bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reliable and Cost-Effective Dispensing Technology for Large-Area Patterning
Authors: Li Bo , Clark Patrick A. , Church Kenneth H. 
Published: April 2011

AbstractIt is reported that the global market for flexible electronics will reach 250 billion dollars by 2025, driven by the products on a human scale (the so called “electronics for life”). These devices such as LCDs cannot be made smaller. However, this field is immature and significant research and development is being conducted for the synthesis, manufacture and characterization of these kinds of devices. The manufacturing process has been identified as the bottleneck of the advancement of these products. High throughput, reliable and yet cost effective technologies are greatly needed for the developing of affordable and functional devices. Researchers and engineers at nScrypt have developed enabling tools and processing solutions for patterning components on large areas with great accuracy and repeatability. In this paper, we will present innovative printing/dispensing solutions as well as novel pumping technologies (smart pump) for the manufacturing and packaging on large areas. In addition to the smart pump, we have a mixer head and spray attachment for the developing of new materials and covering large area.
Theoretical Limits on the Minimal Switching Field and the Switching Current in Magnetization Reversal
Authors: Wang Xiangrong , Sun Zhouzhou 
Published: April 2011

AbstractRecent theoretical limits of the minimal switching field and current for uniaxial magnetic nano-structures are reviewed. The results include also the optimal field and current pulses for the fastest magnetization reversal. Contrary to the general belief, the precessional magnetization reversal is not the fastest one, and its critical switching field is neither the lowest one.
Atomic-Scale Segregation and Fluctuations in Chemical Ordering FePt Thin Films
Authors: Torres Karen L , Srivastava Chandan , Martens Richard L , Thompson Gregory B 
Published: April 2011

AbstractA series of atom probe and transmission electron microscopy (TEM) studies have been performed to quantify minute compositional fluctuations in Fe55Pt45 thin films during the A1 to L10 phase transformation. The atom probe specimens were analyzed in an Imago Local Electrode Atom Probe (LEAP®) at a target evaporation of 0.5%, a pulse fraction of 20% and a temperature of 120K. We noted a propensity of fracture failures in the LEAP with this material at lower temperatures. The atom probe reconstruction showed small levels of Pt segregation at grain boundaries in the as-deposited films. Fresnel-contrast TEM imaging confirmed high density fluctuations in these boundaries. Upon annealing at 600°C for 10 minutes, the film transformed from A1 to L10 and the grain boundaries become Fe enriched as compared to the as-deposited film.
Liquid-phase Epitaxial Growth of BiFeO3 Thick Films using an Infrared Irradiation
Authors: Kawae Takeshi , Shiomoto Mitsuhiro , Tsuda Hisashi , Yamada Satoru , Nagao Masanori , Morimoto Akiharu , Kumeda Minoru 
Published: April 2011

AbstractEpitaxial BiFeO3 (BFO) thick films were fabricated on SrTiO3 (STO) substrates by a simple liquid-phase epitaxy (LPE) growth technique. To avoid the evaporation of Bi, in this process, we used the lid substrate. As starting materials, we used calcined powder or amorphous films deposited by pulsed laser ablation. The fabricated films were found to have a single perovskite phase and be (100)-oriented. Cube-on-cube epitaxial growth of film on the STO substrate was also confirmed by ϕ-scan measurements. The films grown on the substrate display a multigrain structure with a maximum in-plane size of approximately 100μm, and the film thickness was about 3-35 μm. The interface structure between the film and the substrate was relatively smooth. These results indicate that the proposed simple LPE technique is highly suitable for the fabrication of BFO thick films.
Properties of Zinc Oxide Doped Indium, Magnesium and Aluminum Oxide Films used on Flexible Substrates
Authors: Hsiao Shih Hsiu , Tanaka Yoshikazu , Ide-Ektessabi Ari 
Published: April 2011

AbstractZinc oxide was considered to be substitute for indium tin oxide (ITO) as the transparent conductive oxide (TCO) films used in display industry according to indium is a rare and expensive metal. For the flexible display, the polymeric materials used as the flexible substrates are more bendable and lighter weight compared to the glass substrates used in flat panel display. However, the thermal sensitivity of polymer affects the properties of TCOs layers when it was deposited at room temperature. In this study, we doped the different ratio of indium oxide, magnesium oxide and aluminum oxide into zinc oxide to improve the properties of zinc oxide used as the TCOs films deposited by the sputtering method. The polyethylene terephthalate (PET) was used as the flexible substrate without thermal process and the glass was used as the comparison substrate with annealing. The light transmittance and the surface resistivity were measured. The chemical composition and the crystal structure were analyzed by using Rutherford backscattering spectrometry and X-ray diffraction measurement.
Tunneling Spectroscopy of Magnetic Impurities (=Mn,Fe,Co) in ZnO
Authors: Tamura Takashi , Kim Changman , Oikawa Yasushi , Ozaki Hajime 
Published: April 2011

