here that a given volume of the sample has to be sputtered to produce an adequate secondary ion signal. The size of this volume depends upon the atomic concentrations, the atomic density, the useful yield and the magnitude of the desired signal. To take an example, with an useful yield of 1% it would be necessary to sputter 300 atoms M to get an average signal of 3 ions (±) related to M. Such a signal would allow to detect the presence of element M with about 95% certainty (probability of getting one ion at least).
How SIMS microscopy can be used in medicine
Authors: Fragu Philippe 
Published: June 2020

The identification, localization and quantification of intracellular chemical elements is an area of scientific endeavour which has not ceased to develop over the past 30 years. Secondary Ion Mass Spectrometry (SIMS) microscopy is widely used for elemental localization problems in geochemistry, metallurgy and electronics. Although the first commercial instruments were available in 1968, biological applications have been gradual as investigators have systematically examined the potential source of artefacts inherent in the method and sought to develop strategies for the analysis of soft biological material with a lateral resolution equivalent to that of the light microscope. In 1992, the prospects offered by this technique are even more encouraging as prototypes of new ion probes appear capable of achieving the ultimate goal, namely the quantitative analysis of micron and submicron regions. The purpose of this review is to underline the requirements for biomedical applications of SIMS microscopy.Sample preparation methodology should preserve both the structural and the chemical integrity of the tissue.
Application of quantitative microscopy to specialty metals
Authors: Vander Voort George F. 
Published: June 2020

Quantitative microscopy methods have been utilized for the characterization of specialty metal microstructures for many years. Initially, most work was more qualitative than quantitative because all methods were manual. However, since the introduction of more capable image analyzers in the 1980s, with vastly improved computer software and hardware, automated techniques have gained favor. With the implementation of automated image analysis equipment, users have quickly realized that specimen preparation techniques must be improved and also automated. The primary applications of quantitative microscopy methods in the specialty steel industry are: inclusion ratings, grain size measurement, volume fraction determination, and carbide distribution studies.The American Society for Testing and Materials (ASTM) has been a leader in the development of microscopical test methods, chiefly through Committee E-4 on Metallography, which recently celebrated its 75th anniversary. Other technical societies, companies, organizations in other countries, and international organizations have also made notable contributions. ASTM standards are developed by volunteers from industry (both producers and purchasers), equipment manufacturers and academia using a consensus approach requiring voting at three levels.
Quantitative electron probe microanalysis of lithium-aluminum-borate glasses: a feasibility study
Authors: Marinenko Ryna B. 
Published: June 2020

During the last few years both the instrumentation and data reduction procedures for analysis of low atomic number elements have substantially improved. For WDS analysis, synthetic multilayered crystals (LDE) designed specifically for the detection of low atomic number elements have surpassed the performance of the stearate and MYR crystals, showing much enhanced peak-tobackground ratios for boron, carbon, oxygen, and nitrogen. In addition, the cost of computers and computer memory has been reduced significantly, thus enabling scientists in our field to reevaluate conventional data reduction procedures for quantitative analysis. Assumptions and approximations can now be replaced in computer programs by the complete calculation and/or data base. A number of improved approaches to quantitation have resulted as well as a new interest in quantitating the low atomic number elements. Excellent results have been achieved by Bastin, Pouchou and Pichoir, Armstrong, and others.In 1984 a group of Standard Reference Materials (SRM's) called Glasses for Microchemical Analysis were issued by the National Bureau of Standards, NBS(now the National Institute for Standards and Technology, NIST).
An improved interference correction for trace element analysis
Authors: Donovan John J. , Snyder Donald A. , Rivers Mark L. 
Published: June 2020

We present a simple expression for the quantitative treatment of interference corrections in x-ray analysis. WDS electron probe analysis of standard reference materials illustrate the success of the technique.For the analytical line of wavelength λ of any element A which lies near or on any characteristic line of another element B, the observed x-ray counts at We use to denote x-ray counts excited by element i in matrix j (u=unknown; s=analytical standard; ŝ=interference standard) at the wavelength of the analytical line of A, λA (Fig. 1). Quantitative analysis of A requires an accurate estimate of These counts can be estimated from the ZAF calculated concentration of B in the unknown C,Bu measured counts at λA in an interference standard of known concentration of B (and containing no A), and ZAF correction parameters for the matrices of both the unknown and the interference standard at It can be shown that:
Energy-Loss functions of Au derived by Monte Carlo analysis of angle-resolved Reels spectra
Authors: Yoshikawa Hideki , Shimizu Ryuichi 
Published: June 2020

