bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Study Of Diffusion Zones With Electron Microprobe Compositional Mapping
Authors: Marinenko R. B. , Bright D. S. , Handwerker C. A. , Mecholsky J. J. 
Published: June 2020

Digital compositional mapping with the electron microprobe has been used to study diffusion zones at metal-metal and metal-glass interfaces. Image enhancement techniques and concentration-histogram images (CHI’s) have been used with these digital maps to improve visual display and interpretation of the movement of elements in these zones.Metal-Metal Interface. In figure la is a WDS concentration map of gold taken from a specimen of a gold sheet about 40 μm wide sandwiched between two platinum sheets. This specimen was observed as part of a metallurgical study of some ancient Ecuadorian artifacts to better understand the original reaction/diffusion zone between these two metals. The specimen was annealed at 1350°C for 3 min. and then rapidly cooled. This temperature was sufficient to melt the gold (M.P. 1064°C) but not the platinum (M.P. 1769°C). The map in figure la shows that some platinum has diffused into the gold region, but the extent of diffusion is difficult to see in this original grey-level image.
Characterization of occurence and distribution of invisible gold in ore by EPMA
Authors: Mao Shuihe 
Published: June 2020

Owing to the invisibility of ultramicron gold (invisible gold) in “Carlin type” gold ore, it is extremely difficult to investigate its occurrence and distribution by conventional determinative means.EPMA has been proved to be very powerful instrument for doing research on this subject because it has advantages of high space resolution, nondestructive,getting quantitative analysis results and observing various kinds of images continuously with same equipment etc.The unoxidized ore sample is selected from drill cuttings at a “Carl in type” gold mine in Southwest China with gold tenor of 31.02 g/t and weighs 2438g. The operating conditions of EPMA are: accelerating voltage 25kV, beam current 1×10-8 A, beam diameter about 1 μm. AuLα but not AuMα is preferably chosen as analysed x-ray line, because AuMα1 (5.840A) is overlapping with the 3rd order line of FeKα (5.812A) to some extent and iron is the main component of pyrite matrix. According to the expression of detection limit(CDL ), the calculated value of CDL under the circumstances is 0.038%.
Individual Coal Flyash Particles Analysis by EPMA
Authors: Sándor S. , Török Sz. , Xhoffer C. , Van Grieken R. 
Published: June 2020

Flyash is an extremly heterogeneous particulate material. The morphology and composition of the particles depend on the burning technology and the coal type. Fractionated bulk analysis and individual particle analysis have to be applied to obtain relevant data on the particle formation procedure.Flyash was sampled in Hungary from 230 MW power station burning third class brown coal mixed with slag. Burning temperature was 1100-1200 C°. A JSM-840 SEM equipped with ORTEC energy dispersive spectrometer was used for morphological studies. Emitted x ray spectra of the particle were measured by adjusting beam settings manually. For automatic particle analysis a JSM-733 superprobe was used with TRACOR particle recognition and characterization (PRC) system. Accelerating voltage was set to 25 and 35 kV and current to 0,3-1.0 nA. In order to detect heavier element traces like As, Rb, Sr and Pb a 100 μm Mo foil was placed into the electron beam. As a result the irradiated area was 2mm in diameter.
Correlative Light, Scanning and Transmission Electron Microscopy of Rat Lungs After Short-Term Exposure to Cadmium Compounds
Authors: Paulini I. , Thiedemann K.-U. , Dasenbrock C. 
Published: June 2020

Chronic environmental or workplace inhalation exposure to Cadmium (Cd) compounds may cause lung cancer. The morphological changes induced by short term Cd inhalation exposure have not been investigated. Nevertheless, they might give some insight into the sequence of morphological alterations and the events leading to the development of preneoplastic lesions. In this study, the acute morphological changes in rat lungs due to short term Cd exposure were investigated by correlative light (LM), scanning (SEM) and transmission electron microscopy (TEM).Rats were exposed to Cd oxide (CdO), Cd chloride (CdCl2), and Cd sulfide (CdS) (270 μg Cd/m3; 18 hrs/d) for 3 d, 9 d, 4 wks, and 4 wks plus 16 wks clean air (recovery groups). Animals were sacrificed 2 d after the end of the exposure period. Lungs were fixed by intratracheal instillation of a 2% glutardialdehyde in Na-cacodylate buffer solution (pH 7.3; 190 mOsmol; 4°C) under a pressure of 20 cm water column and postfixed in 1% Osmium tetroxide (same buffer).
Beam Size in A High-Resolution Ion Microprobe Operated at High Current
Authors: Orloff J. , Swanson L.W. , Li Jia-Zheng , Tuggle Dave 
Published: June 2020

