bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of IN-SITU Converted Chrysotile Asbestos Fibers in Sprayed on Fireproofing
Authors: Sabatini R L , Sugama Toshi , Petrakis Leonidas 
Published: July 2020

Abstract
A BNL-Grace process has been developed to chemically convert in-situ, the chrysotile fibers of sprayed-on fireproofing products to an unregulated glassy material. The effectiveness of this process has been convincingly demonstrated using Analytical Electron Microscopy and X-Ray Diffraction techniques.
Asbestos minerals were used in fireproofing materials because of their excellent physical properties including fire resistance, high tensile strength, heat and electrical insulation, and resistance to acids and alkali. But in 1975 the Environmental Protection Agency began regulating materials containing &gt; 1% asbestos.
The new in-situ BNL-Grace process, which uses a foamy solution sprayed directly onto asbestos-containing fireproofing chemically digests essentially all the asbestos fibers, transforming them into harmless materials. After treatment, the fireproofing is no longer a regulated material. The process produces essentially no waste.
Our problem was to demonstrate that all of the asbestos was converted and that the remaining materials were no longer regulated. Typical analysis methods use conventional optical and Polarized Light Microscopy (PLM) to measure and observe fibers.
Applying Microscopy in Forensic Science
Authors: Lee Henry C 
Published: July 2020

Abstract
Microscopy is of vital importance in the real world of the forensic scientist. In today's society, physical evidence is critical to the criminal justice system for the detection, investigation and prosecution of criminal acts. A trail of microscopic fibers led investigators in Atlanta to the conviction of the serial killer, Wayne Williams. Flecks of paint on a hit-run victim, analyzed microscopically, can be compared with the paint on a suspect vehicle to exclude or match it to the crime. The forensic firearms examiner compares the microscopic striations on a bullet to match it to the gun it was fired from. Microscopes are used throughout the modern forensic laboratory. They are essential in searching for evidence. They aid the examiner in identifying and comparing trace evidence. As the scales of justice symbolize forensic science, microscopes symbolize the trace evidence examiner.
Because of the variety of physical evidence, forensic scientists use several types of microscopes in their investigations.
Measurements of Fine Volcanic ASH Via Stereoscopy in the Scanning Electron Microscope
Authors: Mills OP , Rose WI , Riley CM 
Published: July 2020

Abstract
Volcanic eruptions inject tons of silicic material into the atmosphere. Large, dense material falls out within a few hours whereas fine size fractions, &lt; 10 μm radius ash, may remain airborne for weeks to months. Protection of human population centers and aircraft requires predictive atmospheric transport models. Many of these models assume the ash particles are spherical but abundant qualitative studies of ash particles demonstrate irregular shapes ranging from parachute-like bubble-wall shards to polygonal shaped mineral grains. These non-spherical shapes increase atmospheric drag. The accuracy of transport models may be improved with a better understanding of the actual shapes found in fine ash particles. Therefore, the objective of this study is to accurately determine three-dimensional shape measurements via stereoscopic methods using the scanning electron microscope.
The scanning electron microscope is an ideal imaging platform for collection of stereo pairs because of its utility in stereoscopic height measurement.
Characterization of Age Hardening in a 319 AL Alloy
Authors: Jahn R , Donlon W T , Allison J E 
Published: July 2020

Abstract
319 Al (7.2-7.7wt% Si, 3.3-3.7%Cu, 0.25-0.35%Mg, 0.4%max.Fe, 0.2-0.3%Mn, 0.25%max Zn, 0.25%max Ti) is utilized by the automotive industry for engine blocks and cylinder heads. Detailed understanding of the age hardening behavior of these types of alloys is important to optimize the processing of these components to yield the desired physical properties. Age hardening curves for temperatures between 100 and 305°C have been determined for a commercial grade 319 Al alloy having a dendrite arm spacing of 30(im. Samples for TEM were prepared by conventional grinding and dimpling followed by ion milling at 4keV at liquid nitrogen temperatures. The phases formed within the primary aluminum dendrites during age hardening were characterized by JEOL 2000FX and an OXFORD ISIS microanalysis system.
Age hardening curves for Al-Cu alloys are characterized by multiple hardening stages as shown by Silcock, et al. Figure 1 shows an example of a 150°C age hardening curve for 319 Al.
Fractographic Evaluation of Thermally Stressed Single Crystal Sapphire
Authors: Wajer SD , Cohen PH 
Published: July 2020

