bluuebunny/crossref_metadata_2025_split huggingface dataset:
Displacement Current Staircase due to Coulomb Blockade
Authors: Nagano Kouhei , Okuda Atsushi , Majima Yutaka 
Published: April 2011

AbstractIn the two-junction system of the scanning vibrating probe/ Au dot / vacuum / Si structure, theoretical equations of both the displacement current waveform iD(t) and the mean displacement current ID(VP) due to Coulomb blockade are analyzed by using the orthodox theory. By usingtheoretical iD(t), the single electron motion on a Coulomb island in a period of probe vibration isexplained. Experimental ID(VP) curves due to Coulomb blockade under a constant probe voltage VP clearly show the displacement current staircase and are in good agreement with the theoretical ID(VP) curve. By using this method, the average number of quantized electrons on Au dots is directly measured through the displacement current staircase.
Investigation of Pt/Si/CeO2/Pt MOS Device Structure by Impedance Spectroscopy
Authors: Lappalainen Jyrki , Kek Darja , Tuller Harry L. 
Published: April 2011

AbstractEpitaxial growth of dielectric layers on silicon substrates has attracted a great deal of recent interest given their potential applicability in the fabrication of high quality silicon-on-insulator (SOI) structures, high density capacitor devices, and stable buffer layers between silicon and other materials. Cerium dioxide (CeO2) appears to be a particularly attractive candidate, given its high dielectric constant and its compatibility with Si. To date, measurements of the electrical properties of CeO2 films on Si have been largely limited to room temperature. In this study, thin films of CeO2 were prepared by in situ pulsed laser deposition (PLD) on n-type (100) silicon substrates, with varied deposition conditions. Capacitance-voltage measurements (C-V) were used to characterize the response of the Pt/Si/CeO2/Pt MOS capacitor structure. Impedance measurements were performed from room temperature to 350°C. This enabled the independent characterization of the electrical signature of the Pt/Si interface which was found to contribute insignificantly above approximately 150°C. The CeO2 film conductivity was found to be thermally activated with activation energy of ∼0.45 eV, with its magnitude strongly dependent on film microstructure.
FT-IR spectra of Li(AlxCo1-x)O2 (x=0.1-0.5)
Authors: Hao W. , Li C. , Meng X. , Chen G. , Xu W. 
Published: April 2011

AbstractFT-IR spectra from Li(AlxCo1-x)O2 (x=0.1-0.5) are reported. It was found out that there are four peaks located at 556cm−1, 601cm−1, 1438cm−1, 1498cm−1. First two peaks at 556cm−1 and 601cm−1 can be assigned to A2u and Eu vibration modes, respectively. The other two new peaks at 1438cm−1 and 1498cm−1 can not be explained clearly. With the increasing of Al concentration, all peaks position remain unchanged. However a relative change in the intensity of A2u and Eu peaks was observed.
Relation Between Heat-Treatment Temperature and Characteristics of Polyparaphenylene(PPP)-Based Carbon Materials for Lithium Ion Secondary Batteries
Authors: Osawa Kozo , Nakazawa Tatsuo , Oshida Kyoich , Endo Morinobu , Dresselhaus Mildred S. 
Published: April 2011

AbstractPolyparaphenylene (PPP)-based carbon powder is expected for materials of the negative electrode of the lithium ion secondary batteries. In this study, effects of heat treatment temperature on the PPP materials are investigated by means of electrical and structural measurement. The layer structure of the powder is analyzed in detail by the transmission electron microscope observation combined with digital image processing. Charge-discharge current characteristics, electrical resistivity under pressure and layer structure of the PPP-based carbon powder are measured and discussed.
Electrical Characterization of Inhomogeneous and Heterogeneous Systems with Microstuctural Periodicity
Authors: Maier Joachim 
Published: April 2011

AbstractThis paper discusses how inhomogeneities and heterogeneities enter impedance and conductivity analyses in the case of microstructural periodicity. The specific considerations of various examples of ionically and ionically/electronically conductiong materials systems (bicrystals, microcrystalline and nanocrystalline samples) show how a reliable and thorough characterization is possible.
Combinatorial Synthesis and Characterization of CoMnGe Alloys
Authors: Tsui Frank , He Liang , Ma Lei 
Published: April 2011