In recent years the development of liquid metal ion (LMI) sources has made it possible to produce high intensity focused ion beams - beams with current densities of the order of a few amperes per square centimeter and diameters of from less than 50 nanometers to a few micrometers [1,2]. These beams have been applied in areas such as scanning ion microscopy, surface analysis, lithography, implantation and micromachining (removing minute amounts of material in a precise and programmed way). In terms of technological utility micromachining has been the most important of these applications and dozens of focused ion beam systems are in use around the world, for failure analysis and circuit modification. These latter applications depend on the ion beam for removing minute amounts of material from a surface, inspecting the modified surface and for decomposing metal-bearing gases so as to deposit conducting runs on circuits.Some of the features of LMI sources that make them so useful for focused beams are: a high angular intensity of 20 microamperes/steradian, typically [3]; a small apparent source size δ of roughly 50 nanometers [4,5]; wide variety of ionic species including Ga, In, Be, Au, Si, As and B (the latter five species requiring a mass-filtering focusing column); great compactness and extremely reliable operation.
Transmission Electron Microscopy of Evaporated Perylene Thin Films
Authors: Ewins C. , Fryer J.R. 
Published: June 2020

The preparation of thin films of organic molecules is currently receiving much attention because of the need to produce good quality thin films for molecular electronics. We have produced thin films of the polycyclic aromatic, perylene C10H12 by evaporation under high vacuum onto a potassium chloride (KCl) substrate. The role of substrate temperature in determining the morphology and crystallography of the films was then investigated by transmission electron microscopy (TEM).The substrate studied was the (001) face of a freshly cleaved crystal of KCl. The temperature of the KCl was controlled by an electric heater or a cold finger. The KCl was heated to 200°C under a vacuum of 10-6 torr and allowed to cool to the desired temperature. The perylene was then evaporated over a period of one minute from a molybdenum boat at a distance of 10cm from the KCl. The perylene thin film was then backed with an amorphous layer of carbon and floated onto copper microscope grids.
Three-Dimensional Display of Secondary Ion Images
Authors: Lee J.-J. , Hunter J.L. , Lin W.-J. , Linton R.W. 
Published: June 2020

Since the sample surface region is continuously sputtered in dynamic secondary ion mass spectrometry (SIMS), three dimensional (3D) chemical maps can be obtained by acquiring a series of two dimensional (2D) images. Owing to the limitations of the ion beam sputtering technique, SIMS analysis artifacts resulting from factors such as surface roughness, matrix effects, and atomic mixing are present in the 3D volume data. One potential advantage of using 3D display is to provide visual feedback regarding the elimination of artifacts by utilizing correction algorithms as well as correlative information obtained from other surface imaging techniques. In this paper, SIMS 3D maps are displayed by a volume rendering technique in which more information is retained in the image processing steps.Various 3D display methods have been proposed for SIMS and other microscopic imaging techniques. Some of the previous methods can not display the complete 3D spatial distribution of mass-selected ion intensities.
Electron spectroscopy in SEM and STEM
Authors: Venables J. A. , Hembree G. G. , Harland C.J. 
Published: June 2020