AbstractThe first observations have been made on the electronic density of states of Mn, Co and Fe-doped ZnO by tunneling spectroscopy. For Mn- and Co-doped ZnO, rising of DOS were observed around 2.8eV and 3.2eV below the bottom of the conduction band, respectively. In these cases, the Fermi level lay at the bottom of the conduction band. For Fe-doped ZnO, the DOS with about 1.2eV width was observed around the Fermi level in the mid-gap. The result reproduced the recent theoretical calculation.
Low Temperature Silicon Nitride Films Deposited on 3D Topography by Hot Wire Chemical Vapor Deposition (HWCVD)
Authors: Warnat Stephan , Hoefer Markus , Schaefer Lothar , Foell Helmut , Lange Peter 
Published: April 2011

AbstractSilicon nitride films were deposited by hot-wire chemical vapor deposition processes (HW-CVD). The films reveal a morphological structure very similar to nitrides formed in low pressure CVD (LP-CVD) or plasma enhanced CVD (PE-CVD) processes. The electrical breakdown voltages, however, are much smaller for HW- than PE- or LPCVD films. The deposition in holes for isolation purpose in “through silicon vias” (TSV) technologies in combination with optical devices, which require very low temperatures (<200 °C), have been investigated. They reveal sufficiently good properties for the planned applications.
Direct production of the Ti-Zr-Ni-Cu icosahedral phase for hydrogen-storage applications by rapid quenching from the melt
Authors: Kocjan Andraz , McGuiness Paul J. , Recnik Aleksander , Kobe Spomenka 
Published: April 2011

AbstractOur study focused on the formation of Ti40Zr40Ni20 and Ti45Zr35Ni17Cu3 icosahedral (i-phase) quasicrystals directly from the melt and their subsequent characterization and high-pressure hydrogenation. The samples were produced in an inert-gas melt-spinning device from a series of arc-melted precursors. By varying the wheel speeds we were able to produce a range of crystallographic structures, from amorphous, through quasicrystalline, to crystalline. The ribbon thickness showed the expected reduction with wheel speed, from 120 microns to 30 microns, while the Ms exhibited a surprisingly modest change with wheel speed. The XRD analysis showed that depending on the cooling rate it was possible to freeze the icosahedral phase directly from the melt, without any subsequent heat-treatment. Using the same procedure to test the range of formation wheel speeds for a comparable system we also produced samples containing up to 3 atomic % copper. Using transmission electron microscopy we have confirmed that the ribbons contain nanosized particles of Ti40Zr40Ni20 icosahedral phase imbedded in an amorphous matrix with the same composition. The average particle size of the i-phase was approximately 20 nm. The 5-fold symmetry was confirmed by selected-area electron diffraction and high-resolution TEM having the crystallite oriented close to the symmetry axis. Both our X-ray diffraction measurements and the TEM observations have provided direct evidence for the quasicrystalline ordering of Ti40Zr40Ni20 by rapid quenching from the melt. To test the hydrogen-absorption properties of the icosahedral phase we crushed ribbons into finer particles to provide fresh, new surfaces to aid hydrogen dissociation at the metal surface. The uptake of hydrogen was found to be critically dependent on the surface state of the Ni–Ti–Zr ribbons; even modest exposure to the atmosphere produced a protective layer of oxide on the surface that practically prevented any hydrogen being taken up by the icosahedral phase. The concentration of hydrogen in the i-phase was determined from the shift in the XRD peaks. The calculated expansion of aq was 6% and the corresponding [H]/[M] value was 1.5.
Investigation of Hydrogen Storage Using Combinatorial Thin Films and IR Imaging
Authors: Oguchi Hiroyuki , Takeuchi Ichiro , Josell Daniel , Heilweil Edwin J , Bendersky Leonid A 
Published: April 2011

