bluuebunny/crossref_metadata_2025_split huggingface dataset:
“Y Contrast” of Single Shell Carbon Nanotubes: Determination Of Young’s Modulus by Observing Thermal Vibrations
Authors: Treacy MMJ , Krishnan A , Dujardin E , Yianilos PN , Ebbesen TW 
Published: July 2020

Abstract
Single shell carbon nanotubes are members of the Fullerene family of carbon molecules. Typically, single shell carbon nanotubes measure about 0.7 — 3 nm in diameter and are usually several microns in length. Structurally, they can be thought of as narrow graphite sheets that have been bent around the long axis and joined at opposite edges to form long seamless hollow shells of carbon. Typically, a hemispheroidal cap that contains exactly six 5-rings terminates each end, as shown in Figure 1.
Graphite is known to have an in-plane elastic modulus of ∼1 TPa, one of the highest values known. Consequently, it is expected that single shell nanotubes should be very stiff — a fact that makes them potentially useful in fiber reinforced composites. However, because of their small size, it is impractical to measure their stiffness directly by conventional mechanical means. Recently, we demonstrated that thermal vibrations in freestanding multiwalled nanotubes could be used to estimate their stiffness [1].
A Big Tripod Polisher; 16 Years of Imaging Surfaes
Authors: Marks LD 
Published: July 2020

Abstract
Electron Microscopy of surfaces has always been a topic for a few stubborn souls. In addition to the standard headaches of electron microscopes (maintenance, breakdown) one has to handle the additional complications of maintaining a clean enough vacuum to make the results mean anything. (Without vacuum control the structures observed may be due to the contaminants, and hence meaningless.) To complicate things further, in addition to conventional ex-situ sample preparation one has to clean and equilibriate the surface while still retaining thin enough regions for useful study. The final step is to work out which techniques provide surface information and learn how to exploit them. It is appropriate to look at some of the key elements that are needed.
Sample Handling: The key to success with surfaces is not really the microscopy, but instead the sample treatment. The first crucial element is control over the sputter cleaning process.(While simple heating would be less damaging, if one wants to look at something other than silicon sputter cleaning is a must.)
Diffraction Channeling and the Production of Secondary Excitation
Authors: Pennycook SJ 
Published: July 2020

Abstract
The pivotal role played by Archie Howie in the development of many areas of electron microscopy is universary acknowledged.Here I would like to highlight his contribution to the quantitative description of secondary excitations, which was an important influence on the development of Z-contrast imaging in zone-axis crystals. Secondary excitations are those such as x-ray emission which occur following a primary scattering event, in this case excitation of inner shell electrons. The first important concept to be realized by Archie was that dynamical diffraction and channeling are different manifestations of the same physical effect, namely, the multiple scattering of electrons within a crystal. Second was the realization that processes which are localized within the unit cell will show a dependence on diffraction conditions, such as incident beam orientation, and could therefore be described quantitatively using dynamical diffraction theory. Precisely the same theory was used to describe the orientation dependence of cathodoluminescence
The development of the STEM for high resolution imaging was of course due primarily to Crewe and coworkers, with an annular detector to allow efficient detection of elastic scattering over a wide angular range.
Investigating the Effect of As and Te Passivation on the MBE Growth of Cdte (111) On Si (111) Substrates
Authors: Xin Y , Rujirawat S , Brill G , Browning ND , Pennycook SJ , Sivananthan S , Sporken R 
Published: July 2020

Abstract
The epitaxial growth of CdTe on Si is currently being investigated as a means of generating an alternative substrate for the subsequent growth and processing of HgCdTe based infrared detecting devices. The most favorable orientation for the growth of high-quality HgCdTe is CdTe (111)B, which has been demonstrated to be grown on miscut Si (001) substrates with very high quality. However, twinning islands and multiple domains are present at the nucleation stage, which has a detrimental effect on the device properties.
An alternative approach, which has the potential to overcome the multiple domain problems in the nucleation stage, is to grow CdTe (111) B on Si (111) substrates. However, previous reports have shown that the direct growth of CdTe onto Si (111) results in an A-polarity for the films. In an attempt to overcome this limitation, passivation of the substrate surface has been investigated.
TEM Study of Short-Range-Order in Zirconolite Induced by High Temperature Ion Irradiation
Authors: Wang S X , Wang L M , Ewing R C 
Published: July 2020