Low energy electrons, in the energy range 0-2 keV, are very useful in surface science. Both secondary (0-100 eV nominally) and Auger (50-2 keV) electrons can be used as analytic signals in ultra-high vacuum (UHV) scanning (SEM) and scanning transmission (STEM) electron microscopes. This paper briefly reviews some ongoing projects, which are aimed at improving the spatial resolution and information content of these signals.Both secondary electron imaging (SEI) and Auger electrons spectroscopy (AES) have a long history. Reviews of AES and its microscopic counterpart scanning Auger microscopy (SAM) have been given previously in this International Conference Series; over the intervening period AES/SAM instruments have become widely available commercially. Simply biassing the sample up to a few hundred volts (-ve) has lead to a new technique (biassed-SEI) which is sensitive at the sub-monolayer level. In general biassing the sample is a useful additional experimental variable. It can be used to visualize thin films and surface topography, including steps; it can also be used to distinguish spectral features (eg Auger peaks) from the sample from those due to stray electrons, and to place such features in the best energy region for the electron spectrometer.
A Study of DIGM in Ag/Cu system by AEM
Authors: Liu G. X. , Guan Z. M. , Williams D. B. , Notis M. R. 
Published: June 2020

DIGM phenomenon is very similar to the diffusion process and the coupled migration of the reaction front occured in discontinuous precipitation. It is likely to postulate that DIGM may occur in the system where discontinuous precipitation appears. W. Kim and co-author have Investigated DIGM In six copper alloy systems (Ag/Cu, Mg/Cu, Sb/Cu, In/Cu, Cd/Cu and Sn/Cu) in which discontinuous precipitation has been found. In Kim s experiment, the diffusion treatments were conducted at 400 °C and 450 °C for 4 days, Kim found DIGM occurred in 4 systems, i. e. Sb/Cu, In/Cu, Cd/Cu and Sn/Cu, but in Ag/Cu and Mg/Cu systems no DIGM was found.In order to test whether there is DIGM or not in Ag/Cu system, we reexamlned the DIGM phenomenon in Ag/Cu under 400 °C and 480 °C for 5 days diffusion, finally DIGM was found in this system. In different segments of a same boundary the bulging directions and the migration distances may be different as indicated in Fig. 1.
AEM of Ti50Ni40Cu10 Shape Memory Alloys
Authors: Pelton A. R. , Adler P. H. , Yu W. , Holt R. , McConville R. 
Published: June 2020

Equiatomic Ni-Ti alloys exhibit shape-memory properties, whereby an article deformed at low temperature regains its original shape at higher temperatures. This effect is due to a reversible martensitic transformation; in binary alloys the parent phase has an ordered cubic (B2) structure which transforms to a monoclinic B19' structure. Substitution of approximately 10% Cu for Ni results in an improvement of shape memory properties which has been attributed to a two-step martensitic transformation from B2 to untwinned B19 and then to twinned B19'. There is, however, some controversy in the literature concerning which phases are in equilibrium and which type of martensite is stable after various thermomechanical treatments. The purpose of this paper is to report on the preliminary findings from an AEM study in order to illuminate the microstructural origins of these controversies.Ti50Ni40Cu10 alloys were cast in a plasma-arc furnace, sectioned and prepared for scanning and transmission electron microscopy.
Determination of Static Displacements of Atoms by Means of Large-Angle CBED
Authors: Tomokiyo Yoshitsugu , Kuroiwa Takeharu 
Published: June 2020

The extinction distance ξ g for electrons becomes large with the increase in an index of excited reflection g. The quasi-kinematical treatment would be applicable if the crystal thickness t is smaller than ξ g/π . When large-angle convergent electron beam is illuminated on a small area of crstal, many reflections may simultaneously satisfy the Bragg conditions and the thickness of the area is considered to be uniform. We can record the intensities of the many reflections on a negative film. If the crystal is tilted so that the high index reflections may fulfill the Bragg conditions, their intensities are sensitive to atom positions in the crystal. In the present paper we will show our recent study on the determination of the static displacement of Al atom in α Al2O3. Our interest is placed on the applicability and accuracy of the quqsi-kinematical treatment.In αAl2O3 (corundum structure) oxygen atoms ideally form a hexagonal close packed layer and aluminum atoms occupy 2/3 of centers of octahedra formed by oxygen atoms.
Scattering of Quasi-Bloch Wave Sets by a Crystal With Defects
Authors: Borgardt N. I. 
Published: June 2020

