bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of Magneto-Optical Imaging for High-Throughput Characterization of Combinatorial Magnetic Thin Films
Authors: Zhao X. R. , Okazaki N. , Konishi Y. , Akahane K. , Kuang Z. , Ishibashi T. , Sato K. , Koinuma H. , Hasegawa T. 
Published: April 2011

ABSTRACTA new magneto-optical (MO) imaging system for high-throughput characterization of combinatorial magnetic thin films has been developed. The instrument allows us to measure both Faraday rotation and ellipticity maps at various wavelengths (400 nm∼1000 nm), different magnetic fields (0∼2000 G), and different temperatures (12 K∼300 K) for wide variety of materials. We used the magnetic circular dichroism (MCD) modulation technique to map MO properties, relatively free from substrate effects. The superiority of this system is that magnetic hysteresis curves of numerous specimens with different compositions prepared by the combinatorial technique can be simultaneously measured at one sweep of magnetic field, providing an efficient characterization method for combinatorial magnetic materials. We also confirmed that the system possesses enough spatial resolution and sensitivity for detecting MO signals of individual pixels contained in a combinatorial library.
Micro X-Ray Fluorescence As A High Throughput Screening Method For Combinatorial Chemistry
Authors: Havrilla George J. , Miller Thomasin , Warner Benjamin , Wells Cyndi 
Published: April 2011

ABSTRACTMicro X-ray fluorescence is used as a high-throughput screening method for combinatorial applications. These include chemical weapon degradation products, catalytic phosphate hydrolysis and radiologic dispersion device metals. In each application the intrinsic elemental signature was utilized to identify the lead hits for the combinatorial screening in locating peptide sequences exhibiting the desired binding characteristics. In addition to being nondestructive, rapid and non-perturbing to the binding event, this method can be used to quantify the amount of target material.
Machine-Learning Models for Combinatorial Catalyst Discovery
Authors: Landrum Gregory A. , Penzotti Julie , Putta Santosh 
Published: April 2011

ABSTRACTStandard machine-learning algorithms were used to build models capable of predicting the molecular weights of polymers generated by a homogeneous catalyst. Using descriptors calculated from only the two-dimensional structures of the ligands, the average accuracy of the models on an external validation data set was approximately 70%. Because the models show no bias and perform significantly better than equivalent models built using randomized data, we conclude that they learned useful rules and did not overfit the data.
Application of Combinatorial Chemistry Methods to The Development of Organic Coatings
Authors: Chisholm Bret , Potyrailo Radislav , Cawse James , Brennan Michael , Shaffer Ron 
Published: April 2011

ABSTRACTA combinatorial method for the development of organic clear coatings for plastic substrates has been developed. The combinatorial process or combinatorial factory has a throughput on the order of 100–200 coatings per day and possesses all of the aspects of a conventional combinatorial process such as automated sample preparation, miniaturized samples configured in an array format, high throughput screening of the properties of interest, and computer software developed for data management, storage, and analysis. The combinatorial factory greatly enhanced the rate of organic clear coat development.
Combinatorial Strategies for Thin Organic Films -Polythiophene via Surface Polymerization by Ion Assisted Deposition
Authors: Hanley Luke , Tepavcevic Sanja , Choi Yongsoo 
Published: April 2011

ABSTRACTCombinatorial strategies are applied to surface polymerization by ion assisted deposition (SPIAD) for the production of polythiophene films. Thiophene ion energy in the range of 25–200 eV and ion to α-terthiophene neutral ratio are varied to tune the extent of surface polymerization and film photoluminescence. SPIAD polythiophene films are grown by both mass-selected and non-mass-selected ions, while x-ray photoelectron spectroscopy and surface mass spectrometry are applied to determine film chemistry and the extent of polymerization. This work demonstrates that ion kinetic energy and ion to neutral ratio can be varied over a wide range in SPIAD to select films with useful optical or electronic properties. The essentially combinatorial approach of SPIAD can be dramatically extended by use of new ions and/or neutral species.
Combinatorial methods and high-throughput experimentation in synthetic polymer chemistry
Authors: Hoogenboom Richard , Meier Michael A. R. , Schubert Ulrich S. 
Published: April 2011