AbstractTernary alloys of CoMnGe have been synthesized and characterized using combinatorial molecular beam epitaxy techniques. Structural evolution was studied using real-time scanning reflection high-energy electron diffraction, and magnetic properties were probed using magnetooptic Kerr effect imaging and SQUID magnetometry. Growth and properties on several substrate orientations were explored. These alloys exhibit a rich variety of magnetic and magnetooptic behavior, including a robust phase near Co2MnGe with high spin polarization, Tc, and magnetooptic response. The observed magnetic responses show strong correlation with structural transformations, such that structural ordering leads to enhanced magnetism. The observed magnetic behavior and the alloys’ compatibility with Ge and Si substrates make them potential candidates for spin electronic transport studies and applications.
High Throughput Optimization of Y-Type Magnetoplumbite Epitaxial thin Film Growth by Combinatorial Pulsed Laser Deposition Technique
Authors: Ohkubo I. , Matsumoto Y. , Ohtani M. , Hasegawa T. , Ueno K. , Itaka K. , Parhat A. , Chikyow T. , Kawasaki M. , Koinuma H. 
Published: April 2011

AbstractThin films of Y-type magnetoplumbite (Ba2Co2Fe12O22: Co2Y) with such a huge unit cell length as 43.5 Å has been successfully fabricated for the first time with the aid of combinatorial optimization of pulsed laser deposition process. Planning a thickness gradient CoO buffer layer on MgAl2O4(111) substrate was very effective for prevent the phase separation of Co deficient impurity (BaFe2O4) to reside in the formation of desired Co2Y phase.From the TEM analysis, the CoO buffer layer of optimum thickness was incorporated into the Co2Y film to make theinterface with the make an atomically sharp.
Array Based Carbon Black-Polymer Composite Vapor Detectors for Detection of DNT in Environments Containing Complex Analyte Mixtures
Authors: Briglin Shawn M. , Freund Michael S. , Sisk Brian C. , Lewis Nathan S. 
Published: April 2011

AbstractThin films of carbon black-organic polymer composites have been deposited across two metallic leads, with sorption of vapors producing swelling-induced resistance changes of the detector films. To identify and classify vapors, arrays of such vapor sensing elements have been constructed in which each element of the array contains a different polymer as the insulating phase and a common conductor, carbon black, as the conducting phase. The differing gas-solid partition coefficients for the various polymers of the detector array produce a pattern of differential resistance changes that is used to classify vapors and vapor mixtures. The performance of this detector array system towards 2,4-dinitrotoluene, the predominant signature in the vapor phase above land mines, in the presence high concentrations of water or of acetone (as a selected volatile organic carbon vapor), has been evaluated.
Development of Robot System and X-ray Powder Diffraction for Combinatorial Materials Research
Authors: Yanase Ikuo , Fujimoto Kenjiro , Takada Kazunori , Ohtaki Takugo , Watanabe Mamoru 
Published: April 2011

AbstractWe developed a combinatorial robot system as the first step of combinatorial approach to wet and dry synthesis of ceramics. In this study, nanoparticles mixtures having maghemite and a small amount of Y2O3 were prepared successively by using the combinatorial robot system. maghemite and Y2O3 slurries were volumetrically and automatically measured and mixed by repetition of sucking and injecting with a micro-pipette attached to the robot arm. The structural phase transition temperature of maghemite to hematite, which was investigated from the exothermic peak in the DTA curve, increased from ca.813K to ca.1093K by 2atom%Y2O3 addition. It was considered that Y2O3 dissolution into the crystal structure of maghemite had an important role on increasing the temperature of the structural phase transition for stabilizing maghemite phase. (Combinatorial, Slurries, Maghemite, Nanoparticles, Phase transition)
Photochemical Nucleation of Copper on Polyimide Surface with 10ns Laser Irradiation - Growth of Copper Metal on Copper Nuclei and Deposition of SiO2 film on Copper Metal
Authors: Tokunaga H. , Ogawa Y. , Murahara M. 
Published: April 2011

