bluuebunny/crossref_metadata_2025_split huggingface dataset:
Densification of Monosdisperse Iron Nanoparticles from a Colloidal Dispersion at Moderate Heating Rates and Temperatures
Authors: Crane Nathan B , Sachs Emanuel , Allen Samuel M 
Published: April 2011

AbstractThis work reports on the densification of iron nanoparticles heated at moderate rates without applied pressure as observed by TEM imaging, gas adsorption pore size measurement, and X-ray diffraction. Despite a low packing density, the small pore size is amenable to significant densification by pressureless sintering. Carbon residues from the stabilizing ligands affect both the composition and processing of the particles. This approach is amenable to deposition on non-planar or fragile substrates. Additionally, large areas can be processed in parallel.
Experimental Observations of Cylindrical Indentation of a Metallic Glass
Authors: Bastawros Ashraf , Biner S.B. , Bastawros Ashraf 
Published: April 2011

AbstractIn this study, the deformation behavior of a metallic glass under a cylindrical indenter is elucidated with in situ observations. The experimental observations for various indenter radii provide information on both macroscopic and microscopic details of the deformation. The deformation zones developed under indenters with different radii were found to be self-similar, in agreement with the predictions of the cavity expansion model. It will be shown that, the evolution of shear bands under the indenter resembles the solutions obtained from the slip line analysis. Finally, full field strain measurements can provide the detailed information regarding the temporal and the spatial evolution of the shear bands during the course of deformation.
Effects of Glass-Forming Metallic Film on the Fatigue Behavior of C-2000 Ni-Based Alloy
Authors: Liu F. X. , Chiang C. L. , Chu J. P. , Gao Y. F. , Liaw P. K. 
Published: April 2011

AbstractGlass-forming Zr47Cu31Al13Ni9 (in atomic percent) films of various thicknesses were deposited on the C-2000 Ni-based alloy substrate by magnetron sputtering. Four-point-bending fatigue tests were conducted on the above system with the coated surface on the tensile side. It has been found that both fatigue life and fatigue-endurance limit can be considerably improved, while the degree of fatigue resistance enhancement depends on the maximum applied stress and the film thickness. Mechanisms of fatigue-resistance enhancements of the coated Ni-based alloy are discussed from the following aspects: reduction of surface roughness by the thin-film coating, good adhesion between thin film and substrate, development of residual compressive stress, and excellent ductility of glass-forming thin film (which would be otherwise brittle in bulk form). Of particular interest, we examine the interaction of substrate slip bands and the thin film ductile property, which would delay fatigue crack initiation process and thus extend the fatigue life.
Accelerated sintering of SiC Nanopowder with Stacking Disorder-Order Transformation
Authors: Shirai Kenshiro , Yamamoto Takeshi A , Ohyanagi Manshi , Munir Zuhair A 
Published: April 2011

AbstractConsolidation of SiC nanopowder with stacking disordered structure was accelerated by milling with the AlN as the additive. SiC powders without the additive was sintered at 1900°C to a density of 99%. The grain size of the sintered material was approximately 500 nm. On the other hand, with AlN as additive, the sintering temperature to reach a density of 98% was reduced to 1700°C by the addition of 1.0 mol% AlN. The grain size of this material was less than 100 nm. The effect of AlN addition on SiC sintering with disorder-order transformation was evaluated by shrinkage profile, XRD analysis, and TEM observation.
High-Strain-Rate Dynamic Mechanical Properties of a W-Reinforced Zr-Based Bulk Metallic Glass Composite
Authors: Martin Morgana , Thadhani Naresh N. , Kecskes Laszlo J. , Dowding Robert J. 
Published: April 2011

AbstractThe structural/mechanical behavior of zirconium-based (Vitreloy106) bulk metallic glass reinforced with tungsten particles is evaluated using elastic and plastic property measurements via static and dynamic compression tests performed on rod shaped samples. Anvil-on-rod impact tests combined with high-speed digital photography and velocity interferometry are used to obtain qualitative and quantitative information about the transient deformation and failure response of the composites. The deformation and failure mechanisms of recovered impacted specimens are also characterized and correlated with their structure and tungsten phase distribution. The results of these experiments and initial attempts at validating constitutive equations based on homogeneous/inhomogeneous plastic/viscous flow in glassy and glassy-crystalline composites will be presented.
Insight into the Deformation Mechanisms under a Sharp Contact Loading in Glass by Atomic Force Microscopy
Authors: Rouxel Tanguy , Yoshida Satoshi , Shang Haixia , Sangleboeuf Jean-Christophe 
Published: April 2011