ABSTRACTCombinatorial chemistry has revolutionized the drug discovery as well as the catalyst discovery and optimization process during the last years. Nowadays, triggered by these developments, combinatorial methods and parallel chemistry also emerge in the field of material and polymer chemistry. Especially the field of polymer research seems to be perfectly suited for these approaches since many parameters can be varied during synthesis, processing, blending, formulation and compounding. Moreover, the screening of interesting parameters, such as molecular weight, polydispersity, polymerization kinetics, viscosity, hardness or stiffness, became feasible only recently.Within this contribution we will describe our strategy to construct a most efficient workflow in the field of combinatorial polymer research. New developments made by our group as well as some general aspects will be discussed.
A Combinatorial Chemistry Study of YAG Nucleation
Authors: Hay Randall S. 
Published: April 2011

ABSTRACTA combinatorial method to screen large numbers of dopants that affect the nucleation of yttrium-aluminum garnet was developed. The method involves heat-treatment of electron-transparent sol-derived thin films on TEM grids, and counting the number and size of nuclei by TEM. Advantages and limitations of the technique are discussed. Preliminary results are presented.
The Development of Scanning Microwave Microscope for High-Throughput Characterization of Dielectric and Conducting Materials at Low Temperatures
Authors: Okazaki Sohei , Okazaki Noriaki , Sugaya Hidetaka , Zhao Xiaoru , Hasegawa Ken , Ahmet Parhat , Chikyow Toyohiro , Nishimura Jun , Fukumura Tomoteru , Kawasaki Masashi , Murakami Makoto , Mastumoto Yuji , Koinuma Hideomi , Hasegawa Tetsuya 
Published: April 2011

ABSTRACTWe developed a scanning microwave microscope (SμM) designed for characterizing local electric properties at low temperatures. A high-Q λ/4coaxial cavity was used as a sensor probe, which can detect the change of quality factor due to the tip-sample interaction with enough accuracy. From the measurements of combinatorial samples, it was demonstrated that this SμM system has enough performance for high-throughput characterization of sample conductance under variable temperature conditions.
Data Mining Approach to Ab-Initio Prediction of Crystal Structure
Authors: Morgan Dane , Ceder Gerbrand , Curtarolo Stefano 
Published: April 2011

ABSTRACTPredicting crystal structure is one of the most fundamental problems in materials science and a key early step in computational materials design. Ab initio simulation methods are a powerful tool for predicting crystal structure, but are too slow to explore the extremely large space of possible structures for new alloys. Here we describe ongoing work on a novel method (Data Mining of Quantum Calculations, or DMQC) that applies data mining techniques to existing ab initio data in order to increase the efficiency of crystal structure prediction for new alloys. We find about a factor of three speedup in ab intio prediction of crystal structures using DMQC as compared to naïve random guessing. This study represents an extension of work done by Curtarolo, et al. [1] to a larger library of data.
Unique Indexing Scheme of Decagonal Phases Based on a Six Dimensional Model
Authors: Mandal R. K. , Pramanick A. K. , Sastry G. V. S. , Lele S. 
Published: April 2011

ABSTRACTMandal and Lele (1989) have proposed a six dimensional model for the structural description of the decagonal phases. The integral linear combination of six basis vectors for indicating a physical vector in their model, however, leaves the problem of redundancy in indexing. While revisiting their model, we have noted that the condition of a null vector in physical space permits the formulation of unique indexing scheme both in physical reciprocal and direct spaces, we will demonstrate that our scheme, unlike all previously discussed ones, relies only on the information contained in the model. It will also be shown that diffracted spot having equivalent indices possesses identical intensity. This aspect, though equally important, has been totally ignored in the past. We shall substantiate our claim by taking examples from the known decagonal phases. We shall also present parity condition on indices that will be helpful in discussing subtle features of diffraction patterns. The notion of weak and strong diffracting conditions is explained based on the zone rule in physical space in terms of Cartesian components of direct and reciprocal vectors.
Electronic structure of Al-Cr-Fe intermetallics
Authors: Belin-Ferré Esther , Dankhazi Zoltan , Fontaine Marie-Françoise , Thirion Jean , de Weerd Marie-Cécile , Dubois Jean Marie 
Published: April 2011

