bluuebunny/crossref_metadata_2025_split huggingface dataset:
Incoherent Stem Imaging at 1.5 Å Resolution With A 200 Kv FEGTEM
Authors: James EM , Browning ND 
Published: July 2020

Abstract
Here we demonstrate sub- 1.5 Å resolution in compositionally sensitive high-angle annular dark-field (HAADF) (“Z-contrast”) imaging. For the first time this has been achieved on a 200 kV field-emission transmission electron microscope (FEGTEM), the JEOL JEM-2010F. With a Gatan imaging filter, this type of instrument is then capable of both analytical imaging and electron energy-loss spectroscopy at similar spatial resolution as in the 300 kV dedicated STEM.
The Z-contrast imaging technique has a spatial resolution given by the size of the electron probe. When used to image periodic specimens and their defects, the effective incoherent nature of the Z-contrast method leads to higher resolution for given lens Cs, higher sensitivity to atomic number and easier qualitative image interpretation than in HRTEM.In practice, the ability to form a small (atomic resolution) probe depends on the brightness of the electron source, and achieving low enough levels of mechanical and electrical instabilities that otherwise incoherently broaden the probe.
Analysis of Diffraction Contrast as A Function of Energy Loss in Energy Filtering Transmission Electron Microscope (EFTEM) Imaging and Possible Implications on High-Resolution Compositional Mapping
Authors: Moore KT , Howe JM 
Published: July 2020

Abstract
The dependence of diffraction contrast on electron energy loss is an important relationship that needs to be understood because of its potential effect on energy-filtering transmission electron microscope (EFTEM) images. Often when either a two-window jump-ratio image or a three-window elemental map is produced diffraction contrast is not totally eliminated and contributes to the intensity of the final EFTEM image. Background removal procedures often are unable to completely account for intensity changes due to dynamical effects (i.e., elastic scattering) that occur between images acquired at different energy losses, leaving artifacts in the final EFTEM image.
In this study, the relationship between diffraction contrast and electron energy loss was investigated by obtaining EFTEM images of a bend contour in aluminum in 100 eV increments from 0 to 1000 eV (Fig. 1). EFTEM images were acquired a JOEL 2010F FEG TEM with a Gatan imaging filter (GIF) at a microscope magnification of 8 kX using a 1 eV/pixel dispersion, 2X binning (512 x 512) and exposure times ranging from 0.25 s for 0 eV energy loss up to 132 sec for 1000 eV energy loss.
Segregation of Silicon in Metal-Alumina Composites
Authors: Hashimoto RY , Menon ESK , Fox AG 
Published: July 2020

Abstract
A common impurity in polycrystalline commercial alumina is Si since silica is often added as a sintering aid. There have been several studies on impurities in alumina, and substantial degree of grain boundary segregation has been found to occur. Alumina-metal composites have found several applications especially in the electronic industry and consequently systems such as alumina-copper have been studied exhaustively. However, the role of impurities in metal-alumina composites has not been fully explored. Studies of Pt-alumina composites has shown that silicon is present at the interface of vacuum, diffusion bonded samples. Our earlier studies have shown that Si indeed segregates to the triple junctions and grain boundaries in alumina and in alumina-copper composites, often Si segregates to the metal-ceramic interfaces as well. This investigation concentrates on the distribution of silicon in copper-alumina in comparison to aluminum-alumina composites.
The metal-ceramic composites were prepared by diffusion bonding 99.99% pure metal foils sandwiched in between commercially available sintered alumina (∼99.5% pure) substrates for several hours in vacuum.
Electron Beam Induced Damage of GaN And Changes in EELS
Authors: Eustis TJ , Silcox J 
Published: July 2020