AbstractThe response of a material to a sharp contact loading, as in the case of Vickers indentation for instance, provides a unique insight into the material constitutive law, including elastic and irreversible deformation parameters as well. However, under such peculiar thermodynamical and mechanical conditions (the mean contact pressure on the contact area reaches values typically higher than 1 GPa, corresponding to the hardness of the material) the deformation processes are complex and the matter located just beneath and around the contact area may experience some structural changes and behave in a way different to the expected - or known - macroscopic behaviour. It is showed in this study by means of detailed topological investigations of the residual indentations by Atomic Force Microscopy (AFM) that the elastic recovery typically represents 50 to 70 % of the indentation volume at maximum load and that the densification contribution may reach 90 % of the residual deformation volume. Besides, most glasses exhibit indentation-creep phenomena, which become significant over time scale of few minutes because of a pronounced shear-thinning behavior..
The Fabrication and Characterization of Amorphous Indium Zinc Oxide (In2O3:10wt%ZnO) based Thin Film Transistors
Authors: Yaglioglu Burag , Yeom Hyo-Young , Beresford Roderic , Paine David 
Published: April 2011

AbstractThin film transistors were fabricated using amorphous IZO (In2O3-10wt%ZnO) with low carrier concentration (∼3×1017/cm3) for the channel material and a-IZO with high carrier concentration (∼2×1020/cm3) for source-drain metallization. The performance of a-IZO channel materials processed entirely at room temperature was established using a simple gate-down thin film transistor device. The TFT test structures were fabricated on p-type Si substrates with a thermally grown SiO2 gate oxide. The channel and metallization layers were sputter deposited from a commercially available IZO target at room temperature in a gas atmosphere containing 10 vol.% and 0 vol.% oxygen, respectively. The TFT devices are depletion mode n-channel devices with a high saturation mobility (∼20cm2/Vs) and high on/off ratio (∼108) and, as such, appear to be well suited for active matrix TFT applications.
Micro-patterned NiFeMo Magnetoimpedance Multilayer for Magnetic Sensor Application
Authors: Lee Duhyun , Jeong G.H. , Kim J.H. , Kim Y.S. , Suh S.J. 
Published: April 2011

AbstractAs an alternative to the magnetoimpedance (MI) devices made from amorphous ribbon or wire, this study proposed a thin film type MI device composed with Ag conductive core and soft ferromagnetic NiFeMo sandwich layers. Obtained optimum sandwich structure was Ta 5 nm/ NiFeMo 300 nm/ Ta 5 nm/ Ag 900 nm/ Ta 5 nm/ NiFeMo 300 nm/ Ta 5 nm, and the width of Ag as 20 µm and the width of NiFeMo as 100 µm. It was patterned by using photolithography and lift-off process. The sandwich structure showed the maximum MI ratio about 40% at the 15 MHz. The impedance change was linear and nearly reversible at the external magnetic field region below the anisotropy field.
On the Mechanism of Resistive Switching in MIM Capacitors – An Approach with In-situ TEM Experiments
Authors: Schroeder Herbert 
Published: April 2011