Abstract
Optical, video and scanning electron microscopic observations show fractographic features that are used to determine the crack propagation direction and crack origin in thermally stressed single crystal sapphire hemispherical shells. These features have been typically identified in materials with symmetrically applied stresses and simple geometries. This fractographic evaluation of sapphire is unusual because of the hemispherical geometry and complex mechanical and thermal stress conditions. Computer models predict the thermal stress response of the sapphire from fast acting asymmetrical heating patterns generated during controlled laboratory testing. These experimental tests are conducted to validate the computer model predictions. When an experimental structure fails to meet the survival limits predicted by the computer model, a fractographic evaluation is conducted to determine fracture mode and to locate the crack initiation site.
Fractured pieces are examined and photographed using a low magnification, binocular optical microscope and a high resolution video camera with digitizing capabilities.
Application of SEM, TEM and CBED Techniques for Compound Identification in Stress Corrosion Cracking Failure.
Authors: R. Caballero  , A. Quintero  
Published: July 2020

Abstract
Stress corrosion cracking has been a problem in aluminum alloys exposed to an aggressive environment under high static residual tensile stress. This work is concerned with the application of electron microscopy to investigate possible causes that led to failure through stress corrosion cracking in the aluminum alloy 5182. This alloy is commonly used for making carbonated beverage containers. The containers in this study did not experience any problem at the time of the filling. However, after humid storage periods going from a few days to a few weeks, leakage at the can ends was reported in many of them. These leaks developed from a failure referred to as aluminum can end blow out.
Figure la shows an SEM micrograph of a cross section of the score imposed on the top of the can during manufacturing. The unscored metal below the score is broken when the ring or tab is pulled out during opening.
“Real-World” Microscopy: Understanding Environment-Sensitive Behavior of Ni-Base Welds
Authors: Burke M G , Wehrer R J , Brown CM 
Published: July 2020

Abstract
Ni-base alloy welds such as EN82H weld metal are frequently employed in nuclear power applications where resistance to corrosion is required. Results of a recently reported study of the mechanical properties of EN82H welds show that this alloy is susceptible to low-temperature (∼100°C) environmental embrittlement (LTEE) in hydrogenated water. LTEE is a manifestation of hydrogen embrittlement in these alloys.1 Recent LTEE tests have demonstrated a beneficial effect of a high-temperature (∼1100°C) anneal and furnace-cool in alleviating the material's susceptibility to LTEE. Understanding the reason for the reduction in LTEE susceptibility requires detailed characterization of the microstructure so that the specific structural and compositional changes that have been induced by the solution-anneal can be identified. This study reports the results of light optical and analytical electron microscopy (AEM) characterization of the microstructures of as-fabricated and as-solution-annealed EN82H welds with the objective of providing insight into the observed LTEE behavior.
Terra Incognita: Spectra from Edges and Elements not in the EELS Atlas
Authors: Former J A , Buck E C 
Published: July 2020

Abstract
The EELS Core-Loss Atlas, like a road map, serves as an essential guide for practitioners of electron energy loss spectroscopy (EELS). Even the best maps will be incomplete, however, and one may need to plot a course by other means. Our work with materials from the nuclear fuel cycle has required new spectral lines, and even new elements, to be charted. The actinides and technetium, for instance, have important spectral features above 2 keV. The EELS technique has not often been used for detecting lines above about 2 keV because of the rapidly diminishing differential cross sections for these higher energy transitions. However, as instrumentation has progressed from scanning to parallel to CCD-array detection, statistical limitations on the high energy data have been improved by orders of magnitude. Also, in some cases, the notion of higher energy lines as “weak” is excessively pessimistic.
Incommensurate Structures in Rhenium Disilicide
Authors: Misra A , Chu F , Mitchell TE 
Published: July 2020