AbstractCopper atoms were substituted on the polyimide surface in the presence of CuSO4 solution with only 10ns single shot of ArF laser. Then, we have succeeded in substituting copper atoms with dangling bonds of carbon cross- linking with oxygen atoms. In this study, we placed fused silica glass on the polyimide surface firstly, and poured the sulfate solution into the gap between the silica glass and the film, forming a thin liquid layer. Then, one shot of circuit patterned ArF laser light having 42mJ/cm2 was irradiated vertically onto the sample. The photon is dissociating and exciting the copper sulfate solution and the polyimide surface. The dissociated copper atoms form the C-O-Cu bond with active oxygen on the polyimide surface. However, we were able to grow a copper thin film of about 24μm after immersing the sample into the electro less plating solution for 15 minutes at 60.On the other hand, we have laminated transparent and low dielectric constant SiO2 film at room temperature on polyimide surface by using Xe2 excimer lamp. Then, the copper film deposited on polyimide film and the piece of silicon were placed in the reaction chamber with mixing NF3 and O2 gasses in the ratio of 10:1; total pressure 330 Torr. Then, Xe2 excimer lamp was irradiated for 20 minutes. By the photochemical reaction, SiF4 and NO2 were produced. The adsorbed SiF4 on copper and polyimide surface of one molecule layer and NO2 up react with NO2, and growth SiO2 film on the sample surface. A chain reaction of film formation is brought about by these two chemical reactions of adsorption and oxidization. By this film formation film thickness was not more than 600 after 20 minutes with the Xe2 excimer lamp irradiation in order to lose in SiF4. Then, the silicon was supplied, and insufficient SiF4 was filled by ablating the silicon wafer by focused ArF excimer laser beam.
The Rational Discovery FrameworkTM: A Novel Tool for Computationally Guided High-Throughput Discovery
Authors: Landrum Gregory A. , Genin Hugh 
Published: April 2011

AbstractThe Rational Discovery Framework(TM) is a novel approach for providing computational guidance in the high-throughput discovery process. The Framework uses a proprietary machine-learning algorithm to construct predictive models from existing experimental data. These predictive models are used to computationally screen the contents of large virtual libraries. A variety of experimental design techniques can be brought to bear on the results of a virtual library screen in order to suggest an optimal set of synthesis candidates for the next round of experimentation. We have demonstrated the power and generality of the Rational Discovery Framework in a series of proofs of concept. Here we present an overview of the Framework as well as the results of studies aimed at developing predictive models for materials properties: ferromagnetism in ordered and disordered transition-metal alloys; and prediction of Tc values for superconductors.
Parameterization of Transient Models of Defect Dynamics in Czochralski Silicion Crystal Growth
Authors: Sinno Talid , Frewen Thomas , Dornberger Erich , Hoelzl Robert , Hoess Christian 
Published: April 2011

AbstractA transient model for point defect dynamics during Czochralski silicon crystal growth is parameterized using detailed experimental data generated under varying crystal growth conditions. Simulated Annealing is used to perform the model parameterization because of the complex nature of the defined objective functions. It is shown that the method is robust and despite the computational expense associated with a large number of function evaluations, can be readily used in multiple dataset, multiple objective function environments.
Going Through Rough Times: from Non-Equilibrium Surface Growth to Algorithmic Scalability
Authors: Korniss G. , Novotny M.A. , Rikvold P.A. , Guclu H. , Toroczkai Z. 
Published: April 2011

ABSTRACTEfficient and faithful parallel simulation of large asynchronous systems is a challenging computational problem. It requires using the concept of local simulated times and a synchronization scheme. We study the scalability of massively parallel algorithms for discrete-event simulations which employ conservative synchronization to enforce causality. We do this by looking at the simulated time horizon as a complex evolving system, and we identify its universal characteristics. We find that the time horizon for the conservative parallel discrete-event simulation scheme exhibits Kardar-Parisi-Zhang-like kinetic roughening. This implies that the algorithm is asymptotically scalable in the sense that the average progress rate of the simulation approaches a non-zero constant. It also implies, however, that there are diverging memory requirements associated with such schemes.
Statistical Modeling of a Dislocation Phase-Field in Ductile Single Crystals
Authors: Koslowski M. , Ortiz M. , Cuitino A.M. 
Published: April 2011