AbstractThree 100 nm-thick Mgx(TM)1-x (TM = Ni and Ti) composition spread thin films having compositional variation 0.4<x<0.95 and capped with a 5 nm-thick Pd layer were deposited in combinatorial electron-beam (e-beam) deposition chamber. Crystallinity of the films was characterized by scanning x-ray diffraction (XRD) and cross-sectional transmission electron microscopy (TEM). Hydrogen absorption and desorption of the films were monitored with an infrared (IR) camera that could image a full area of the films. The observed changes in IR intensity due to hydrogen absorption/desorption demonstrated sensitivity of the method to the differences in compostion, microstructure and type of TM.
The Effect of Initial Activation on Microstructures of Mg/Cu Super-laminates and Hydrogen Absorption Properties
Authors: Tanaka Koji , Takeichi Nobuhiko , Tanaka Hideaki , Kuriyama Nobuhiro , Ueda Tamotsu T , Tsukahara Makoto , Miyamura Hiroshi , Kikuchi Shiomi 
Published: April 2011

AbstractMicrostructures and hydrogen storage properties of Mg/Cu super-laminates were compared to clarify the effect of initial activation. The initial activation change micro/nano-structures of Mg/Cu super-laminates into Mg2Cu with layered structure in fine grain size of about 1μm and pores highly dispersed between layers in sub-micrometer size. Large surface area, dense defects and short diffusion distance for the reaction enable Mg/Cu super-laminates to absorb hydrogen very quickly.
Mechanical response of a single and released InP membrane
Authors: Le Bourhis Eric , Patriarche Gilles 
Published: April 2011

AbstractInP membranes have been microfabricated and released on top of an InP substrate. The release process comprises membrane photolithography, interlayer sacrificial etching of a InP/InGaAs/InP substructure and drying with CO2 at critical point. The mechanical response of the obtained small (40 µm) and thin (0.4 µm) membranes could be tested by nanoindentation. While keeping their epitaxial orientation through the fabrication process, delamination of the membrane was observed to occur before the indenting load reached 10 mN. Then cracking of the membrane was detected as a pop-in on the loading curves for loads larger than 10 mN.
Mapping of the Initial Volume at the Onset of Plasticity in Nanoindentation
Authors: Zhu Tingting , P'ng K.M.Y. , Hopkinson M. , Bushby A.J. , Dunstan D.J. 
Published: April 2011

AbstractUnderstanding the finite volume throughout which plastic deformation begins is necessary to understand the mechanics of small-scale deformation. In indentation using spherical indenters, conventional yield criteria predict that yield starts at a point on the axis and at a depth of half the contact radius. However, Jayaweera et al (Proc. Roy. Soc. 2003)[4] concluded that yield occurs over a finite volume at least 100 nm thick. Semiconductor superlattice structures, in which the stress and thickness of individual layers can be varied and in which known internal stresses can be incorporated, open up new possibilities for investigation that cannot be achieved by varying external stresses on a homogenous specimen. We have designed samples with bands of highly strained InGaAs superlattice, which are essentially bands of low yield-stress material devoid of other metallurgical artifacts. These bands are placed at different depths in a series of samples. Spherical indenters with a range of radii were used to determine the elastic-plastic transition. The stress field from different sized indenters interacts with the low yield-stress material at different depths below the surface to map out the size of the initial yield volume.
New Experimental Approach for Measuring Electrical Contact Resistance with an Accurate Mechanical Actuation, Evaluation of the Performances of Gold Micro-switches
Authors: Seguineau Cedric , Broue Adrien , Pennec Fabienne , Dhennin Jérémie , Desmarres Jean-Michel , Pothier Arnaud , Lafontan Xavier , Ignat Michel 
Published: April 2011

AbstractA specific experimental setup combining nanoindentation and electrical inputs has been developed in order to determine the reliability and the performances of Micro-ElectroMechanical Systems (MEMS) which include thin free-standing elements like micro-switches applications. The evolution of the electrical resistance with respect to a mechanical solicitation applied on the contact, are henceforth available. The description of the set-up goes with a brief overview of the tests performed on a gold ohmic switch. A discussion is developed considering the mechanisms involved in the contact response. This is based on a confrontation among the experimental results, the analytical modeling and also finite-element analysis.
Analysis and Measurement of Forces in an Electrowetting-Driven Oscillator
Authors: Crane Nathan Brad , Volinsky Alex A , Ramadoss Vivek , Nellis Michael , Mishra Pradeep , Pang Xiaolu 
Published: April 2011

