bluuebunny/crossref_metadata_2025_split huggingface dataset:
Elemental Mapping of Co-Based Magnetic Recording Media: EFTEM and STEM Spectrum Imaging
Authors: Bentley J , Wittig JE , Al-Sharab JF , Evans ND 
Published: July 2020

Abstract
The optimized performance of Co(CrTaPt) thin-film longitudinal magnetic recording media (for computer hard discs) depends critically on the grain size distribution and on intergranular Cr segregation that magnetically isolates the grains. These microstructural aspects of both model and commercial media have been extensively investigated at ∽1 nm resolution with quantitative elemental mapping by energy-filtered transmission electron microscopy (EFTEM) of Cr, Co, and O, but not Ta and Pt which unfortunately are not amenable to quantitative elemental mapping by EFTEM. Procedures for data acquisition and processing have been refined in order to provide robust methods for measuring intergranular compositions for statistically significant numbers of grains. Figure 1 shows results obtained with a Gatan imaging filter (GIF) interfaced to a LaB6 Philips CM30 for a carbon-capped 25-nm-thick film of Co80Cr16Ta4 grown on a Cr underlayer. Typical acquisition parameters have been described previously. to avoid the Cr underlayer, foil thicknesses t&lt;0.2X are used, including the carbon overlayer (λ = inelastic mean free path ≌100 nm).
ELNES in Hexagonal and Cubic Boron Nitrides Evaluated with DV-Xα Method
Authors: He LL , Ye HQ , Oikawa T , Murakami Y , Shindo D 
Published: July 2020

Abstract
The hexagonal boron nitride (h-BN) exhibits a phase transformation to the cubic one (c-BN), the latter of which is well known as the second hardest material so far, under high pressure. This transformation is accompanied not only by the geometrical change in the crystal structure, e.g. stacking sequence of the close-packed planes, but also change in the chemical bonding from sp2 to sp3 characters. Electron energy-loss spectroscopy (EELS) is a hopeful way to characterize the state of bonding around the phase boundaries etc., and will provide rich information on the transformation mechanism. However, the energy-loss near-edge structure (ELNES) is rather sensitive to the orientation of specimens, if the structure is anisotropic as in the case of h-BN. This is sometimes obstructive to evaluations of ELNES, whereas a detailed investigation on this peculiar effect is needed. in the present work, the angular dependence of ELNES in h-BN was extensively studied by both calculations with DV-Xα (Discrete Variational X α cluster) method and experiments, beside investigations of the c-BN.
Dielectric Properties of ZrC by Electron Energy Loss Spectroscopy
Authors: Espinosa-Magaña F , Duarte-Moller A , Martínez-Sánchez R , Paraguay-Delgado F 
Published: July 2020

Abstract
Zirconium carbide belongs to the group of refractory compounds having NaCl structure with high chemical inertness and melting point, characteristics that have made these materials to play a prominent role as hard coatings and these properties are closely related to their electronic structure. The electronic configuration of ZrC is: (Xe) 5d2 6s2, one s electron being able to be promoted to a d orbital forming four equivalent sd3 hybrid orbitals, favoring covalent bonds maintaining, however, a percentage in ionic character of about 30%.
Some attention has been paid in the last two decades in studying the optical properties of transition metal carbides and nitrides by electron energy loss spectroscopy (EELS), being TiC and TiN the most extensively reported.
In this work the optical constants of commercial powder ZrC were obtained using a Gatan Parallel Detection Electron spectrometer (model 766) attached to the CM-200 transmission electron microscope (TEM).
Applications of Multi-Variate Statistical Analysis of Spectrum Images to Microelectronic Devices
Authors: Bruley J 
Published: July 2020

Abstract
It is not uncommon for an electrical failure in a microelectronic device to be traced back to an individual resistive contact, such as a W contact lined by TiN to the underlying metal silicide [1]. Identifying the root cause of the defective cell then requires the capability of extracting interfacial chemistry and microstructure with near atomic resolution, which is achieved by recording EELS and EDX data either along 1-d lines or from 2-d arrays. EELS data are characterized by intrinsically low signal-to-background ratios and plural inelastic-scattering effects, which presents a challenge to the reliability of the methods used to extract quantitative information from a spectrum image. Commercially available software packages by Emispec and Gatan currently provide routines for power-law or polynomial background fits and allow the net counts under peaks or edges to be determined from each pixel. in both cases each spectrum in the series is processed in the same manner.
Analysis of Biological Structures by Electron Energy Loss Spectroscopy and Imaging
Authors: Leapman RD , Andrews SB 
Published: July 2020