Abstract
Zirconolite (CaZrTi207) is an important phase proposed for high level nuclear waste immobilization. Zirconolite was irradiated by 1 MeV Kr+ at various temperatures. At room temperature, zirconolite became amorphous after a dose of 7x1014 ions/cm2.1 Amorphization dose increased with temperature due to thermal annealing. The critical temperature, above which amorphization does not occur, was estimated to be 654 K. During the low temperature irradiation (&lt;654 K), concurrent with amorphization, zirconolite transformed from a monoclinic structure to the cubic pyrochlore structure and then to the fluorite substructure. The structural change is due to the disordering between cations and between oxygen and oxygen vacancies.
After an irradiation at 673 K to a dose of 3.6x1015 ions/cm, the zirconolite samples remained crystalline. The diffraction pattern consists of strong maxima from the fluorite structure and diffuse maxima surrounding the Bragg positions of the pyrochlore superlattice (FIG. 1). Diffuse scattering patterns have been reported in other phases, and were generally attributed to the shortrange- order (SRO) domains.
Nanoscale Lead Inclusions in Silicon
Authors: Johnson E , Johansen A , Touboltsev VS , Sarholt L , Dahmen U 
Published: July 2020

Abstract
TEM analyses of Si implanted with immiscible elements have shown that the implanted species characteristically segregate to form nanoscale inclusions in the amorphous Si matrix. Subsequen annealing induced recrystallization was found to lead to simultaneous removal of nearly all of the implanted species, explained in terms of stress-induced trapping of the implanted atoms at the amc phous/crystalline interface as it progresses towards the surface.
The solubility of Pb in Si is negligible, and it has previously been shown-that elemental nanoscale inclusions can be formed in Si either by ion implantation at elevated temperature or by rapid solidi cation. In the present work single crystals of &lt;110&gt; Si have been implanted with 80 keV Pb+ k at 300K, 625K and 925K respectively. The implanted fluence was 8-1019 m−2 corresponding to an average concentration of about 3 at.%. Combined TEM and RBS/channeling analysis showed that implantations at 300 K and 625 K induced amorphization of the implanted layer with dense distributions of nanoscale lead inclusions embedded in the amorphous silicon matrix (fig. 1).
Relationship Between High-Strain-Rate Superplasticity and Interface Microstructure in Aluminum Alloy Composites
Authors: Koike J , Sickafus KE , Mitchell TE 
Published: July 2020

Abstract
The Al alloy composites reinforced with Si3N4 or SiC have been reported to exhibit superplasticity at high strain rate of faster than 1x10−2 s−1. It has been shown in many aluminum alloy composites that the optimum superplastic temperature coincides with an incipient melting temperature. The coincidence suggests a contribution of the liquid phase to the superplasticity mechanism. This paper shows a direct evidence of partial melting along matrix grain boundaries and matrix-reinforcement interfaces. Based on the obtained results, the role of the liquid phase in the high-strain-rate superplasticity is discussed.
The sample was Al-Mg (5052) alloy reinforced with 20vol% Si3,N4 particles, fabricated by a powder metallurgy process. The sample showed an excellent superplasticity under the conditions given in Table 1. Partial melting was confirmed to occur at 821 K by differentail scanning calorimetry. The microstructural changes during heating were observed in situ by TEM using a heating stage. The structure of interfaces and grain boundaries was observed by HREM. Chemical analysis was performed with EDS attached to VG-STEM.
Characterization of Nanoporous TiO2 Membranes Used as Electrodes for Injection Solar Cells
Authors: Su DS , Bloeck U , Meißner B , Willig F , Giersig M 
Published: July 2020