Abstract
The binary ReSi2 and ternary (Mo,Re)Si2 alloys are of interest due to potential applications as infrared detectors [1]. Also, Re may be a beneficial alloying element to MoSi2 which is a potential high temperature structural material [2]. A recent study of the structure of ReSi2 by X-ray diffraction (XRD) revealed an orthorhombic distortion (a= 0.3121 nm, b= 0.3139 nm and c= 0.7670 nm) from the tetragonal CI lb MoSi2 structure and a Si-deficient composition of Re4Si7 [3]. Further, a weak monoclinic distortion (β=89.87°) was also inferred from high-resolution XRD [3]. In the present investigation, the orthorhombic distortion and the Si-deficient stoichiometry were confirmed by XRD and the structure of arc-melted Re4Si7 studied by transmission electron microscopy (TEM).
A bright field (BF) TEM image and the corresponding [010] zone axis selected area diffraction pattern (SADP) are shown in Fig. 1. In addition to the fundamental reflections for tetragonal Cllb MoSi2 structure,
Defects in Nb-Cr-Ti C15 Laves Phase Alloys
Authors: Kotula P G , Carter CB , Chen K C , Thoma D J , Chu F , Mitchell T E 
Published: July 2020

Abstract
Laves-phase intermetallics are of potential use as high-temperature structural materials. NbCr2-based C15-structured alloys are of particular interest for such applications. The effect of Ti alloying on the microstucture and mechanical properties of such alloys has been investigated and it has been shown that Ti can improve the fracture toughness of the monolithic CI 5 Laves phase8 and dual-phase (bcc and CI 5) alloys. In the Nb-Cr-Ti system, there is a complete solid solution between NbCr2 and TiCr2, with a significant range of solubility of the C15 phase and a large two phase, bcc and C15, region. The initial characterization of the defect structure of an alloy of overall composition Nb10Cr75Ti15 is discussed here.
Nb10Cr75Ti15 was prepared by arc-melting the high-purity elemental metals followed by annealing at 1400°C for 120 h and then cooling at l°C/min. Specimens were prepared for observation in the TEM by cutting 3 mm discs with a coring saw, followed by dimpling and ion milling.
Microstructure of the Die-Upset Nd (Pr)-Fe-B Hard Magnets Studied by Magnetic and High Resolution Transmission Microscopy
Authors: Volkov VV , Zhu Y , Lewis LH , Welch DO 
Published: July 2020

Abstract
Magnetic properties of permanent magnets are sensitive to their microstructure. In particular, for a class of Nd(Pr)-Fe-B magnets very different coercivity and energy products may be obtained by different processing techniques. In this work we report on the preliminary results of magnetic domains (MD) structure and grain boundaries (GB) analysis of such hot-deformed Nd(Pr)-Fe-B magnets. To reveal the fine details of MD and GB interaction the experiments were carried out by the combined use of Magnetic Foucault-Fresnel Imaging and High Resolution Microscopy.
The magnets used in this study had a nominal composition Nd13.75Fe80.25B6 (I) and Pr13.75Fe80.25B6 (II) and were produced at the General Motors Research and Development Center. Buttons of the die-upset samples were prepared from overquenched ribbons using the melt-spun technique. Thin sections were cut from the buttons obtained by die-upset of the ribbons of I and II. These sections were mechanically polished and then ion milled until perforation. Electron microscopy was done using a JEM 2000FX microscope operating at 200 kV.
Stress-Induced Phase Transformations in SiC
Authors: Pirouz Pirouz 
Published: July 2020

Abstract
Tetrahedrally co-ordinated materials can undergo stress-induced structural transformations often under invariant plane strain conditions; examples of such transformations are twinning and polytypism. The structure of a tetrahedrally co-ordinated material, XY, may be considered in terms of an assembly of “normal”, Ti’and “twinned” tetrahedra, T'I’all connected to each other at their corners. In some of these materials, e.g. SiC, GaN or CdS, these corner-sharing tetrahedra may be connected to each other in different ways, giving rise to different polytypes. In this paper, a dislocation model for polytypic transformations is discussed and a few examples of stress-induced transformations are illustrated.
In general, dislocations in XY polytypes he on basal (0001) planes and are generally dissociated into “leading’ and “trailing” partial dislocations with Burgers vectors b1 and bt’ respectively. There is also good evidence that dissociated dislocations in tetrahedrally-coordinated materials belong to the glide set and move on the slip plane in a dissociated manner.
Dislocations in Ceramics
Authors: Carter C Barry 
Published: July 2020