AbstractIn this contribution an in-situ TEM experiment is suggested to observe the microstructure of a metal/oxide insulator/metal (MIM) capacitor structure during resistive switching due to an applied external voltage or current. The motivation for such an experiment is the fact that there is a large pool on the resistive switching data in the literature, but there is no agreement on the mechanism, which in part is due to missing microstructural observations of the effects. For such an experiment a special TEM sample holder has been developed allowing controlled in-situ application of temperature (RT to 300°C) with a heating stage and of voltage (current) as a part of a 4-terminal resistance measurement set-up. This is combined with a special TEM sample preparation method, the “window”-technique, so that no thinning of the MIM thin film structure is necessary at all (which is an advantage as the oxides are known to be very sensitive to damage introduced by methods such as ion-milling). Special electrode configurations have been designed to allow nearly undisturbed TEM observation of the switching insulator. Identical samples will also be investigated ex-situ in conventional switching experiments to identify the influence of the special TEM environment (high vacuum, irradiation with energetic electrons).
Nucleation and Growth of Defects in He irradiated Fe using Rate Theory and Kinetic Monte Carlo Methods
Authors: Ortiz Christophe Juan , Caturla Maria Jose , Fu Chu Chun , Willaime Francois 
Published: April 2011

AbstractHe desorption in Fe was studied using rate theory and kinetic Monte Carlo models. A good fit to experimental observations was obtained with a migration energy of 1.1 eV and a formation energy of 1.6 eV for the single vacancy. These results could be explained by the presence of traps/impurities in experiments. Simulations show that the release of He during annealing is mainly due to the dissociative mechanism (Frank-Turnbull) and the release of Hei from He-V clusters.
Ion-Induced Surface Modification of EUV and VUV Plasma-Facing Collector Mirrors
Authors: Allain Jean Paul , Hassanein Ahmed , Nieto Martin , Titov Vladimir , Plotkin Perry , Hinson Edward , Rokusek Daniel , Chrobak Christopher , Hendricks Matthew , Klimowych William 
Published: April 2011

AbstractGeneration of extreme ultraviolet (EUV) light for nanolithography requires the use of hot, dense plasmas. Gas discharge produced plasma (GDPP) and laser produced plasma (LPP) are the primary configurations used to generate these plasmas. Both GDPP and LPP collector mirror systems face serious issues regarding lifetime and EUV light reflectivity performance. For both configurations debris, fast ions, fast neutrals, and condensable EUV radiator fuels (Li, Sn) interact with nearby collector mirrors. Sn, in particular is used due to its high conversion efficiency in the 13.5-nm in-band spectrum. In addition to debris, collector mirrors are exposed to impurities (H,C,O,N), off-band radiation (depositing heat) and highly-charged ions leading to their degradation and consequently limiting 13.5 nm light reflection intensity.This work presents results of Ru and Rh-based collector optics irradiated by Sn ions between at 1.3 keV and exposed to Sn thermal atoms at room temperature. In-situ metrology monitors the effects of ion implantation on ion-induced erosion and EUV reflectivity changes using low-energy ion scattering spectroscopy and X-ray photoelectron spectroscopy. Results find that Sn implants at the first few monolayers leading to a mixed layer at the surface. Sn thermal atoms deposit on top of the mirror surface leading to 10-20% loss of collector mirror EUV light reflectivity.
A short review and Present Status of ZnO Nanoparticle Formation by Ion Implantation Combined with Thermal Oxidation
Authors: Amekura Hiroshi , Plaksin Oleg A , Umeda Naoki , Takeda Yoshihiko , Kishimoto Naoki , Buchal Christoph 
Published: April 2011

AbstractRecently many groups have started studies of formation of zinc-oxide (ZnO) nanoparticle (NP) in transparent insulators, such as silica glass, sapphire, etc, using ion implantation techniques. In the early half of this article, we shortly review recent activities of ZnO NP formation using ion implantation combined with thermal oxidation. Some groups succeeded but the others did not. Even if they succeeded in the formation of ZnO nanostructures, one reported that they were in the shape of thin film and another reported the NP form. Based on our recent experimental results, we point out the importance of the oxidation temperature and the peculiar shapes and depth profiles of ZnO formed.
Investigation of effects of ion beam irradiation on properties of magnesium oxide films
Authors: Morimoto Yasuhiko , Tanaka Yoshikazu , Ide-Ektessabi Ari 
Published: April 2011