Application of electron microscopy methods (high resolution electron microscopy (HREM), convergent-beam electron diffraction (CBED)) permitting quantitative information of a defect structure to be obtained causes the necessity of developing a theory of scattering fast electrons by the real crystal.Determination of the electron wave function by the multislice or real space methods which provide a high accuracy requires numerical calculations for a crystal of a large volume and is restricted to foils with thicknesses of several tens of nanometrs. Effective application of approaches based on the solution of differential equations for amplitudes of diffracted waves or Bloch waves and being widely used for qualitative description of images with a diffraction contrast, is possible only in combination with a column approximation. This approximation, however, is not sufficient for a quantitative analysis, nor is it enough for interpretation of images and diffraction patterns obtained under CBED conditions.In the present paper, formalism of the Bloch waves is generalized by introdusing the idea of quasi-Bloch wave sets.
Micromorphological Studies on Flux Grown RFeO3 (R = Dy, Ho) Crystals Using SEM and EDAX Techniques
Authors: Kotru P. N. , Kachroon S. K. , Razdan A. K. , Wanklyn B. M. 
Published: June 2020

Results are presented of microtopographical studies on rare-earth orthoferrite RFeO3 (R = Dy, Ho) crystals by scanning electron microscopic and energy-dispersive x-ray analytical (EDAX) techniques. The flux growth yields crystals with habit faces. These crystals are therefore suitable for surface structural studies.The crystals of RFe03 (R = Dy, Ho) are grown from starting compositions of R203, Fe203 (solute), Pb0, PbF2 (solvent), and B203 (additive) in a platinum crucible; the growth procedure has been reported previously. Figures 1 and 2 illustrate platinum deposits on an HoFe03 surface. The modification of advancing growth fronts by an imperfection on an HoFe03 surface is illustrated in Fig. 3.X-ray mapping and elemental line profiles taken across some peculiar structures on an RFe03 crystal indicate that the areas covered by the structures are rich in R but deficient in Fe. Almost the same observations were made on DyFe03 crystals. It is concluded that use of PbO-PbFe2-B203 flux systems for the growth of RFe03 (R = Dy, Ho) results in the precipitation of magnetoplumbite (PbFe12019) and R0F.
The Analyses of Anthropogenic Atmospheric Particulates by EM
Authors: Russell Philip A. 
Published: June 2020

This presentation will summarize fourteen years of research on the physical and chemical nature of particulates suspended in the earths atmosphere utilizing scanning electron microscopy and, to a lesser extent, transmission electron microscopy. Topics to be discussed include (1) the rationale for using electron microscopy to study airborne particulates, (2) methods for collecting airborne particulates, (3) methods of analysis and (4) a summary of results. Examples will demonstrate how conclusions about the nature and source of collected particles can differ between bulk sample analyses and discrete particle analyses. Without the input from discrete particle analyses, bulk analytical techniques may produce serious errors in the apportionment of airborne particulates to specific sources.The scanning electron microscope (SEM) and transmission electron microscopy (TEM) have proven themselves to be the preferred instruments to use in the study of discrete fine particles because they permit sufficient resolution and analytical capabilities to examine the structure and chemistry of individual particles less than a few micrometers in diameter.
Lens-field axis alignment: a new objective lens alignment for high-resolution Electron Microscopy
Authors: Ishizuka K. , Shirota K. 
Published: June 2020

Accurate alignment of an electron microscope is important when the highest achievable resolution is demanded. In a conventional alignment for high-resolution electron microscopy, the incident beam direction is aligned for the object point imaged at a viewing-screen center. It should be noted however that the object point corresponding to the viewing-screen center does not usually located on the magnetic-field axis of an objective lens due to lens misorientation and/or beam deflection caused by a leakage field around the objective lens. Then, the voltage-center and coma-free conditions cannot be satisfied simultaneously, even if a magnetic-field is rotationally symmetric. We implemented last year a proposed scheme to satisfy both coma-free and voltage-center conditions. This alignment scheme however requires a suitable deflector at the objective image plane.In this report, we summarize ordinary alignment procedures for high resolution electron microscopy and propose a new alignment procedure, which we call a lens-field axis alignment. Using this alignment we can satisfy the coma-free and voltage-center conditions simultaneously.
Computer control of Transmission Electron Microscopes possibilities, concepts and present limitations
Authors: Völkl E. , Allard L.F. , Dodson T.A. , Nolan T.A. 
Published: June 2020