Abstract
High efficiency solar cells require large surface layers as acceptor [1], Nanoporous titanium dioxide film is an optimun choice for that purpose. For instance, porous titanium dioxide film of one micrometer thickness, prepared by colloidal chemistry, has a porous surface whose area is 100 times larger than the surface of a compact planar film. Obviously, accessibility to surface and crystal phase of the titanium dioxide are of prime importance. In this work, we characterize nanoporous titanium dioxide membranes on Si substrate by means of high-resolution transmission electron microscopy and electron diffraction.
Colloidal TiO2 sols were prepared by a wet chemical method [2]. The resulting colloidal TiO2 sol was autoclaved in a titanium autoclave for 12h at 230°C. A portion of the autoclaved sol was concentrated under vacuum at 30°C until a concentration of 20% TiO2 (by weight) was reached. 40% (by weight of Ti02) carbowax was added to this paste and stirred over night at room temperature.
Preparation of Silicon Oxide Nanostructures Using Anodic Alumina as Templates
Authors: Zhang Ming , Bando Y , Wada K , Kurashima K 
Published: July 2020

Abstract
There is currently an intensive effort to develop large-scale semiconductor nanowire or nanotube materials, such as Si and silicon oxide SiOx (l&lt;x&lt;2), with the uniform wide range of sizes up to 30nm, which would open us new opportunities in semiconductor and catalysis industries but is difficult to achieve at present. Up to our knowledge, the detailed study on macroscopic synthesis of aligned silicon oxide nanostructures with about 30nm diameter has not been carried on yet.
The ordered nanochannel-array anodic alumina were prepared via the anodization of aluminum textured pattern on the surface in a 3% oxalic acidic solution under the constant-voltage condition. It is about 6 μm and contains ordered cylindrical pores with the uniform diameter of 20-30nm and almost perpendicular to the film surface. The aligned silicon oxide nanostructures were prepared on this anodic alumina using a sol-gel method.
For sol aged at room temperature and dipped for lmin., nanowires are formed in a shorter period of aging time; while nanotubes are synthesized in a longer time (above 23 days).
Double Length-Scale Ordered Nanoporous Silica
Authors: Yin JS , Wang ZL 
Published: July 2020

Abstract
Ordered assembly of hollow structures of silica and carbon have drawn much attention recently because of their applications in low-loss dielectrics, catalysis, filtering and photonics. The structure is ordered on the length-scale of the template spheres and the pore sizes are in submicron to micron range. Alternatively, ordered porous silica with much smaller pore sizes in nanosize range (&lt; 30 nm), produced deliberately by introducing surfactant, has also been processed, in which the porosity is created by co-polymers. In this research, a new silica nanostructure with double length-scale ordered porosities was processed, one being at the submicron scale of hollow spheres created by a template of polystyrene (PS), and the other at nano-scale created by self-assembled co-polymers.
Typical processing route includes three steps. Firstly, the ordered template of PS was created. The as-received PS with mean particle size of 203 nm was used as the raw material.
The Characterization and Phase Transformation in Iron Oxides
Authors: Liao KC 
Published: July 2020

Abstract
In the processing of sheet steel, slabs are normally heated in a reheat furnace in the temperature range of 1200° -1300° C, extracted, hot rolled on a hot strip mill (HSM) and further processed. Because of the high operating temperature and the availability of oxygen, the steel surface is usually severely oxidized. The furnace scale could be a few millimeters thick. Abnormally thick scale may not be easily removed by high-pressure water sprays at the HSM. Rolled-in scale can contribute to underpickling and potentially result in the generation of steel surface defects.
Furnace scale typically consists of three oxide layers, Fe2O3 (hematite) on the outside surface, Fe3O4 (magnetite) in the middle and FeO1+x (wustite) next to the steel substrate. An example is shown in Figure 1. The three oxide layers are identified by H (hematite), M (magnetite) and W (wustite). Furnace scale samples of low carbon steel have been analyzed via x-ray diffraction (XRD) and optical metallography in order to characterize the scale.
Enhancement of SEM/EDS Analysis Using FIB Sample Preparation
Authors: Vartuli CB , Stevie FA , Bindell JB , Shofner TL , Purcell BM 
Published: July 2020