ABSTRACTWe report here the results obtained for the valence band of four compounds from the Al-Cr-Fe system, all being approximants of the decagonal quasicrystalline phase as probed by a combination of X-ray emission and X-ray photoemission spectroscopy techniques. Salient features ared-dandp-dhybridizations at the Fermi level and in its close vicinity as well as a repulsive interaction between thedstates of the two transition elements. Within about 4 eV below the Fermi level Al states are suggested to be of more localized-like character in the Al-Cr-Fe samples than in Al-Cu-Fe ones.
Plasticity of decagonal Al73Ni10Co17 quasicrystals
Authors: Schall Peter , Feuerbacher Michael , Urban Knut 
Published: April 2011

ABSTRACTWe present a study of the deformation mechanism of decagonal Al73Ni10Co17 quasicrystals by means of transmission electron microscopy. We performed compression tests on single-quasicrystalline samples in three different orientations: with the compression axis parallel to, inclined by 45 ° and perpendicular to the tenfold axis of the decagonal quasicrystal. The deformed samples reveal characteristic orientation-dependent dislocation structures leading us to the conclusion that fundamentally different deformation mechanisms are involved in plastic deformation in the three deformation geometries. We explicitly identified the Burgers vectors of the dislocations as interatomic vectors in the structure of decagonal Al-Ni-Co.
Local Order in Single Grain Cd-Yb Icosahedral Phase
Authors: Wu Y. Q. , Kramer M. J. , Lograsso T. A. 
Published: April 2011

ABSTRACTSingle grains of icosahedral Cd84Yb16 quasicrystalline phase were characterized using high resolution transmission electron microcopy (HRTEM) technique. Image reconstruction of the obtained multiple through-focal series for both the two and five-fold axes are consistent with the local cluster structure of concentric polyhedra consisting of Cd tetrahedron (1/3 occupied icosahedron), Cd dodecahedron, Yb icosahedron and a Cd icosidodecahedron. Edge-sharing of the clusters can result in complete tiling of the 2-D projections. Simple matching rules are being investigated to construct a 3-D model.
Equilibrium structure of decagonal AlNiCo
Authors: Naidu S. , Mihalkovič M. , Widom M. 
Published: April 2011

ABSTRACTWe investigate the high temperature decagonal quasicrystalline phase of Al72Ni20Co8 using a quasilattice gas Monte-Carlo simulation. To avoid biasing towards a specific model we use an over-dense site list with a large fraction of free sites, permitting the simulation to explore an extended region of perpendicular space. Representing the atomic surface occupancy in a basis of harmonic functions directly reveals the 5-fold symmetric component of our data. Occupancy is examined in physical and perpendicular space.
Amorphisation and Devitrification of Al-Transition Metal- Rare Earth Alloys
Authors: Battezzati Livio , Baricco Marcello , Kusy' Martin , Palumbo Mauro , Rizzi Paola , Ronto' Viktoria 
Published: April 2011

ABSTRACTAmorphisation studies by rapid solidification of Al-based alloys containing a transition metal (TM) and a rare earth element (RE) are reported. Results on primary formation of Al nanocrystals are given and discussed in relation to possible nucleation mechanisms considering the effect of various RE elements (RE = La, Ce, Nd and Sm) in Al87Ni7RE6 alloys. Ti or Zr, immiscible with RE's, are added to the ternary alloys with the aim of revealing possible phase separation in the melt. Calculations of ternary Al-Ni-Ce metastable phase equilibria are helpful in understanding the transformation sequence. Composition profiles ahead of nanocrystals are computed using the DICTRA software which correctly predicts the occurrence of composition gradients.The surface fracture of mechanically tested samples are observed in TEM to check whether crystallisation is induced by deformation.
An isotropic glass phase in Al-Fe-Si formed by a first order transition
Authors: Cahn John W. , Bendersky Leonid A. 
Published: April 2011

ABSTRACTWe present evidence of the nucleation and growth of a metallic glass phase from the melt, as if by a first-order transition. Microstructures of a number of rapidly solidified Al-Fe-Si alloys demonstrate that this glassy phase, which we term q-glass, is not a kinetically frozen liquid. It is the first phase to form from the melt as isolated nuclei that grow and deplete the melt of iron and silicon. From the nucleation behavior and the compositional partitioning, we infer an interface between the q-glass and the melt, and that, in a narrow composition range, the q-glass has a lower energy and entropy (is more ordered) than a conventional glass.
The Mn effect on magnetic structure of FeMn-B amorphous metals
Authors: Wang Yang , Nicholson D. M. C. , Widom M. , Fuentes-Cabrera M. , Mihalkovic M. 
Published: April 2011