Abstract
GaN-based materials hold promise for electronic and optical applications. Lacking a suitable lattice matched substrate, microstructural investigation by electron microscopy has become an important player in the development of these materials. Electron microscopy investigations vary from standard defect analysis, to polarity determination, to evaluation of electronic structure. To date, no evidence of electron beam damage has been reported.
For this experiment, the beam current from the Cornell University VG501 lOOkV STEM was approximately 0.3nA. During acquisition of multiple PEEL spectra of the N K-edge, the intensity of the core loss decreased and eventually disappeared due to electron beam induced damage. Damage is a function of dose. Thus observation of damage is dependent upon magnification and thickness, i.e., electron dose and fractional change in signal.
A Method for Determining the Volume Fraction of Sub-Micron Particulates in Aluminum Alloys Using Energy Filtered Transmission Electron Microscopy (EFTEM)
Authors: Steele D , Ball M , Lloyd DJ 
Published: July 2020

Abstract
The microstructure and mechanical properties of alloy systems are known to be influenced by the size and distribution of sub-micron dispersoids through boundary pinning and Orowan strengthening. Explaining and accurately predicting the behaviour of these systems relies in part on the measurement of the volume fraction of the second phase precipitates. The transmission electron microscope (TEM) provides the necessary resolving power to measure the dispersoids of interest, and when coupled to Electron Energy Loss Spectroscopy (EELS) based filtering systems, the thickness of the observed volumes can be determined using the log-ratio technique.
A series of nominally AA5754 alloys with increasing Manganese content (0%, 0.2%, 0.5%, 0.8%) was used to evaluate the method. The data was collected using a Philips FEGSTEM equipped with a Gatan Imaging Filter (GIF). A series of images were collected from each of a number of contiguous fields in each specimen. These included an unfiltered image, an image collected from the zero-loss region of the transmitted spectrum, and a filtered image generating sufficient precipitate contrast to allow subsequent spatial measurement. Using a filtered image, the contribution of diffuse scattered electrons is minimized, thus enabling the analysis of thicker regions.
The Use of ELNES for Microanalysis
Authors: Craven AJ , MacKenzie M 
Published: July 2020

Abstract
The performance of many materials systems depends on our ability to control the distribution of atoms on a nanometre or sub-nanometre scale within those systems. This is as true for steels as it is for semiconductors. A key requirement for improving their performance is the ability to determine the distribution of the elements resulting from processing the material under a given set of conditions. Analytical electron microscopy (AEM) provides a range of powerful techniques with which to investigate this distribution. By combining information from different techniques, many of the ambiguities of interpretation of the data from an individual technique can be eliminated. The electron energy loss near edge structure (ELNES) present on an ionisation edge in the electron energy loss spectrum reflects the local structural and chemical environments in which the particular atomic species occurs. Thus it is a useful contribution to the information available. Since a similar local environment frequently results in a similar shape, ELNES is useful as a “fingerprint”.
Some Things Never Change - The Microcrystallite Story After 25 Years
Authors: Gibson JM , Treacy MMJ , Voyles PM 
Published: July 2020

Abstract
When I (JMG) began my Ph.D. studies under the supervision of Archie Howie in 1975, he was still licking his wounds over one of the very few apparently incorrect publications[l] of his career. I am proud that our recent work has shown that, far from being wrong, Archie and Lee Rudee were actually 25 years before their time. It was in the early 1970’s that electron microscopy instrumentation reached the performance level that was adequate to resolve the interplanar spacings in elemental materials, such as the semiconductors silicon and germanium. It immediately became of interest to examine the structure of amorphous silicon and germanium, in the expectation that direct imaging could resolve the old controversy between micro-crystallite and random network structural models. Porai-Koschits was the first to suggest that amorphous materials comprised extremely small crystalline domains (microcrystals), in contrast Zachariasen[2] proposed that a continuous random network was a better description of glassy materials.
Quantitative Valence-Loss Spectroscopy of Carbon Nanostructures
Authors: Stöeckli T , Wang ZL , Bonard J-M , Stadelmann P , Châtelain A 
Published: July 2020