ABSTRACTA model for the description of strain hardening and hysteresis at different temperatures and strain rates in ductile single crystals is introduced. The theory accounts for: and arbitrary number and arrangement of dislocation lines over a slip plane; the long-range elastic interactions between dislocation lines; the core structure of the dislocations; the interaction between the dislocations and applied resolved shear stress field; and the dissipative in teractions with short-range obstacles and lattice friction, resulting in hardening, path dependency and hysteresis. We introduce a variational formulation for the statistical mechanics of dissipative systems. The influence of finite temperature as well as the mechanics are modeled with Metropolis Monte Carlo simulations and a mean field approximation. The theory predicts a range of behaviors which are in qualitative agreement with observation, including: hardening and dislocation multiplication under monotonic loading and hysteresis loops under under cyclic loading. The flow stress was found to be dependent on the temperature and on the strain rate only at finite temperature.
An Extended Cahn-Hilliard Model for Interfaces with Cubic Anisotropy
Authors: Abinandanan T.A. , Haider F. 
Published: April 2011

ABSTRACTFor studying systems with a cubic anisotropy in interfacial energy σ, we extend the Cahn-Hilliard model by including in it a fourth rank term, which leads to an additional linear term in the evolution equation for the compositioneld. It also leads to an orientation-dependent effective fourth rank coeffcient γ(hkl) in the governing equation for the one-dimensional composition prole across a planar interface. The main effect of a non-negative γ(hkl) is to increase both σ and interfacial width w, each of which, upon suitable scaling, is related to γ(hkl) through a universal scaling function. The anisotropy in the interfacial energy can be large enough to give rise to corners in the Wul. shapes in two dimensions. In particles of finite sizes, the corners get rounded, and their shapes tend towards the Wul. shape with increasing particle size. In the study of unmixing of concentrated alloys, the anisotropy not only leads to non-spherical particle shapes, but also to strongly elongated morphologies.
Engineering Properties of Spider Silk
Authors: Ko Frank K. , Kawabata Sueo , Inoue Mari , Niwa Masako , Fossey Stephen , Song John W. 
Published: April 2011

ABSTRACTMotivated by the high level of strength and toughness of spider silk and its multifunctional nature, this paper reports on the engineering properties of individual fibers from Nephila Clavipes spider drag line under uniaxial tension, transverse compression and torsional deformation. The tensile properties were compared to the Argiope Aurentia spider silk and show different ultimate strength but similar traits of the unusual combination of strength and toughness characterized by a sigmoidal stress-strain curve. A high level of torsional stability is demonstrated. comparing favorably to other aramid fibers (including Kevlar fibers).
Composites of Carbon Filaments Made from Methane
Authors: Shui Xiaoping , Fu Xuli , Segiet Martin , Chung D.D.L. 
Published: April 2011

ABSTRACTPolymer-matrix and cement-matrix structural composites containing discontinuous carbon filaments (diameter = 0.1 μm) that were made catalytically from methane were developed for structural and electromagnetic functions. The composites were particularly attractive for electromagnetic interference shielding and radio wave reflection, due to the skin effect and the small diameter of the filaments. Coating the filaments with nickel by electroplating further enhanced the electromagnetic performance. However, the composites were not attractive for structural functions other than vibration damping, due to the large amount of interface between the filaments and the matrix. An effective configuration for the damping function involved using the filaments as an additive between the laminae of continuous conventional carbon fibers in a polymer-matrix structural composite.
Some Aspects on Preparation and Properties of Alginate and Chitosan Fibres
Authors: Struszczyk Henryk 
Published: April 2011