Abstract
Scanning Electron Microscopy/Energy Dispersive Spectroscopy (SEM/EDS) has become less useful for semiconductor samples as feature dimensions decrease. It has become increasingly difficult to get sufficient signal from small features because of the large interaction volume of the primary beam. As the interaction volume is dependent on the accelerating energy of the primary electron beam, decreasing the accelerating voltage will decrease the interaction volume. This increases the percentage of signal from the feature of interest, but also lowers the number of peaks available for interpretation, reducing the sensitivity of the analysis. Several elements commonly used in the fabrication of semiconductors have overlapping peaks at lower energies, and the ability to distinguish between them is lost at low accelerating energies. It is possible to modify samples using Focused Ion Beam (FIB) to improve EDS resolution without decreasing the accelerating voltage.
The samples were prepared in an FIE 800 FIB and imaged in an Hitachi S-4700 SEM.
In-Situ Transformation of a Zinc Tem Lift-Out Specimen
Authors: Prenitzer BI , Collins S , Giannuzzi L A 
Published: July 2020

Abstract
The focused ion beam (FIB) lift out (LO) technique has been used to prepare transmission electron microscopy (TEM) specimens from individual Zn powder particles [1]. The Zn microstructure observed by TEM was compared to the Zn microstructure analyzed by traditional metallographic preparation techniques. It was concluded that the Ga focused ion milling produced no apparent microstructural damage to the Zn [1]. A low magnification TEM image of the FIB prepared Zn specimen obtained from a Philips EM430 operating at 300 KeV is shown in figure la.
The Zn FIB LO specimen was then processed in a plasma cleaner. After subjecting the Zn specimen to the plasma cleaning operation, the specimen was observed in a Philips EM400 operating at 120 KeV. The Zn specimen completely transformed during in situTEM observation at 120 KeV. The specimen was then subsequently observed in an EM430 to analyze the transformed Zn at 300 KeV.
Characterization of Thin Films on Oxide Using a Unique Tem Specimen Preparation Process
Authors: Lam Lawrence K , Ast Dieter G 
Published: July 2020

Abstract
Transmission Electron Microscopy technique is a powerful tool to examine microstructures. However, the specimen preparation process usually requires tedious and careful cutting and lapping. In this paper, we present a TEM specimen preparation process which is simple, requires about one hour, and allows specific areas of patterned films deposited on silicon dioxide to be examined. The sample consisted of three thin film layers deposited on a Corning 1737 glass substrate. The top layer was 1000 A thick, low temperature oxide; the middle layer, 1000 A thick; amorphous silicon; the bottom layer, 1000 A thick, low temperature oxide. The top oxide layer was patterned to contain a square array of 10 × l0um openings, with a 100 um center to center spacing. A thin nickel layer was the evaporated, and the specimen was heated to form nickel silicide in the 10 × 10 um areas where Ni and Si were in contact.
Synthesis of Electron Energy Loss Spectra and Application to Quantifying Detection Limits in Materials Science
Authors: Menon N K , Krivanek O L , Natusch M K H 
Published: July 2020

Abstract
Electron energy loss spectroscopy (EELS) is a powerful microanalytical tool that can be used to characterize the composition and other properties of a wide range of materials. The compositional information is retrievable from the pattern of edges displayed in the energy-loss spectrum [1]. Under favorable experimental conditions, concentrations below 1000 ppm of many different elements can be detected on a nanometer scale [2].
The minimum detectable mass (MDM) and the minimum detectable mass fraction (MDF) attainable in practice depend on many parameters (sample thickness, incident beam convergence / acceptance angles, primary energy, electron dose, probe size, detector efficiency, etc.), and there are no easy rules that can be used to predict them. For instance, a minority element that gives rise to an edge situated at an energy just lower than a major edge due to a principal constituent is much easier to detect than a minority element that gives rise to an edge just above the major edge.
Two-dimensional carrier profiling of advanced sub-micron silicon devices using Scanning Capacitance Microscopy
Authors: Konkar Atul A , Chen Wei , Noehring Kari 
Published: July 2020