Abstract
As techniques for electron energy-loss spectroscopy (EELS) reach a higher degree of optimization, detection limits for analyzing biological structures are approaching those predicted by theory. in favorable specimens, single atom detection is predicted for elemental maps acquired by means of the scanning transmission electron microscope (STEM) equipped with a field emission source, paralleldetection EELS and a spectrum-imaging system. to obtain such results, the electron detector should have a detective quantum efficiency close to unity and a well behaved point-spread function; such design features are now available with a cooled charge-couple device (CCD) array. The energy-filtering transmission electron microscope (EFTEM) provides a complementary approach to mapping elements occurring at higher concentrations but distributed over larger regions of the specimen. Use of an optimized CCD detector in the EFTEM now enables accurate quantitation in addition to high analytical sensitivity, albeit not at the single atom level.
Advances in C. elegans Specimen Preparation for TEM Using Microwave and Fast Freeze Techniques
Authors: Hall DH , Starich T , Shaw J , Gobel V , Fleming J , Norris C , Huang C-c 
Published: July 2020

Abstract
The nematode C. elegans is a simple model for genetic studies of cell and tissue development. There is a need to improve the preservation of embryonic and early larval stages, during which nematode tissues elaborate and separate. However, these stages are particularly resistant to fixation and embedment due an impenetrable eggshell and larval cuticle. Their small size at these ages precludes mechanical cutting, which has been used successfully for immersion fixation of older stages. Here we compare the quality of preservation under three rather different regimes: using laserholes to permeabilize the eggshell during the primary fixation step, using microwave energy to enhance the first fixation step, or using fast freezing and freeze substitution to circumvent the standard immersion procedure. Vancoppenolle et al (2000) have recently demonstrated very good results through enzymatic weakening of the eggshell prior to immersion fixation. Their data are comparable to what we achieve by either the laserhole or microwave methods.
Light and Electron Microscope Immunocytochemistry in Freeze-Substituted Plant and Fungal Cells
Authors: Czymmek KJ , Bourett TM , Howard RJ 
Published: July 2020

Abstract
In efforts to better understand the cell biology of fungi and their pathogenic interactions with plants, we have pursued the use of cryo-preparative techniques for specimen preservation and immunocytochemistry at the light and electron microscope level. The chemically diverse composition of plant and fungal walls has proven very challenging for immunofluorescence using confocal microscopy. Typically, to allow probe access in these organisms, immunolabeling has required sectioning or enzymatic digestion of cell walls. The ideal method would preserve the spatial fidelity and antigenicity of the target molecule as well as maintain the integrity of the surrounding tissue. Our early work using methacrylate de-embedment, as described for sectioned plant material, was very effective for freeze-substituted fungi. Further improvements, using a combination of slow freezing and freeze-substitution followed by methacrylate de-embedment, permitted whole mount fluorescence antibody labeling of a variety of phylogenetically diverse fungi without enzymatic digestion or sectioning (Fig.l).
Cryo-Fixation and Gene Product Localization in Fungi
Authors: Bourett TM , Duncan KE , Czymmek KJ , Sweigard JA , Dezwaan TM , Howard RJ 
Published: July 2020

Abstract
There are many strategies for documenting the distribution of gene products or other molecules within cells or tissues. Depending on the required information, techniques can range from cell fractionation to methods that employ electron microscopy: some preclude examination of living cells, and thus can not provide dynamic temporal information. Time sequence data are paramount when gene expression is transient, as is often the case during fungal-pathogen plant-host interactions. Fluorescent dyes and protein tags (e.g., green fluorescent protein, GFP) allow monitoring of specific molecules, organelles or cells over time, for simultaneous recording of both spatial and temporal information. in addition, fluorescent markers are amenable to powerful 3-D analysis using confocal or multi-photon imaging methods. We have achieved good expression of fluorescent proteins in the fungal blast pathogen Magnaporthe grisea, and have generated a functional fusion protein between GFP and P-tubulin (Figs. 1,2).
Investigation of Carbonaceous Phases in Interplanetary Dust Particles by Acid Dissolution of Microtomed Thin-Sections
Authors: Joswiak D J , Brownlee D E 
Published: July 2020