Abstract
Carbon tubes or spheres synthesized by arc-discharge are usually mixed with other byproducts, prohibiting direct measurements of their physical properties by the well established optical techniques because a large quantity of pure specimen is required. Electron energy-loss spectroscopy (EELS) is a unique technique that can be applied to probe the electronic structure of a single carbon tube or sphere. In this paper, the classical dielectric response theory is applied to calculate the EELS spectra acquired from a graphitic carbon sphere at various impact parameters. Graphite is an anisotropic dielectric medium whose dielectric function is described by a tensor. A graphitic carbon sphere is composed of concentric graphitic shells whose dielectric tensor in the spherical geometry, under the local response approximation, is given by (Figure 1)

where are the dielectric function of graphite for an electric field perpendicular and parallel, respectively, to the c axis. In the non-relativistic approximation, the surface excitation is calculated by [1]
Structure and Composition of Supported Pt-Sn Electrocatalysts
Authors: Radmilovic V , Richardson T , Chen SJ , Ross PN 
Published: July 2020

Abstract
Bimetallic alloy particles supported on high-surface area carbon are widely used as electrode materials. Because of their stability, Pt-Sn alloys are of particulate interest for a variety of applications. Although the reasons for the superior properties of these catalysts are not fully understood, the dispersion, structure, and compositional homogeneity of the alloy clusters, are clearly important factors in determining their catalytic activity. In order to identify the composition and structure of Pt-Sn base nanoparticles, various characterization techniques, mainly X-ray diffraction (XRD) and transmission electron microscopy (TEM) [1], have been applied. However, very often conflicting conclusions regarding to the structure of Pt-Sn particles have been reported. The focus of the present work is to examine a commercially available carbon supported bimetallic Pt-Sn catalyst, with a nominal Pt:Sn wt. ratio of 2:1 (500N and 900N samples) and 3:1 (E270 sample), using high resolution electron microscopy (HREM), electron and X-ray diffraction techniques, and microchemical analysis by energy dispersive X-ray spectroscopy (EDS).
Characterization of Ceramics Using Electron Backscatter Diffraction in the SEM
Authors: Michael JR 
Published: July 2020

Abstract
The technique of electron backscatter diffraction (EBSD) in the scanning electron microscope is becoming a standard technique for the characterization of materials. EBSD has evolved into a tool that can determine the orientation of a crystalline area of interest or the technique can be used for the identification of unknown phases from their composition and crystallography. The application of the technique to ceramic materials has demonstrated the many advantages of this technique over classical x-ray diffraction techniques or electron diffraction in the TEM.
EBSD patterns are obtained by illuminating a highly tilted sample (&gt;45° from horizontal) with a stationary electron beam. Electrons that are backscattered from the sample may satisfy the condition for channeling (or diffraction) and produce images that contain bands of increased and decreased intensity that are equivalent to channeling patterns. The patterns are imaged by placing a phosphor screen near the sample and imaging the screen with either TV rate or a slow scan CCD camera.
Electron Microscopy of Hierarchical Materials
Authors: Blanford CF , Stein A , Carter CB 
Published: July 2020

Abstract
Recent innovations in materials chemistry have allowed the preparation of “hierarchical” ceramic and polymer materials that possess features on several different size scales. One of the newest hierarchical materials are ceramics that exhibit a three-dimensional ordered array of half-micron voids. These macroporous structures are synthesized from a liquid ceramic precursor and a polymer colloidal crystal template. This template is extracted by either thermal or chemical methods leaving a structure such as the porous zirconia particle shown in Fig. 1. The final structure of these materials may be thought of as the opposite of opal: the spheres here are the voids. Ordered arrays of dielectric material like these could potentially be used as photonic crystals that interact with visible light. For the microscopist, these materials create new opportunities to study interrelated aspects such as templating, crystallization, and phase transformations.
Transmission electron microscopy (TEM) was carried out on a Philips CM30 TEM equipped with a LaB6 filament and operating at 300 kV.
Effect of Correction of the 3-Fold Astigmatism on HREM Lattice Imaging With Information Below 100 Pm
Authors: Wang YC , Fitzgerald A , Nelson EC , Song C , O’Keefe MA , Kisielowski C 
Published: July 2020