Abstract
With the continuing push for reduction in the device dimensions into the deep sub-u,m dimensions, the critical need for physical and electrical characterization on this sub-μ,m scale is evident. The National Technology Roadmap has identified need for two-dimensional (2D) dopant/carrier profiling with a spatial resolution of 10 nm. Though current techniques used for dopant profiling such as secondary ion mass spectroscopy (SIMS) and spreading resistance profiling (SRP) have a high sensitivity, these offer good resolution only in the depth direction. The spatial resolution in the lateral direction in these techniques is limited to several tens or hundreds of microns. To acheieve the required lateral spatial resolution different scanning probe based techniques have been explored. One of the most promising of these class of techniques is scanning capacitance microscopy (SCM). In SCM a conductive atomic force microscope (AFM) probe tip is scanned across the surface and simultaneously an a.c. bias is applied between the tip and the sample.
Chemical Imaging With a Scanning Probe Microscope
Authors: Kossakovski Dmitri A , Baldeschwieler John D , Beauchamp J L 
Published: July 2020

Abstract
Scanning Probe Microscopy (SPM) is a superb tool for topographical analysis of samples. However, traditional varieties of SPM such as Atomic Force, Scanning Tunneling and Near-field Scanning Optical Microscopy have limited chemical contrast capability. Recently, several advanced techniques have been reported which provide chemical information in addition to topographical data. All these methods derive advantage from combinations of scanning probe methodologies and some other, chemically sensitive technique. Examples of such approaches are: Near-field Scanning Raman Imaging, Near-field Scanning Infrared Microscopy and mass spectrometric analysis with laser ablation through fiber probes.
In this contribution we report the development of a new method in this family of chemically sensitive scanning probe techniques: Laser Induced Breakdown Spectroscopy with Shear Force Microscopy, LIBS-SFM. Traditional LIBS experiments involve focusing a pulsed laser beam onto the sample and observing optical emission from the plasma formed in the ablation area. The emissions are mostly in the UV/visible range, and the signal is due to electronic transitions in excited atoms and ions in the plasma plume. The spectra are analyzed to identify chemical elements. The spatial resolution of LIBS is limited by the wavelength and beam quality of the laser used for ablation. The experiments may be conducted in vacuum, controlled atmosphere, or ambient air.
The Effect of Thin Water Films on Force Microscopy Measurements
Authors: Sedin D , Rowlen K 
Published: July 2020

Abstract
The atomic force microscope (AFM) is a powerful tool for probing surface topography, in addition to chemical and mechanical properties of surfaces. To investigate the chemical properties of a sample, force measurements are made between the AFM's “molecular finger,” or probe, and the sample. Force measurements can be made in many environmental conditions, which makes the AFM a versatile technique. However, in ambient conditions most samples are covered by a thin layer of water. When the AFM probe comes into contact with the thin water layer, a capillary bridge forms between the AFM probe and sample. Because of this water layer, it is believed that in ambient conditions a non-surface specific capillary force dominates the adhesive force between the AFM probe and sample. The non-surface specific capillary force should obscure any information about the surface. Currently, we are studying to what extent the capillary forces are non-surface specific and what influence this has on pull-off-force measurements.
Effect of surface oxide characteristics on Scanning Capacitance Microscopy Imaging
Authors: Konkar Atul A , Chen Wei , Noehring Kari 
Published: July 2020

Abstract
Scanning capacitance microscopy (SCM) is currently one of the most promising tools for twodimensional carrier profiling. This technique, based upon atomic force microscope (AFM) operated in the contact mode, uses a conductive probe which is scanned over the semiconductor surface. The conductive probe, oxide on the surface of the semiconductor, and the semiconductor substrate form a metal-oxide-semiconductor (MOS) structure. An a.c. bias is applied to the tip and the capacitance of the MOS structure is monitored. The a.c. bias changes the depletion of carriers in the semiconductor and thus the total capacitance of the structure. The maximum capacitance of the MOS structure is obtained when the semiconductor is in accumulation and the total capacitance of the structure is the capacitance of the semiconductor surface oxide. The minimum capacitance is obtained when the semiconductor region under the tip is in inversion. Since SCM the output signal is proportional to the differential capacitance, to get a high signal we need to maximize the difference between the maximum and minimum in the total MOS capacitance.