It is very well understood for free electron like metals that photoelectrons undergo not only bulk excitation but also surface excitation. For transition metals the contribution of surface excitation has not yet fully been discussed, and optical loss function has been widely used for background analysis of x-ray photoelectron spectroscopy (XPS).In the previous work we proposed to derive the energy loss function which reproduced the XPS 4f spectrum very well by using the Monte Carlo simulation. This Monte Carlo simulation code describes elastic scattering process by Mott scattering cross-section and inelastic scattering process by differential inelastic mean free path (DIMFP) calculated from energy loss function. Optical loss function and this adjusted loss function obtained for Au are represented by dashed and solid lines in Fig.l, respectively. The intensity of the adjusted loss function is largely enhanced in the low-energy region comparing to the optical loss function. This sort of the enhancement in low energy region for noble metals have also been reported recently by Yubero et al.
Applications of SIMS to electronic materials and devices
Authors: Corcoran S.F. 
Published: June 2020

Over the past decade secondary ion mass spectrometry (SIMS) has played an increasingly important role in the characterization of electronic materials and devices. The ability of SIMS to provide part per million detection sensitivity for most elements while maintaining excellent depth resolution has made this technique indispensable in the semiconductor industry. Today SIMS is used extensively in the characterization of dopant profiles, thin film analysis, and trace analysis in bulk materials. The SIMS technique also lends itself to 2-D and 3-D imaging via either the use of stigmatic ion optics or small diameter primary beams.By far the most common application of SIMS is the determination of the depth distribution of dopants (B, As, P) intentionally introduced into semiconductor materials via ion implantation or epitaxial growth. Such measurements are critical since the dopant concentration and depth distribution can seriously affect the performance of a semiconductor device. In a typical depth profile analysis, keV ion sputtering is used to remove successive layers the sample.
Use of oriented polycrystalline films in x-ray optics
Authors: Wittry D. B. , Chang W. Z. , Barbee T. W. 
Published: June 2020

X-ray diffractors having doubly curved crystal planes can have a high collection efficiency for radiation from a point source and can provide point-to-point focusing of monochromatic x rays as shown by some of the authors. These kinds of diffractors can be used to form x-ray microprobes that can give lower detection limits than electron microprobes or to make wavelength dispersive spectrometers with better signal and signal/background ratio than conventional ones employing the Johann or Johansson geometry. However, fabrication of diffractors of the desired geometry by the use of bent crystals has been difficult. In this paper, we explore the use of oriented polycrystalline films to fabricate doubly curved diffractors for x rays of short wavelength.Oriented polycrystalline films (OPF) have been of interest for many applications, e.g., magnetic recording media, non-linear optical device components, inexpensive large-area substrates for semiconductor device fabrication, etc. These films consist of small monocrystalline grains that have a high degree of preferential orientation of one crystallographic axis relative to the substrate surface.
X-ray diffraction properties of curved crystal diffractors
Authors: Chang W. Z. , Wittry D. B. 
Published: June 2020

Since Du Mond and Kirkpatrick first discussed the principle of a bent crystal spectrograph in 1930, curved single crystals have been widely utilized as spectrometric monochromators as well as diffractors for focusing x rays diverging from a point. Curved crystal diffraction theory predicts that the diffraction parameters - the rocking curve width w, and the peak reflection coefficient r of curved crystals will certainly deviate from those of their flat form. Due to a lack of curved crystal parameter data in current literature and the need for optimizing the choice of diffraction geometry and crystal materials for various applications, we have continued the investigation of our technique presented at the last conference. In the present abstract, we describe a more rigorous and quantitative procedure for measuring the parameters of curved crystals.The diffraction image of a singly bent crystal under study can be obtained by using the Johann geometry with an x-ray point source.
Quantitative x-ray microfluorescence analysis of small areas and individual particles
Authors: Pella P. A. , Lankosz M. , Holynska B. 
Published: June 2020

During the past few years, rapid progress has been made in the development of collimated x-ray sources which permit energy-dispersive x-ray analysis of small areas with dimensions below 100 μm. An x-ray microfluorescence spectrometer developed at NIST employs a commercial low-power (50 WATTS) x-ray tube providing a small focused x-ray beam (0.25 × 0.25 mm). The x-ray beam size was further reduced with a Mo collimator tipped with a Pt foil having a 70μm hole in the center. The x-ray beam profile was measured by step scanning across Cu wires 50 μm in diameter in both X and Y directions. The cross section of the beam was approximated by a Gaussian function with a FWHM of 43 μm. A schematic diagram of the spectrometer which is capable of operation in vacuum is shown in Figure 1.Other features include a close coupled source-sample-detector for optimum count rate, a motorized x-y stage, and a color video camera for continuous viewing of the sample at normal incidence.
Probing the Chemistry and Spectroscopy of Radiation-Sensitive Polymers by Parallel-Detection EELS
Authors: Rightor E. G. , Young G. P. 
Published: June 2020