AbstractMagnesium oxide (MgO) film is commonly used as protecting layer for alternative current plasma display panels (AC-PDPs). Low energy ion induced secondary electron emission coefficient (γ) is one of the important factors to improve performance of AC-PDPs. The aim of this study is to prepare MgO films with high γ using ion beam assisted deposition (IBAD). The film composition, density, and crystal orientation were also investigated. The results suggest that MgO films with high γ can be obtained using IBAD. On the other hand, as the assisted ion beam energy increased to more than 500eV during deposition, (200)-oriented film with low γ grew preferentially and then the γ decreased.
Teaching What You Can’t See: Museum Exhibits as a Bridge to Learning Materials Science
Authors: Castellini Olivia , Holladay Carie E. , Theim Terra , Walejko Gina K. , Zenner Greta M. , Krajniak Paul , Crone Wendy C. 
Published: April 2011

AbstractThe use of exhibits in informal science education venues such as science centers and museums is an integral part of engaging students in science, encouraging them to take science courses in school, and motivating them to pursue science and engineering careers. Through an Internships in Public Science Education Program funded by the National Science Foundation and in partnership with the education efforts of the Materials Research Science and Engineering Center (MRSEC) and the Discovery World Museum of Science, Economics and Technology, we have built and tested interactive components for museum exhibits on advanced materials science and nanotechnology concepts. Our front-end assessment revealed a gap in scientific understanding about objects smaller than can be seen by the naked eye. Facts learned through standard teaching methods were easily recalled, but in-depth, conceptual knowledge and application of those facts are lacking in both children and adults. We designed interactive exhibits to specifically address this disconnect in comprehension. By inviting the learner to actively participate in an interactive exhibit activity, he or she is able to develop a deeper understanding of advanced materials concepts that are difficult to teach with textbooks alone. Formative assessment of our exhibit prototypes show that students and adults not only participate in the interactive exhibit activity, but are able to learn and apply the concepts contained within them.
Materials Engineering Education in Two New Engineering Degree Programs at the Centre for Photovoltaic Engineering
Authors: Corkish Richard Paul , Wenham S. R. , Cotter J. , Sproul A. B. , Aberle A. G. , Bruce A. , Green M. A. 
Published: April 2011

AbstractThe establishment, in 2000 and 2003, of new degree programs in Photovoltaics and Solar Energy Engineering and Renewable Energy Engineering at the Centre for Photovoltaic Engineering at the University of New South Wales, Sydney was in response to predictions, now being fulfilled, of dramatic global market and employment growth. They were developed by the well established photovoltaics research group at UNSW that has produced many important advances, including two commercially important solar cell technologies. Materials-related education in these programs are mainly focussed on the photovoltaic aspects, including study of the fundamental optical, electronic, phononic and excitonic properties of silicon, crystal structure, semiconductor properties, doping and contacts. Cell manufacturing is taught in detail, including by the use of an interactivevirtual production line. Practical projects, taking advantage of a large and active research group, are one of the most important and effective educational tools in both these programs. The Centre also administers postgraduate coursework and research programs.
Crystal Structure Visualizations in Three Dimensions with Database Support
Authors: Moeck Peter , Čertík O. , Upreti G. , Garrick W. , Fraundorf P. 
Published: April 2011

AbstractCrystallographic databases for inorganic materials that are freely accessible over the internet are reviewed. The Nano-Crystallography Database project is described. Instructions are given on how to visualize in three dimensions the atomic arrangements of the several thousand entries of the Crystallography Open Database.
Women in Materials: a Collaborative Effort between Simmons College and the Cornell Center for Materials Research
Authors: Goldberg Velda , Malliaras George G. , Schember Helene , Kaplan Michael , Soltzberg Leonard , Gurney Richard W. , Johnson Patrick 
Published: April 2011

AbstractThe Women in Materials (WIM) program, supported by the National Science Foundation, is a collaboration between Simmons College, a predominately undergraduate women’s college, and the Cornell Center for Materials Research (CCMR). For the past four years, this program has provided unusual curricular and research opportunities for undergraduate women at Simmons College. This program demonstrates a successful model for enhancing undergraduate science and technology preparation through collaboration between primarily undergraduate institutions (PUIs) and NSF-supported Materials Research Science and Engineering Centers.
Non-Traditional Assessments for New Learning Approaches: Competency Evaluation in Project-Based Introductory Materials Science
Authors: Stolk Jonathan , Krumholz Steven , Somerville Mark 
Published: April 2011