AbstractElectrowetting is a promising method for manipulating small volumes of liquid on a solid surface. This complex phenomenon couples electrical and fluid properties and offers many potential surprises. The complex electrical and capillary interactions in electrowetting are illustrated by an analysis of an electrowetting configuration that produces an oscillating droplet motion from a steady DC voltage input. The paper presents an analysis of the electrowetting forces to explain the oscillation and presents a new method for measuring electrowetting forces using a Hysitron Triboindenter. Initial results are compared with predictions from numerical models and simplified analytical solutions.
Perovskite and Composite Materials for Intermediate Temperatures Solid Oxide Fuel Cells
Authors: Kharlamova T. , Pavlova S. , Sadykov V. , Krieger T. , Mezentseva N. , Muzykantov V. , Alikina G. , Boronin A. , Zaikovskii V. , Ishchenko A. , Rogov V. , Uvarov N. , Frade J. , Argirusis Chr. 
Published: April 2011

ABSTRACTLa0.8Sr0.2Fe0.6Ni0.4O2.9 (LSFN) and LSFN-La9.83Si4.5Fe1.5O26 (LSiF) nanocomposite were synthesized and investigated as cathode materials for intermediate temperature (IT) solid oxide fuel cells (SOFC). Phase and structure evolution with sample sintering temperature as well as their transport properties and catalytic activity in oxygen reduction were studied.
Synergistic Physical Properties of Multiphase Nanocomposites with Carbon Nanotubes and Inorganic Particles
Authors: Sumfleth Jan , Sriyai Montira , Prado Luis , Wichmann Malte H.G. , Schulte Karl 
Published: April 2011

ABSTRACTMultiphase epoxy-nanocomposites based on multi-wall carbon nanotubes (MWCNT) and inorganic nanoparticles (TiO2) were produced. The rheological, electrical and thermo-mechanical properties were investigated in order to reveal informations about the interparticle interactions between the different types of nanoparticles. TEM-investigations reveal altered microstructures for the multiphase nanocomposites (MWCNT plus TiO2). TiO2 causes changes in the state of dispersion of MWCNT which can lead to an increase of the rheological parameters (e.g. G'). Due to changes in the formation of the percolated MWCNT network during curing, the electrical conductivity is decreased if the concentration of the non-conductive fillers exceeds a critical value. Additional synergistic effects could be found for the glass transition temperature. The presence of nanoparticles leads to a chemical inactivation of reactive groups of the matrix. Thus, the generated interphase between matrix and nanoparticles exhibits a lower curing degree which results in lower thermo-mechanical properties. For the multiphase systems the glass transition temperature is decreased less, due to an inactivation of the surface of the different types of nanoparticles by a self assembly which leads to a higher curing degree of the interphase.
Use of Sonication and Influence of Clay Type on the Enhancement in Physical Properties of Poly(methyl methacrylate) Nanocomposites
Authors: Ingram Sharon , Dennis Hugh , Hunter Ian , Liggat John J , McAdam Craig , Pethrick Richard A , Schaschke Carl , Staszczak Sylwia K , Thomson David 
Published: April 2011

ABSTRACTThe nature of the dispersion of a clay platelet in a resin composite will play an important role in the process of enhancement of the physical properties of that material. This paper describes studies of ultrasonically and mechanically mixed dispersion of various clays in methyl methacrylate (MMA) and reports the effects of organic surface modification on the rheology, suppression of settlement of filled systems, cure characteristics and final mechanical properties.
Mechanical Properties of PDMS/CNTs Nanocomposites
Authors: Wu Chung-Lin , Lin Hsueh-Chu , Huang Chien-Hsin , Yip Ming-Chuen , Fang Weileun 
Published: April 2011

ABSTRACTThis study presents the mechanical and electrical properties (including elastic modulus, yield strength and electrical resistance) of PDMS/CNTs nanocomposites. The elastic modulus and yield strength were determined from tensile tests. In addition, a high resistance meter was used to measure the electrical resistances of the PDMS/CNTs nanocomposites. The test specimens of nanocomposites were manufactured using the thermoforming method. There were two recipes used during the thermoforming process: 100 °C for 1 hour, and 150 °C for 15 minutes. The mixtures of PDMS and CNTs were stirred by ultrasonic instrument to prevent polymerization. A feeler gap was used to define the thickness of the specimens. Therefore, the thickness could be controlled within the range of ∼100 μm. Four different kinds of specimens were investigated, including pure PDMS, 1.0 wt%, 2.0 wt% and 4.0 wt% CNTs polymeric composites. As for the l00°C recipe, the elastic modulus of pure PDMS, 1.0 wt%, 2.0 wt%, and 4.0 wt% CNTs were 1.05MPa, 1.17MPa, 1.10MPa and 1.35MPa, respectively. A for the l50°C recipe, the elastic modulus of pure PDMS, 1.0 wt%, 2.0 wt% and 4.0 wt% CNTs were 1.32MPa, 1.42MPa, 1.43MPa, and 1.54MPa. The differences of electrical resistance of PDMS/CNTs nanocomposites at two different conditions and the microstructures composed of the mixtures are also described in this article.
Silicon Carbide Nanowire Heterostructures Constructed from Released Iron Catalysis
Authors: Liu Zhenyu , Srot Vesna , van Aken Peter A. , Rühle Manfred , Yang Judith C. 
Published: April 2011