Investigation of neat polymers by TEM is often thwarted by their sensitivity to the incident electron beam, which also limits the usefulness of chemical and spectroscopic information available by electron energy loss spectroscopy (EELS) for these materials. However, parallel-detection EELS systems allow reduced radiation damage, due to their far greater efficiency, thereby promoting their use to obtain this information for polymers. This is evident in qualitative identification of beam sensitive components in polymer blends and detailed investigations of near-edge features of homopolymers.Spectra were obtained for a poly(bisphenol-A carbonate) (BPAC) blend containing poly(tetrafluoroethylene) (PTFE) using a parallel-EELS and a serial-EELS (Gatan 666, 607) for comparison. A series of homopolymers was also examined using parallel-EELS on a JEOL 2000FX TEM employing a LaB6 filament at 100 kV. Pure homopolymers were obtained from Scientific Polymer Products. The PTFE sample was commercial grade. Polymers were microtomed on a Reichert-Jung Ultracut E and placed on holey carbon grids.
The Use of Correlation Techniques in EELS
Authors: Ouyang F. , Isaacson M. , Kirkland E.J. 
Published: June 2020

The signal rate which is attainable in analyzing small volumes of material in the electron microscope is essentially proportional to the cross-section of the process and the number of atoms probed. When analyzing nanometer scale volumes, small concentrations of material or processes of low probability, the experimenter is always faced with spectra of low signal-to-noise (i.e., poor statistics). Provided that the signal rate is larger than the background counting rate due to the detection system, the main approach to increasing statistics (if the probe current density has been maximized) is just to effectively count for a longer period of time.There are, however, several problems with implementing long counting times on nanovolumes. One is the stability of the incident beam position which effectively limits the analyzed volume. The other is the energy stability of the incident electron beam. For systems with cold field emission sources which are capable of <0.3eV natural energy spreads, the energy stability of the beam is as stringent for EELS as for imaging if one wishes to take full advantage of the narrow energy distribution of the source.
Investigations of Energy Spectroscopic Intensity Distributions in Large-Angle Convergent-Beam Patterns of MoSe2
Authors: Quandt Eckhard , Weickenmeier Andreas , Kohl Helmut , Niedrig Heinz 
Published: June 2020

1.IntroductionWith special experimental arrangements - e.g. the rocking crystal technique (fig. 1) - energy-filtered electron diffraction methods can be used for element specific determination of the crystalline structure. Because of the missing phase information of the recorded large angle convergent beam-like patterns (LACBPs) the structure determination can only be achieved by comparing calculated with measured intensity distributions. Therefor a suitable theoretical model should consider the experimentally selected energy loss, scattering vector and detector aperture to calculate the rocking curve intensities. LACBPs of MoSe2 show significant anomalous absorption for major bands (fig. 2,3a), so that absorption has to be considered in an appropriate theoretical model. To verify the reliability of this method experiments and calculations have been carried out with known structures, e.g. the hexagonal lattice of MoSe2.2.Experimental realizationThe rocking crystal method combined with energy loss spectroscopy of the transmitted electrons allows the recording of energy filtered LACBPs in serial detection mode and energy spectroscopic LACBPs in parallel detection mode as well.
Background Fitting in the Low-Loss Region of Electron Energy Loss Spectra
Authors: Scott C P , Craven A J , Gilmore C J , Bowen A W 
Published: June 2020

The normal method of background subtraction in quantitative EELS analysis involves fitting an expression of the form I=AE-r to an energy window preceding the edge of interest; E is energy loss, A and r are fitting parameters. The calculated fit is then extrapolated under the edge, allowing the required signal to be extracted. In the case where the characteristic energy loss is small (E < 100eV), the background does not approximate to this simple form. One cause of this is multiple scattering. Even if the effects of multiple scattering are removed by deconvolution, it is not clear that the background from the recovered single scattering distribution follows this simple form, and, in any case, deconvolution can introduce artefacts.The above difficulties are particularly severe in the case of Al-Li alloys, where the Li K edge at ~52eV overlaps the Al L2,3 edge at ~72eV, and sharp plasmon peaks occur at intervals of ~15eV in the low loss region. An alternative background fitting technique, based on the work of Zanchi et al, has been tested on spectra taken from pure Al films, with a view to extending the analysis to Al-Li alloys.
Comparison of Images of Crystalline Specimens by Energy-Filtering TEM at 80 keV and CTEM at 200 keV
Authors: Bakenfelder A. , Reimer L. , Rennekamp R. 
Published: June 2020

One advantage of energy-filtering electron microscopy (EFEM) is to avoid the chromatic aberration of conventional transmission electron microscopy (CTEM) by the mode of electron spectroscopic imaging (ESI) using either zero-loss filtering of unscattered and elastically scattered electrons or a narrow selected energy window at the most probable loss of the electron-energy-loss spectrum (EELS). Chromatic aberration can also be reduced by high-voltage electron microscopy (HVEM). Comparisons of ESI at 80 keV and CTEM at 200 keV have already been reported for biological tissues. In this contribution we compare the imaging of evaporated crystalline films with ESI at 80 keV in a ZEISS EM902 and with CTEM at 200 keV in a Hitachi H800/NA.Zero-loss filtering at 80 keV can be applied for maximum mass-thicknesses of x=ρt≃150 μg/cm2 where the zero-loss transmission falls below 0.001 and an energy window at the most-probable energy loss can be used below ≃300 μg/cm2. Inelastic scattering preserves the Bragg contrast.