The electron microscope laboratory at the High Temperature Materials Laboratory in Oak Ridge National Laboratory runs essentially film free. This is possible due to the use of TV-rate and slow-scan CCD cameras together with fast desktop computers connected through Ethernet to network servers for image storage and a variety of hard copy output devices. In our experience, the functionality of a film-free laboratory goes beyond the simple replacement of film material with some other storage media. For example, the tim and effort to produce a final hardcopy image has been reduced effectively from several hours to several minutes. At the same time, data accuracy has increased due to the high linearity of the CCD cameras and data safety is improved due to automated nightly backups.The present all-digital setup of our TEMs has already changed the routines on how an TEM is run. Two si uations occur regularly: 1) one microscopist moves back and forth between the TEM and the computer and 2) two microscopists run the computer and/or TEM as a team. Unfortunately, the tasks of recording an image and running the microscope are still very much separated.
High-resolution measurement of birefringent fine structure in living cells using a new polarized light microscope
Authors: Oldenbourg Rudolf 
Published: June 2020

The recent renaissance of the light microsope is fueled in part by technological advances in components on the periphery of the microscope, such as the laser as illumination source, electronic image recording (video), computer assisted image analysis and the biochemistry of fluorescent dyes for labeling specimens. After great progress in these peripheral parts, it seems timely to examine the optics itself and ask how progress in the periphery facilitates the use of new optical components and of new optical designs inside the microscope. Some results of this fruitful reflection are presented in this symposium.We have considered the polarized light microscope, and developed a design that replaces the traditional compensator, typically a birefringent crystal plate, with a precision universal compensator made of two liquid crystal variable retarders. A video camera and digital image processing system provide fast measurements of specimen anisotropy (retardance magnitude and azimuth) at ALL POINTS of the image forming the field of view. The images document fine structural and molecular organization within a thin optical section of the specimen.
Visualization of β-sheets and some amino acid side chains in 400 kV electron images of streptavidin crystallized on phospholipid monolayers
Authors: Avila-Sakar Agustín J. , Chiu Wah 
Published: June 2020

Two-dimensional (2-D) protein crystallization on lipid monolayers is an emerging technique with potential application to structure elucidation of biological macromolecules (Uzgiris and Kornberg, 1983). Among more than a dozen proteins or macromolecular assemblies which have been crystallized by this technique, streptavidin 2-D crystals diffract electrons beyond 3 Å (Kubalek, et al., 1991), indicating that structural information from them is retrievable to near-atomic resolution. This 15 kD protein, synthesized by Streptomyces avidinii, is probably the single most widely used protein in modern biochemical assays. It forms nearly irreversible complexes (Kd ≈ 10-15 M) with the vitamin biotin and biotinylated molecules, which can be detected by a variety of methods.2-D streptavidin crystals were grown on biotinylated lipid monolayers by a method similar to that of Kubalek, et al., 1991. They were preserved in vitreous ice for electron cryomicroscopy. Electron images were recorded at 400 kV under flood beam illumination at a dose of 8 e-/Å2. Phases from four micrographs were merged.
High-voltage Electron Microscopy: Where it is and where it may be going
Authors: Allen Charles W. 
Published: June 2020

High voltage TEMs were introduced commercially thirty years ago, with the installations of 500 kV Hitachi instruments at the Universities of Nogoya and Tokyo. Since that time a total of 51 commercial instruments, having maximum accelerating potentials of 0.5-3.5 MV, have been delivered. Prices have gone from about a dollar per volt for the early instruments to roughly twenty dollars per volt today, which is not so unreasonable considerinp inflation and vastly improved electronics and other improvements. The most expensive HVEM (the 3.5 MV instrument at Osaka University) cost about 5 percent of the construction cost of the USA's latest synchrotron.Table 1 briefly traces the development of HVEM in this country for the materials sciences. There are now only three available instruments at two sites: the 1.2 MeV HVEM at Argonne National Lab, and 1.0 and 1.5 MeV instruments at Lawrence Berkeley National Lab. Fortunately, both sites are user facilities funded by DOE for the materials research community.