Abstract
Of the four groups of crystal lattice defects, i.e., point defects, dislocations, interfaces and particles, dislocations are often thought to be the least important for ceramic materials. However, they not only give considerable insight into interfaces (they can be thought of as the link between point defects and interfaces), but they are becoming more important as interest grows in epitactic oxide heterostructures.
The present paper provides a review of our current understanding of dislocations in ceramics. To simplify the discussion, we can separate the task into the following sections, namely Simple oxides (MgO, ZnO etc.)Simple non-oxides (A1N, GaN, SiC, TiC, etc.)More complex binary oxides (AI2O3, Fe203, etc.)Multicomponent oxides and complex non-oxides (spinels, garnets, S13N4)Interfacial dislocations (misfit, grain boundary, etc.)
The features which are most often associated with ceramic materials are their complex structures and large unit cells. For example in bcc garnets, the smallest Burgers vector for a perfect lattice dislocation is ∼0.8nm long.
Z-Contrast Imaging of Ordered Structures in Pb(Mg1/3Nb2/3)O3 and Ba(Mg1/3Nb2/3)O3
Authors: Yan Y , Xu Z , Viehland D , Pennycook S J 
Published: July 2020

Abstract
Lead-based cubic perovskites such as Pb(B2+ 1/3B5+ 2/3)O3 (B2+ = Mg, Co, Ni, Zn; B5+ = Nb, Ta) are relaxor ferroelectrics. Localized order and disorder often occur in materials of this type. In the Pb(Mg1/3Nb2/3)O3 (PMN) family, previous studies have proposed two models, space-charge and charge-balance models. In the first model, the ordered regions carry a net negative charge [Pb(Mg1/2Nb,/2)03], while in the second model it does not carry a net charge [Pb((Mg2/3Nb1/3)1/2Nb1/2)03]. However, no direct evidence for these two models has appeared in the literature yet. In this paper we report the first direct observations of local ordering in undoped and La-doped Pb(Mg1/3Nb2/3)03, using high-resolution Z-contrast imaging.
Because the ordered structure in Ba(Mg1/3Nb2/3)03 is well known, the Z-contrast image from an ordered domain is used as a reference for this study. Fig. 1(a) shows the projection of the supercell of fully ordered Ba(Mg1/3Nb2/3)03 along the [110] direction.
Atomic Scale Structure-Property Relationships of Defects and Interfaces in Ceramics
Authors: Stemmer S , Duscher G , James E M , Ceh M , Browning ND 
Published: July 2020

Abstract
The evaluation of the two dimensional projected atom column positions around a defect or an interface in an electronic ceramic, as it has been performed in numerous examples by (quantitative) conventional high-resolution electron microscopy (HRTEM), is often not sufficient to relate the electronic properties of the material to the structure of the defect. Information about point defects (vacancies, impurity atoms), and chemistry or bonding changes associated with the defect or interface is also required. Such complete characterization is a necessity for atomic scale interfacial or defect engineering to be attained.
One instructive example where more than an image is required to understand the structure property relationships, is that of grain boundaries in Fe-doped SrTi03. Here, the different formation energies of point defects cause a charged barrier at the boundary, and a compensating space charge region around it. The sign and magnitude of the barrier depend very sensitively on the atomic scale composition and chemistry of the boundary plane.
White Lines in the Iron L2,3 Electron-Energy-Loss Spectra of Pyrite and Greigite
Authors: Cheng S C , Wilkin R T 
Published: July 2020

Abstract
The white lines on the L2,3 absorption edges of the transition metals and on the M4,5 absorption edges of the rare earth elements are the most prominent feature in electron-energy-loss spectra (EELS). The white lines of these elements have been studied and used to determine valance and coordination of atoms in various systems. Fe-O compounds with valence 2, 3 and mixed valence states, for example, have been carefully examined and characterized. However, in spite of the importance of iron sulfides in geochemistry and environmental science, the EELS data of these compounds are not available. Pyrite (FeS2) is widespread in hydrothermal ores, modern sediments, and sedimentary rocks deposited throughout the geologic record. The ferromagnetic iron sulfide greigite (Fe3S4) is another important compound. It has been recognized as a carrier of magnetic remanence in young sediments. Sedimentary greigite may be precipitated inorganically or biogenically by magnetotactic bacteria.
Improved Adhesion of the c-BN Film by the Post ION Implantation: TEM and FTIR
Authors: Sung C , Gunasekara S , Byon ES , Lee SW , Lee SR 
Published: July 2020