Abstract
Interplanetary dust particles (IDPs) collected from the stratosphere are grains of cosmic dust delivered from asteroids and comets. IDPs are composed of complex mixtures of carbon, silicate glass and submicron to nanometer-sized minerals including Fe-Mg silicates, Fe-Ni sulfides, oxides and metal. Bulk SEM and detailed TEM investigations of stratospheric IDPs in the size range of 5 - 15 μm have shown that many IDPs have remarkably high concentrations of carbon - essentially the highest carbon abundances of any known extraterrestrial materials - and often this carbon is intermixed at the nanometer scale with other constituent phases. in order to investigate the properties, occurrence and spatial distribution of carbon in IDPs, we have developed a unique aciddissolution technique using standard microtomed thin-sections to remove the silicate and oxide fractions, thereby leaving a residue primarily of carbon and Fe-Ni sulfides. This technique causes no damage to the delicate microtomed sections or TEM grid and dramatically minimizes the quantity of acids required for etching.
TEM Study of the Effect of the Sapphire Substrate Surface Orientation on the Microstructure of Tin Dioxide Films
Authors: Dominguez J E , Fu L , Pan X Q 
Published: July 2020

Abstract
Tin dioxide (SnO2) has been extensively studied and used as gas sensors to detect toxic gases such as CO, NOxand flammable gases like H2.[l] Recently, considerable researches have focused on thin film sensors due to their high performance as well as their integration compatibility with semiconductor technology for making microsensors and sensor arrays. [2] The performance of thin film sensors is remarkably influenced by the way they were fabricated.[3] Among various deposition techniques, pulsed laser deposition (PLD) has shown great prominence in the deposition of a wide variety of oxide thin film materials such as high Tc superconductors, semiconductors and dielectrics. in this work we present our experimental results on tin dioxide films deposited using pulsed laser ablation on sapphire (α -Al2O3) substrates with different surface orientations.
Tin oxide films with a thickness of 100 nm were deposited on the (1012) and (0001) sapphire by pulsed laser ablation of ceramic SnO2 targets.
Misfit relaxation in SrTiO3/SrRuO3 bilayer films on LaA1O3(100) substrates
Authors: Wu JS , Jia CL , Urban K , Hao JH , Xi XX 
Published: July 2020

Abstract
Besides perfect dislocations, partial dislocations were proposed as effective means for misfit relaxation in the heretostructure system [1]. The microstructure of SrRuO3 films on SrTiO3 and LaA1O3 substrates have been studied. While misfit dislocations could be hardly found at the SrTiO3/SrRuO3 interface [2], high density of defects was observed in the SrRuO3/LaA1O3 interfaces [3]. in this paper, we report the high-resolution electron microscopy study of the SrTiO3/SrRuO3 bilayer films on (100) LaA1O3 substrates. The emphasis is focused on the means of misfit relaxation at the two interfaces.
Figure 1(a) is a low magnification cross-sectional image of a two-layer SrTiO3/SrRuO3 film on LaA1O3 taken along the [110] direction of the substrate. A high density of defects were observed along the SrRuO3/LaA1O3 interface. Figure 1(b) is a quarter of a superposed electron diffraction pattern (EDP) from the SrTiO3/SrRuO3 interface area, while fig. 1(c) is from the SrRuO3/LaA1O3 interface area.
Characterization of Magnetron Assisted Pulsed Laser Deposited ZrO2-Au Composite Films Using TEM and EDS
Authors: Hu JJ , Voevodin AA , Zabinski JS 
Published: July 2020

Abstract
Microstructurally engineered oxide coatings have good potential as lubricants for aerospace applications over a wide range of environmental conditions1. Using composite microstructures, wear rates and friction coefficients may be reduced compared to monolithic coatings. Here, we report the characterization of ZrO2-Au composite coatings as new candidate lubricants. Au is added to ZrO2 to reduce friction and improve toughness. The composite films were grown on steel and silicon disks at room temperature (RT) by pulsed laser ablation of a ZrO2/5 wt. % Y2O3 target, with simultaneous operation of a magnetron source to add Au. The laser beam was operated at 250mJ, 40 Hz, and the magnetron was operated at 1.5-3.5 W cm-2 in 2.7 Pa argon. Varying the magnetron power produced coatings with different concentrations of Au. The coatings were prepared for transmission electron microscope (TEM) analysis by tripod polishing and ion milling on a cold stage.
In-Situ Growth and Polygonization of Epitaxial Passive Oxide Films on Nanoparticles of Iron
Authors: Fung KK , Zhang XX , Kwok YS , Qin Boxiong 
Published: July 2020