Abstract
High resolution electron microscopes with field emission sources opened the possibility to investigate solids on a 100 pm range. Either electron holograpy can be applied or an information limit that may even extend into a region below 100 pm can be exploited to reach this goal [1]. However, lens aberrations such as the three-fold astigmatism often complicate an image interpretation in the 100 pm range or even make it impossible [2]. On the other hand, there is growing need to understand physical processes at a mono-atomic level in order to further develop artificially structured materials such as nano-crystals, ceramic coatings or semiconductors. Commonly, such materials contain light elements like C, N, or O with bond lengths that are shorter than a typical 180 pm point resolution of a high resolution, electron microscope. The carbon-carbon distance of 150 pm is the shortest bond length value in crystalline solids. Moreover, any projection of a diamond lattice along a low index zone axis for lattice imaging leads to a reduced C-C distance.
Use of Electron Diffraction for Determining the Orientation of Rapid Thermally Annealed Lead Zirconate Titanate Thin Film On (111) Pt Coated Si Substrate
Authors: Cheng SC , Su T , Trolier-McKinstry S 
Published: July 2020

Abstract
Lead zirconate titanate (PZT) is a perovskite-staictured material which is ferroelectric over most of the solid solution and which exhibits a range of electrical and electromechanical properties depending on the Zr/Ti ratio. Thin film PZT is currently being developed for piezoelectric actuators, ferroelectric memory devices and pyroelectric detectors. The ferroelectric properties and microstructures of the PZT films depend upon numerous processing parameters.In this research, sol-gel PZT films crystallized by rapid thermal annealing at 700°C for 30 seconds were investigated. A modification of the procedure described by Budd, Dey and Payne was utilized for the solution preparation. The electrodes/substrates which have been used for the deposition of PZT are Pt/Ti/SiO,/Si. The approximate thicknesses of Pt, Ti and SiO2 layers are 150 nm, 20 nm and 1000 nm, respectively. Transmission electron microscopy (TEM) was used to reveal the microstructure of the films, including the interfacial characteristics, grain sizes and domain structures. Cross sectional specimens were prepared by the following procedures.
Microstructure of Yba2Cu3O7 Thick Films by Post Annealing of the Precursor by High Rate E-Beam Deposition On SrTiO3 Substrates
Authors: Wu Lijun , Zhu Yimei , Suenaga M , Sabatini RL 
Published: July 2020

Abstract
Recently, considerable efforts have been made in developing a fabrication procedure for YBa2 Cu3O7-δ superconducting films on a metallic substrate tape for electrical power applications. The central issue is to develop a method, which can produce the tape in sufficiently long lengths at a commercially viable cost. One possible approach is the so-called BaF2 post-deposition annealing process, which involves deposition of an unreacted mixture of a BaF2 -Y-Cu-O layer on a substrate by electron beam evaporation method, followed by heat-treatment of the layer in a mixed-gas atmosphere of a low partial pressure O2, saturated H2 O, and N2. To fabricate thick and long films, it is important to understand the effects of the heat-treatment parameters on the. structure and the properties. Here, we report our structural analysis of the films annealed at different temperatures.
The films annealed at 725°C, 750°C and 800°C have a similar phase assemblage which are composed ofYBa2 Cu3O7-δ and Y2O3, CuO and Ba-Ti-Sr-O precipitates, as shown in fig. la.
TEM Microstuctural Characterization of a 2091 (Al-Li-Mg-Zr) Alloy Subjected to Welding Operations
Authors: de Macedo MCS , Solórzano IG 
Published: July 2020

Abstract
For over two decades considerable effort has been directed towards the development of Al-Li base alloys with the objective of replacing conventional high aluminum alloys, due to the fact that lithium additions cause substantial reduction in density accompanied by significant increase in the elastic modulus, implying, therefore, in appreciable improvement in the specific properties of the resulting alloys. These properties depend on the miscrostucture evolution during heat treatment or welding cycle. The microstructure of the commercial Al-Li systems is complex due to the addition of alloying elements, which increases the number of the allowed stable and metastable phases. During the thermo-mechanical processing of the 2091 alloy, the probable metastable are δ’, GPB zones and S’, the stable phases are S, T2 and the high temperature R (1-3). Further, the Zr precipitates the Al3Zr. The present study deals with the microstructure evolution of welded joints of the 2091 alloy studied by transmission electron microscopy, TEM.
Formation of Γ Phase on Hot-Dip Galvanized Coating Steel Sheet after Various Heat Treatment
Authors: Lin Yuli , Lin Hwang-Che 
Published: July 2020