Abstract
Boron nitride thin films have been deposited on (100) oriented Si substrate by magnetically enhanced activated reactive evaporation technique. The build up of c-BN is normally accompanied by strong compressive stresses. When these stresses exceeds the strength of the adhesion forces at the interface, adhesion fails causing the destruction of the c-BN film. This has been one of the major limiting factors of using the c-BN films for many important industrial applications such as cutting tools and semiconductor devices.
In this experiment, the plasma immersion ion implantation has been applied to improve the adhesion of the film. The post ion implantation was conducted at several implantation energies and constant dose. The effect of ion implantation on the microstructures was investigated by Fourier Transform Infrared spectroscopy and Transmission Electron Microscopy.
Infrared characterization of c-BN film by FTIR (Fig.l) shows that the IR spectra of the specimens prepared at all energies but 72 kV have strong absorption band at 1080 cm-1 corresponding to cubic boron nitride.
Carbon-Induced UV Sensitivity in Aluminum Nitride
Authors: Berta Y , Gerhardt R A 
Published: July 2020

Abstract
Aluminum nitride, translucent, calcia-sintered and hot pressed, with its superior thermal properties has applications in high performance electronic devices such as multichip modules. In these applications, A1N is exposed to high energy electromagnetic sources which could alter its properties; for example, upon UV irradiation, thermal conductivity drops and dielectric loss increases. These observations indicate that the UV altered properties are due to the presence of impurities. The early studies concentrated primarily on oxygen doped samples, which photodarken upon UV exposure; the role of other impurities was not considered.
In the current work, we consider the role of carbon in the microstructure of two very low oxygen content (&lt; 0.3 wt %), carbon-containing samples, labeled B and E, for the ultimate purpose of 3 determining the mechanism by which carbon impurities affect the properties of A1N. Previous work on these samples correlated higher carbon content with a lower increase in the dielectric loss factor, after UV irradiation,
Microstructure and Strain Relaxation of Epitaxial SrRuO3 Films
Authors: Jiang J C , Pan X Q , Gan Q , Eom C B 
Published: July 2020

Abstract
It is widely believed that the stress in the epitaxial thin films, caused by the lattice mismatch between the thin film and substrate, has a strong influence on the properties. For example, lattice strained epitaxial thin films of SrRu03 grown on (001) SrTiO3 demonstrated magnetic and electrical properties different from those in bulk materials.1 In this paper, we report the effect of strain relaxation of the thin film on microstructure by means of transmission electron microscopy (TEM).
SrRuO3 thin film on a vicinal (001) SrTiO3, with a miscut angle 0.9° and miscut direction 5.7° away from the in-plane [100] axis, was grown by 90° off-axis sputtering. Cross-section and plan-view TEM specimens were prepared following the procedure described in Ref. 2. TEM investigations were conducted in a Philips CM 12 microscope in the EMAL at the University of Michigan.
X-ray diffraction studies of the as-grown SrRu03 thin film using a four-circle diffractometer showed that the film consists of a single [ 110]-type domain structure.
Determination of the Site Occupancy of Holmium in SrTiO3 by Alchemi
Authors: Cheng S C , Hitomi A , Randall C A 
Published: July 2020

Abstract
The perovskite structure is based upon the mineral CaTiO3, which is a pseadocubic at room temperature. The ideal structure has a twelve fold coordinate A-site, and an octahedral coordinated B-site, and the face-centered position being oxygen. The perovskites have been of commercial interest for capacitors owing to their high dielectric constants. The crystal chemistry related to the perovskite based dielectrics multilayer capacitors (MLCs) is of interest in this paper. The MLCs with base metal internal electrodes such as copper and nickel have been studied for many years. To avoid oxidation of the nickel or copper electrodes during sintering, a reducing atmosphere is necessary. However, reduced firing causes two basic problems: an increasing of conductivity of the BaTiO3, dielectrics and limitation on reliability by the migration of oxygen vacancies. The solution for the first problem is to use acceptor dopants, such as MnO and more stable oxide additives, such as CaZrO3 to increase the resistivity of the dielectrics.