AbstractOver the last twenty years, NSF and the engineering community have called for systemic changes in engineering education, including an emphasis on contextual understanding; increased teaming skills, including collaborative, active learning; and an improved capacity for life-long, self-directed learning. In addition, ABET has called for engineering graduates that demonstrate an ability to apply science and engineering, and ABET requires assessment processes designed to measure student achievement of learning outcomes. Olin College has responded to these calls for change by embracing new learning approaches and assessment techniques, and by developing project-based courses that encourage experiential understanding of content and aid the development of life-long learning skills. To address the assessment needs of new pedagogical approaches, Olin recently instituted a competency based assessment system to accompany the traditional course grading system already in place. The thread of competency assessments provides grading coherency for both faculty and students, and it provides students with valuable information concerning their development of nontraditional skills that they could use to identify shortcomings and further their learning. In this paper, we describe the new pedagogical approaches in Olin's introductory materials science course, and we explain our implementation of the competency assessment system to measure student attainment of both materials science knowledge and broader skills such as teaming, communication, and experimental inquiry.
The Effect of Oxygen Contamination on the Electronic Properties of Hot-Wire CVD Amorphous Silicon Germanium Alloys
Authors: Datta Shouvik , Cohen J. David , Golledge Steve L. , Xu Yueqin , Mahan A. H. , Doyle James R. , Branz Howard M. 
Published: April 2011

AbstractA series of four a Si,Ge:H alloy samples with Ge fractions near 30 at.% were deposited by hot-wire CVD (HWCVD) using a Ta filament maintained at 1800oC. During film growth, the level of oxygen contamination was varied from less than 1019 cm−3 to roughly 5 × 1020 cm−3 using a controlled air-leak. The electronic properties of these films were then characterized using transient photocapacitance (TPC) and transient photocurrent (TPI) spectroscopy, as well as the drive-level capacitance profiling (DLCP) techniques. We observed an unexpected systematic improvement of the electronic properties of these HWCVD a Si,Ge:H with increasing oxygen impurity level, which was reflected by a decrease in the deduced Urbach energies. Comparing these with films co-deposited on stainless-steel versus p+ c-Si substrates, we found significantly better electronic properties in the latter case. Comparisons of the TPC and TPI spectra indicated a very high level of hole collection, consistent with these narrow bandtail distributions.
Phononic Amorphous Silicon: Theory, Material, and Devices
Authors: Chawda Samrat , Mawyin Jose , Mahan Harv , Fortmann Charles , Halada Gary 
Published: April 2011

AbstractThe field of phononic-engineered amorphous silicon is introduced. Specifically the construction of devices and waveguides for information conveyance and manipulation via phonons are considered. Typically the phononic properties of a given material are immutable and the phonons have such a limited diffusion length (nanometers) as to be unsuitable for engineering purposes. Crystalline silicon on the other hand has a reasonably large thermal conductivity and phonon diffusion length at sufficiently low temperatures. Phonon diffusion lengths can measure up to centimeters (e.g., crystalline SiO2) at temperature less than 10K but drop to sub microns at room temperature. Amorphous silicon, owing to the inherent scattering structures and owing to localization (of at least some phonon bands), has an anomalously large phonon lifetime [1]. This lifetime maybe indicative of a large phonon diffusion length and/or a fast phonon hop rate from one domain to the next and/or an indication that more than the typical three phonons (umklapp process) are involved in phonon scattering (e.g., see [1]&[2]). Techniques involving small-scaled devices and phonon bands to control umklapp phonon-phonon scattering are described. The potential to exploit inherent amorphous silicon structure as well as the engineering (post film deposition) of di-hydride distributions to induce phonon forbidden bands for significantly reduced multi-phonon scattering is explored. The indirect optical band gap of small domain (and possibly amorphous) silicon [3] provides the physical basis for the transduction of phonon and optical energies. Experimental methods for the post-deposition introduction of phonon scattering structure, the transduction of phononic information to optical information, and experimental approaches including the use of micro-Raman to probe phonon spectra and transport are described. The prospects of a fully integrated phononic, photonic, electronic amorphous silicon technology have been described.