ABSTRACTFe-rich Fe-B amorphous metals exhibit approximately collinear magnetic structure. When a certain amount of Fe atoms are replaced with Mn, the magnetic structure of the alloys is found to become non-collinear. We performed electronic structure calculations using the locally self-consistent multiple scattering (LSMS) method for supercell samples generated by ab initio molecular dynamics simulation using the Vienna Ab-initio Simulation Package (VASP). We present the distribution of moment sizes and angular distributions in the FeMn-B amorphous metal samples. We discuss the Mn effect on the magnetic structure of the alloys.
The Prospects for Mechanical Ratcheting of Bulk Metallic Glasses
Authors: Wright Wendelin J. , Dauskardt R. H. , Nix W. D. 
Published: April 2011

ABSTRACTThe major mechanical shortcoming of metallic glasses is their limited ductility at room temperature. Monolithic metallic glasses sustain only a few percent plastic strain when subjected to uniaxial compression and essentially no plastic strain under tension. Here we describe a room temperature deformation process that may have the potential to overcome the limited ductility of monolithic metallic glasses and achieve large plastic strains. By subjecting a metallic glass sample to cyclic torsion, the glass is brought to the yield surface; the superposition of a small uniaxial stress (much smaller than the yield stress) should then produce increments in plastic strain along the tensile axis. This accumulation of strain during cyclic loading, commonly known as ratcheting, has been extensively investigated in stainless and carbon steel alloys, but has not been previously studied in metallic glasses. We have successfully demonstrated the application of this ratcheting technique of cyclic torsion with superimposed tension for polycrystalline Ti–6Al–4V. Our stability analyses indicate that the plastic deformation of materials exhibiting elastic–perfectly plastic constitutive behavior such as metallic glasses should be stable under cyclic torsion, however, results obtained thus far are inconclusive.
Synthesis and Characterization of Amorphous Metallic Alloy Thin Films for MEMS Applications
Authors: Sambandam Senthil N , Bhansali Shekhar , Bhethanabotla Venkat R. 
Published: April 2011

ABSTRACTMicrostructures of multi-component amorphous metallic glass alloys are becoming increasingly important due to their excellent mechanical properties and low coefficient of friction. In this work, thin films of Zr-Ti-Cu-Ni-Be have been deposited by DC magnetron sputtering in view of exploring their potential technological applications in fields such as Micro Electro Mechanical Systems (MEMS). Their structure, composition, surface morphology, mechanical properties viz., hardness and Young's modulus were analyzed using X-Ray Diffraction (XRD), Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM) and Nanoindentation. Influence of the deposition parameters of sputtering pressure and power upon the composition and surface morphology of these films has been evidenced by SEM, and AFM analysis, showing that such a process yields very smooth films with target composition at low sputtering pressures. These studies are useful in understanding the multicomponent sputtering process.
Deposition of Silver Nanoparticles on Yttrium Manganese Oxide Powders.
Authors: L. C. Roman , Castellanos R. M. A. , Diaz D. 
Published: April 2011

ABSTRACTFollowing a novel silver nanoparticles synthesis pathway, pre-synthesized silver nanoparticles (4.4 nm of average diameter) were deposited on a substrate of yttrium manganese oxide. The method takes advantage of the spontaneous reduction of silver 2-ethylhexanoate in dimethyl sulfoxide (DMSO) at 50° C. Sodium citrate was used as capping agent. Silver nanoparticles dispersions mixed with yttrium manganite were kept for several days, at room temperature, in an Erlenmeyer flask wrapped in aluminum foil. Pure yttrium manganese oxide was prepared by solid state reaction of stoichiometric mixtures. The characterization of the samples mainly involved X-ray powder diffractometry and electron microscopy. Magnetic susceptibility was measured using a Quantum Design MPMS-5S SQUID magnetometer. Two samples were prepared: (I) YMnO3/Ag (1×10-3 M) and (II) YMnO3/Ag (5×10-2 M). The Ag nanoparticles deposition of (I) was confirmed by an increase in the surface area and a qualitative elemental analysis for silver. In (II) <10 nm silver nanoparticles were clearly appreciated by XRD and images of High Resolution Transmission Electron Microscopy. The measured value of magnetic susceptibility of (II) is slightly larger than pure YMnO3.
Nano-Mechanical Study of Mechanically Alloyed Zr-Cu-Al-Ni Glass Composite Containing Second-Phase ZrC Particles
Authors: Alcalá Germán , Mato Sonia , Deledda Stefano , Knieps Martin , Hangen Ude , Eckert Jürgen , Gebert Annett , Schultz Ludwig 
Published: April 2011