ABSTRACTHerein, we present the capability of creating silicon carbide (SiC) nanowires and branched nanostructures via a released cataltic process. Core-shell structured carbon-encapsulated iron nanoparticles were used as catalysts for SiC nanostructures formations by vapor-solid reaction. Various SiC nanostructures, including SiC nanocones, biaxial SiC-SiC composite nanowires, SiC-Fe-SiC junctions, Y, T branched SiC nanowires, and other complex heterostructures were observed from this process. It was demonstrated that the encapsulated iron could gradually migrate out of the carbon shell, and the released iron nanoparticles catalyzes the SiC nanostructures formation. Their morphologies and microstructures were investigated by different techniques, including scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electron microscopy (TEM), and their formation mechanisms are proposed.
Synthesis and Characterization of High Quality InN Nanowires and Nano-networks
Authors: Cai Zhihua , Garzon Samir , Webb Richard A. , Koley Goutam 
Published: April 2011

ABSTRACTHigh quality InN nanowires have been synthesized in a horizontal quartz-tube furnace through direct reaction between metallic Indium and Ammonia using Nitrogen as the carrier gas. Thin film of Au on SiO2/Si substrate has been used as the catalyst layer, facilitating vapor-liquid-solid growth of the nanostructures. The nanowires were grown at a very fast rate of up to 30 μm/hr. Smooth and horizontal nanowire growth was achieved only with nanoscale catalyst patterns, while large area catalyst coverage resulted in uncontrolled and three-dimensional growth. The InN nanowires, which were usually covered with a thin shell layer of In2O3, grew along [110] direction, with overall diameters 20 - 60 nm and lengths 5 - 15 μm. The synthesized nanowires bent spontaneously or got deflected from other nanowires at multiples of 30 degrees forming nano-networks. The catalyst particles for the NWs were found mostly at the sides of the NW apex which helped them to bend spontaneously or get deflected from other NWs at angles which were multiples of 30 degrees. The NW based FETs with a back-gated configuration have already been investigated. The gate-bias dependent mobility of the NWs ranged from 55 cm2/Vs to 220 cm2/Vs, and their carrier concentration was ∼1018 cm−3.
Large-Scale Hierarchical Self-Assembly Structures from Gold Nanoparticles
Authors: Kim Nam-Jung , Li Hao 
Published: April 2011

ABSTRACTMetallic nanoparticles may form hierarchical dendrites in the presence of ionic surfactant through self-assembly upon solvent drying at room temperature. With nanoparticle density varying in the drying area on the supporting solid substrate, the morphology and relevant size of the dendrites evolve in different structures. At the region where the nanoparticle density is high, the large dendrite can develop with manifest crystal symmetry. At the low density region, many small sizes of compact crystals can be found, indicating that particle nucleation dominates over the long-range crystal growth. SEM image reveals the ordered stacking of gold nanoplates over the long dendrite branches, resembling the liquid crystal array. We present the possible physical origins to explain the various structures of the assembled dendrites during the solvent evaporation at the interface of solid and air.
A Cell's Perspective of its Culture Surface
Authors: Yongsunthon Ruchirej , Baker David E. , Baker Wendy A. , Chang Theresa , Walczak Wanda J. , Senaratne Wageesha , Petzold Odessa N. , Youngman Randall E. 
Published: April 2011

ABSTRACTAtomic Force Microscopy (AFM) was employed to probe the internal structure of living HepG2/C3A cells grown on various commercially-available substrates. In order to understand the driving mechanisms behind the different cell morphologies, the surface properties of these substrates was characterized with AFM and related techniques. The roughness of a 10μm×10μm region of a series of substrates was determined and found to be independent of both coating and culture media, with the exception of thick hydrogel-like coatings. Probing with functionalized tips could not distinguish relative degrees of hydrophobicity under cell culture media, presumably because Debye shielding masks the substrate surfaces. Force spectroscopy was performed on the surfaces to determine exposed surface proteins/polymers intrinsic to the substrate and adsorbed from culture media. Preliminary investigation of cell-mediated substrate reconstruction suggests that the cells secrete large (1000kDa) polymeric molecules at the substrate interface.