Abstract
Over the years, the study of the oxidation of nanoparticles of iron by transmission electron microscopy (TEM), Mossbauer spectroscopy and X-ray diffraction has established that nanoparticles of iron have a core-shell morphology in which the iron core is enclosed by shell of polycrystalline shell of ultrasmall γ-Fe2O3 and Fe3O4 crystallites. Recently, passivated nanoparticles of iron prepared by gas condensation of plasma evaporated vapor in Tianjin University exhibit remarkable resistance to further oxidation and corrosion in air and water. We have showed by TEM that these nanoparticles of iron are protected by a 4 nm epitaxial shell of γ-Fe2O3. The epitaxial orientation relationship, established by convergent beam electron diffraction from a nanoparticle, is as follows:

The [001] diffraction pattern of the oxide is rotated by 45° about a cubic axis relative to that of iron.
Analyses of The Eutectoid Phase Transformation in Complex Ds Nb-Silicide In-Situ Composites
Authors: Sitzman SD , Bewlay BP 
Published: July 2020

Abstract
In-situ composites based on (Nb) and Nb silicides, such as Nb5Si3 (tI32 crystal structure) and Nb3Si (tP32 crystal structure), are being investigated for revolutionary high-temperature structural applications [1,2]. The use of Hf and Ti alloying additions to these silicides has also been examined; in these systems Nb5Si3 has also been observed with the hP16 structure. The present paper describes EBSD analyses of a directionally solidified (DS) Nb-silicide based composite that experienced a eutectoid transformation. The composites were directionally solidified using the Czochralski method as described previously [1]. The composites were creep tested at 1200°C for 24 hours. Microstructure and microtexture characterization were performed using scanning electron microscopy, and electron backscatter diffraction pattern analysis (EBSD).
The microstructure of a composite directionally solidified from a Nb-12.5Hf-33Ti-16Si alloy is shown in Figure 1. in the as-DS condition the microstructure consisted of primary (Nb)3Si dendrites and coarse (Nb)3Si-(Nb) two-phase cells.
Inclusion Characterization and Bubble Evolution in Doped Molybdenum Wire
Authors: Iorio LE , Larsen M , Bewlay BP 
Published: July 2020

Abstract
Previous studies on aluminum-potassium-silicon (AKS) doped tungsten wire have shown that the dispersion which provides the interlocking grain structure in recrystallized tungsten wire is bubbles of elemental potassium. However, there is little previous work on the K-containing dispersion in doped Mo. This paper will describe analyses of doped Mo.
The creation of dopant inclusions in Mo powder and generation of K bubbles in doped Mo wire both prior to and following various heat treatments has been studied. The effect of doping Mo with K, Al and Si is to increase the recrystallization temperature of the Mo and to produce a microstructure of coarse, interlocking grains after recrystallization.
Mo wire is produced in a similar manner to AKS doped tungsten, however lower processing temperatures are typically used in the production of Mo wire. The dopants are added to Mo oxide powder as potassium silicate and aluminum chloride.
The Geometric Compatibility Factor Determining Brittle Crack Propagation Across Boundary in Bainitic Low Alloy Steels
Authors: Oh Yong-Jun , Kim Min-Chul , Hong Jun-Hwa 
Published: July 2020

Abstract
Boundary properties between two adjacent grains with different crystallographic orientation relation are important factors in deciding the mechanical properties of materials. in our previous reports, we introduced the geometric compatibility equation as a factor determining the brittle crack propagation condition into the adjacent grain in banitic low alloy steel as follows:
M = cos α · cos θ
where α is the angle between crack normal in the cracked grain-I and normal to (001) plane in the adjacent grain-II and θ is the angle between normal to (001) plane in the grain II and loading axis.(see FIG. 1) Higher M gives greater possibility to the crack propagation. The geometric compatibility factor (M) could be easily calculated from the crystallographic data obtained from Electron Backscatter Diffraction (EBSD) analysis, and successfully predicted actual crack propagation plane. We also found that there was a critical M value to arrest the brittle crack propagation at the boundaries.
RMS Strain 〈ε〉½ Variation Vs Grain Refining During Annealing of Co50Ti50 Synthesized By AM-SPS
Authors: Martínez-Sánchez R , Béjar-Gómez L , Espinosa-Magaña F , Cabañas-Moreno JG , Duarte Moller A , Diaz de la Torre S 
Published: July 2020