ABSTRACTMetallic glasses exhibit generally high hardness and elastic modulus values at the expense of very limited plasticity. The incorporation of crystalline particles within an amorphous metallic matrix has been widely reported to improve the performance of these materials by reducing crack propagation. The present work analyzes the influence of nanometer-size ZrC particles on the nano-mechanical behavior of mechanically alloyed Zr55Cu30Al10Ni5 glassy matrix composites. The volume fraction of ZrC particles ranged from zero up to 20 vol. %, showing a critical change in the mechanical behavior between 10 and 20 vol. %, particularly in the elastic response.
A Survey of Defects in Strained Si Layers
Authors: Bedell S. W. , Chen H. , Sadana D. K. , Fogel K. , Domenicucci A. 
Published: April 2011

ABSTRACTA new method for highlighting defects in thin Si/SiGe layers is used to investigate the densities of various types of defects present in strained Si layers grown on relaxed SiGe layers. Defect densities were measured in strained Si layers formed on graded SiGe buffer layers (bulk), as well as silicon germanium-on-insulator substrates (SGOI), from both external and internal sources. The result of this investigation indicates that in addition to threading dislocations (TDs) and dislocation pile-ups, planar defects, i.e., stacking faults, are present in all but one of the materials studied. Due to the larger crystalline area affected by these planar defects, citation of only TD density as an indication of material quality is inadequate. A better measure of crystalline quality should include the density of TDs, pile-up clusters and planar defects (stacking faults) as well as some indication of the length distribution of the pile-ups and stacking faults.
Atomically Controlled Impurity Doping in Si-Based CVD Epitaxial Growth
Authors: Murota Junichi , Sakuraba Masao , Tillack Bernd 
Published: April 2011

ABSTRACTAtomic-order surface reaction processes on the group IV semiconductor surface are formulated based on the Langmuir-type surface adsorption and reaction scheme. In in-situ doped Si1−xGex epitaxial growth on the (100) surface in a SiH4-GeH4-dopant (PH3, or B2H6 or SiH3CH3)-H2 gas mixture, the deposition rate, the Ge fraction and the dopant concentration are explained quantitatively assuming that the reactant gas adsorption/reaction depends on the surface site materials and that the dopant incorporation in the grown film is determined by Henry's law. Self-limiting formation of 1-3 monolayers of group IV or related atoms in the thermal adsorption and reaction of hydride gases (SiH4, GeH4, NH3, PH3, CH4 and SiH3CH3) on Si(100) and Ge(100) are generalized based on the Langmuir-type model. Epitaxial Si or SiGe grown on N, P or B layers already-formed on Si(100) or SiGe(100) surface is achieved. It is found that higher level of electrical active P atoms exist in such film, compared with doping under thermal equilibrium conditions. Furthermore, the capability of atomically controlled processing for doping of advanced devices with critical requirements for dopant dose and location control is demonstrated for the base doping of SiGe:C heterojunction bipolar transistors (HBTs). These results open the way to atomically controlled technology for ultra-large-scale integrations.
Stress Metrology : The challenge for the next generation of engineered wafers
Authors: Tiberj Antoine , Paillard Vincent , Aulnette Cécile , Daval Nicolas , Bourdelle Konstantin K. , Moreau Myriam , Kennard Mark , Cayrefourcq Ian 
Published: April 2011

ABSTRACTRaman spectroscopy is a powerful and versatile technique for stress measurements in complex stacks of thin crystalline layers at macroscopic and microscopic scales. Using such a technique we show that thick SiGe layers epitaxially grown using graded buffer method are fully relaxed (>95%) at a macroscopic scale but exhibit a small strain modulation at a microscopic scale. For the first time we report the results of Raman micro-mapping of stress distribution in SGOI wafers produced by Smart Cut™ technology. We conclude that Smart Cut™ is a unique method to manufacture the next generation of engineered wafers that can combine strained and/or relaxed SiGe alloys, Si and Ge films, while keeping their initial strain properties at both scales. It is important to develop Raman spectroscopy tool for in-line process control in fabrication of strained Silicon On Insulator (sSOI) wafers.