Abstract
Among those intermetallic phases in Zn-Fe system formed in the hot-dip galvanized coating and/or galvanneal coating, the microstructure of Γ phase was the least mentioned. The Γ phase form in the coating layer is usually too thin to observe by a microscope. However, it has been reported that the performance of coating is closely related to the microstructure of Γ phase. Tokunaga et al. has reported that the cracks were generated from the Γ layer or Γ+δ layer. Y.Lin et al. demonstrates that coherent interface forms between Γ and steel interface on annealed electrogalvanized steel sheets indicating that failure would not occur at this interface.
Samples used in this study were lab-made hot-dip galvanized steel sheets. To investigate the microstructure of coating, especially the Γ phase layer, specimens were heated to create the designed layer interface. It was found that the heat-treated conditions ranged from 700°C to 750°C for one hour was appropriate to observe the nucleation and growth of Γ phase layer.
Imaging Dislocations in Duplex Tial Using Electron Channeling Contrast
Authors: Ng BC , Bieler TR , Crimp MA 
Published: July 2020

Abstract
Electron channeling contrast imaging (ECCI), performed using a scanning electron microscope, has been used to observe dislocations in bulk TiAl with a duplex microstructure. The ECCI technique is based on the dependence of the back-scattered electron (BSE) yield (of the incident beam orientation) on the crystal lattice and defect orientation near the specimen surface. This allows nearsurface defects to be imaged in bulk specimens [1, 2]. ECCI was carried out in a Camscan 44FE FEG-SEM operated at 25 kV using a beam divergence of ∽8 mrad and a beam current of ∽ 2nA. Specimens were observed at a working distance of approximately 11 mm. To record the BSE signal, the microscope was fitted with an annular (four quadrant) silicon diode detector array attached to the final lens pole-piece, resulting in a solid angle collection of approximately ∽0.6 π str. Images were recorded as 32 frame averages using ∽1.1 frames/sec.
Cross-Sectional Transmission Electron Microscopy Sample Preparation Using Focus Ion Beam Machine and Wedge Technique
Authors: Li Du , Zhou Rose , Zanoya Rob 
Published: July 2020

Abstract
As features on an IC chip become smaller than the resolution power of an optical microscope and of the size of the grinding particles, the trend for preparing cross-sectional transmission electron microscopy (TEM) samples at specific locations (bits) is moving towards using a focused ion beam (FIB) machine. Details on how to use a FIB machine to prepare cross-sectional TEM samples have been outlined in many references.The general procedure is to first mark the specific location (bit) in the FIB machine and then grind the sample down to about 20 microns, 10 microns on each side of the feature of interest. After grinding, the sample is mounted on a pre-cut TEM grid and thinned with the FIB to about 0.1 micron in the region containing the feature of interest. There are several disadvantages to this method. First, the sample goes into the FIB machine at least twice—once for FIB marks on the location and once again for the final thinning.
Defect Analysis and Process Development of Microelectronics Devices Using Focused Ion Beam and Energy Filtering Transmission Electron Microscopy.
Authors: Pantel R , Mascarin G , Auvert G 
Published: July 2020

Abstract
1. Introduction.
With continuing reductions in semiconductor device dimensions high spatial resolution physical and chemical analysis techniques will be more and more required for defect analysis and process development in the microelectronics field. Transmission Electron Microscopy (TEM) analysis is now extensively used thanks to the fast Focused Ion Beam (FIB) specimen preparation technique which has furthered its development. Recently, we have shown the advantages of adding Electron Energy Loss Spectroscopy (EELS) to FIB-TEM analysis for semiconductor process characterization. In this paper we extend the EELS technique using FIB sample preparation to Energy Filtering TEM (EFTEM) observations. The EFTEM analysis allows high-resolution compositional mapping using spectroscopic imaging of core level ionization edges3. We show some applications of FIB-EFTEM to defect analysis and process development.
2. Experimental details.
The FIB system is a MICRION model 9500 EX using a gallium ion beam of 50 keV maximum energy with a 5 nm minimum spot diameter.