Abstract
The mechanical alloying (MA) process has been probed to be an effective method to conveniently develop materials with novel structures. The products of MA can be processed by conventional powder metallurgy routes for further consolidation. However, the novel features conferred to the powders, such as fine crystal size and chemical homogeneity can be lost during sintering operations, due to the high chemical activity of some of the synthesized phases. The Spark Plasma Sintering (SPS) process is an alternative route to obtain highly dense MA′ed products while retaining these novel microstructures, including a metastable state. Advantages of the SPS process over conventional sintering processes are the fast heating and cooling rates, and the high pressure applied. Combining these two material processing techniques (MA and SPS) it is possible to obtain materials with interesting (far from equilibrium) microstructures. Co-Ti alloys were obtained by MA and SPS, as described in related publications.
Initial Oxidation Kinetics of Copper (110) Thin Films As Investigated By IN SITU UHV-TEM
Authors: Zhou Guang-Wen , D.Bharadwaj Mridula , C.Yang Judith 
Published: July 2020

Abstract
In the study of metal oxidation, there is a wide gap between information provided by surface science methods and that provided by bulk oxidation studies. The former have mostly examined the adsorption of up to ∽1 monolayer (ML) of oxygen on the metal surface, where as both low and high temperature bulk oxidation studies have mainly focused on the growth of an oxide layer at the later stages of oxidation. Hence, we are visualizing the initial oxidation stages of a model metal system by in situ ultra-high vacuum (UHV) transmission electron microscopy (TEM), where the surfaces are atomically clean, in order to gain new understanding of these ambiguous stages of oxidation. We have previously studied the growth of Cu2O islands during initial oxidation of Cu(100) film. We are presently investigating the initial stages of Cu(110) oxidation, from 10−4 Torr O2 to atmospheric pressures and temperature range from room temperature to 700 °C.
In-Situ Study of NiO Growth on Textured Nickel Tape Using Environmental Scanning Electron Microscope (ESEM) and Hot Stage
Authors: Akin Y , Goddard RE , Sigmund W , Hascicek YS 
Published: July 2020

Abstract
Deposition of highly textured ReBa2Cu3O7−δ (RBCO) films on metallic substrates requires a buffer layer to prevent chemical reactions, reduce lattice mismatch between metallic substrate and superconducting film layer, and to prevent diffusion of metal atoms into the superconductor film. Nickel tapes are bi-axially textured by cold rolling and annealing at appropriate temperature (RABiTS) for epitaxial growth of YBa2Cu3O7−δ (YBCO) films. As buffer layers, several oxide thin films and then YBCO were coated on bi-axially textured nickel tapes by dip coating sol-gel process. Biaxially oriented NiO on the cube-textured nickel tape by a process named Surface-Oxidation- Epitaxy (SEO) has been introduced as an alternative buffer layer. in this work we have studied in situ growth of nickel oxide by ESEM and hot stage.
Representative cold rolled nickel tape (99.999%) was annealed in an electric furnace under 4% hydrogen-96% argon gas mixture at 1050°C to get bi-axially textured nickel tape.
TEM Characterization of Corrosion Initiation in Passive Films
Authors: Elswick D , Hren J , Kotula P , Missert N , Wall F 
Published: July 2020

Abstract
This research program is intended to develop new insight into the mechanisms of localized corrosion initiation in passive metals through unique approaches based on examining corrosion initiation on needle-shaped samples similar to field emitter tips. Samples with this geometry allow localization of corrosion initiation to the tip itself and therefore pit initiation can be confined to a small lateral area. Local electric fields can also be controlled, thus permitting damage to be confined in the passive over layer, and characterized before pit initiation.
High purity Al wire was used for the initial studies. Wire shaped specimens were electropolished in a 20 % perchloric in methyl alcohol solution at -30°C to obtain the fine needle geometry. The resultant tip radii ranged from 40 to 150 nm with no further sample prep needed and without the presence of artifacts.A custom-designed TEM holder for a Philips CM30 was fabricated, which allowed the needles to be characterized by TEM both prior to and after experiments.