ABSTRACTDemand for special fibres produced from natural polymers such as alginate, chitin or chitosan, starch, keratin or biosynthesised cellulose is a function of their unique properties and growing areas of application. Two types of fibres made from chitosan and alginate are discussed in this paper. The wet-spinning method was applied for their manufacture using modified spinning solutions of the polymers. The properties and some of the application areas of chitosan and alginate fibres are discussed.
Processing and Optical Properties of YAG- and Rare-Earth-Aluminum Oxide-composition Glass Fibers
Authors: Weber Richard , Abadie Johan , Key Thomas , Hixson April , Nordine Paul , Feillens Yannick , Noguchi Hiroshi , Kurz Jonathan , Wood Brandon , Digonnet Michel , Fejer Martin 
Published: April 2011

ABSTRACTRare-earth-aluminum oxide-composition glass fibers 5-50 μm in diameter and containing up to 50 mole % rare-earth oxide were drawn from undercooled liquids 550-650 K below the equilibrium melting point. The fibers have tensile strengths of ∼6 GPa, glass transition temperatures of ∼1150 K, and infrared transmission up to ∼5500 nm. The optical properties of erbium-doped fibers containing up to 12.5 mole % Er2O3 were investigated. The 1/e lifetime of the 4I13/2 excited state was 0.8-7 ms, decreasing with increasing Er concentration. Amplified spontaneous emission measurements indicate extremely broadband spectra, up to 135 nm (3-dB width) in 0.5 mole % fibers. Although this result is encouraging, the gain bandwidth, which has not been measured, is likely narrower. Glass fibers were crystallized by heat treatment under tension at temperatures of 1300-1900 K to form flexible, creep resistant polycrystalline monofilaments with tensile strengths up to 2.4 GPa.
Bulk Microstructure and Local Elastic Properties of Laminate Composites Studied by the Microacoustical Technique
Authors: Levin Vadim M. , Liu Songping , Guo Enming 
Published: April 2011

ABSTRACTThe focused ultrasonic beam technique has been employed for imaging of bulk microstructure of fiber-reinforced composites, for measuring local elastic properties and mapping their distribution over the composite body. Ultrashort probe pulses (operation frequency of 50 MHz) provide resolution of 100 μm. The technique has been employed for nondestructive layer-by-layer imaging of microstructure of CFR laminate composites. Series of acoustic images in planes parallel to the specimen face (C-scans) or perpendicular to it (B-scans) enable to reconstruct of bulk microstructure of compound unidirectional CFR laminates. Different types microdefects, including failures in interply adhesion, buckling of single prepreg plies, internal defoliations and disbonds, have been observed. The method has been applied to measure local values of elastic wave velocities in laminates within area of 100 - 150 μm diameter.Quality of acoustic images depends on kind and density of fiber packing and on depth of position of the imaging plane. Experience shows that specimens 2-10 mm thick are appropriate for visualization of their bulk microstructure and measuring local values of sonic velocities. The technique is promising for NDE of different composites, not only for carbon-based ones.
Crystallization Mechanism of Amorphous Mullite and the Al2O3-SiO2Phase Diagram
Authors: Kriven Waltraud M. 
Published: April 2011

ABSTRACTRecent progress in the crystallization of amorphous mullite (3Al2O3•2SiO2) and yttrium aluminate (Y3Al5O12, 5Al2O3•3Y2O3or “YAG”) beads and fibers is reviewed. Studies were made by differential thermal analyses, (DTA, DSC), synchrotron X-ray diffraction and Rietveld profile fitting, HREM, EDS and SEM. Crystallization kinetics, activation energies and microstructures were determined, leading to temperature-time-transformation (T-T-T) curves. The crystallization of mullite from the solid state proceeds by formation of large-grained, pseudo-tetragonal mullite of composition 70 mol% Al2O3, which is highly strained and which contains <10 nm silica-containing inclusions. During further heat treatments, the inclusions react with the first-formed mullite yielding single phase, orthorhombic mullite of 60 mol% Al2O3. Recrystallization also occurs on further heating with a significant reduction of grain size, in a manner similar to recrystallization in brass. These observations (using more modern and sensitive characterization techniques) suggest the presence of a peritectic-like, syntectic or syntectoidal invariant reaction in the Al2O3-SiO2phase diagram. Further work needs to be done to ascertain whether the reaction is an equilibrium or non-equilibrium phenomenon.