bluuebunny/crossref_metadata_2025_split huggingface dataset:
Measurement of Mechanical Properties in Small Dimensions by Microbeam Deflection
Authors: Kraft O. , Schwaiger R. , Nix W.D. 
Published: April 2011

AbstractIn this paper, we describe a technique for measuring elastic and plastic properties of thin films by microbeam deflection. The test procedure is similar to a macroscopic bending test where an external load is applied to a beam and its bending measured. Silicon oxide microbeams were made by different growth, lithography and etching techniques. The beams were then deflected with a nanoindenter, while the applied load and the displacement of the beam were recorded. Young's modulus was determined from the initial linear load-displacement behavior. Some beams were notched using a focused ion beam technique and loaded until brittle fracture occurred. These measurements permit the determination of the fracture toughness of the beam materials. In order to study plastic deformation in thin Ag films, the method was extended by depositing films onto the beams and measuring the behavior of the beam/film composite. Yielding of the Ag film was seen as a deviation from the linear-elastic behavior of the beam.
Amine Templated Zinc Phosphates Phases for Membrane Separations
Authors: Nenoff Tina M. , Chavez Alejandra V. , Thoma Steven G. , Provencio Paula , Harrison William T. A. , Phillips Mark L. F. 
Published: April 2011

AbstractOur research is focused on developing inorganic molecular sieve membranes for light gas separations such as hydrogen recovery and natural gas purification, and organic molecular separations, such as chiral enantiomers. We focus on zinc phosphates because of the ease in crystallization of new phases and the wide range of pore sizes and shapes obtained. With our hybrid systems of zinc phosphate crystalline phases templated by amine molecules, we are interested in better understanding the association of the template molecules to the inorganic phase, and how the organic transfers its size, shape, and (in some cases) chirality to the bulk. Furthermore, the new porous phases can also be synthesized as thin films on metal oxide substrates. These films allow us to make membranes from our organic/inorganic hybrid systems, suitable for diffusion experiments. Characterization techniques for both the bulk phases and the thin films include powder X-ray diffraction, TGA, Scanning Electron Micrograph (SEM) and Electron Dispersive Spectrometry (EDS).
On-Line Spectroscopic Studies of Group iv Alkoxides and their Interactions with Polymerizable Organic Additives During the Sol-Gel Process
Authors: Cinier R. , Guilment J. , Poncelet O. , Truchet S. , Wettling D. 
Published: April 2011

AbstractThe monitoring of different reactions such as the stabilization of the alkoxides with polymerizable organic additives, the building of the inorganic network during the hydrolysis process, and in a same manner, the polymerization of the organic additives, can be of great importance for the development of hybrid materials with improved processability.NIR spectroscopy is a very versatile technique but lacks of specificity. IR and Raman give more interpretative results but are not always easy to run on a process. We used both techniques along with chemometric tools to extract relevant information from our processes. Then 2D correlation allowed to benefit from the specificity of IR and Raman to develop robust NIR methods able to be used on line to control the different steps of the sol-gel process.The hydrolysis of mixed species of titanium containing chloro, isopropoxo and methacrylato ligands will be discussed in terms of mechanism occuring during the sol-gel process.
Characterization of Dendrimer-Based Nanocomposites by Saxs and Sans
Authors: Tan N. C. Beck , Balogh L. , Trevino S. F. , Tomalia D. A. , Lin J. S. 
Published: April 2011

AbstractDendritic polymers have been used as soluble templates/unimolecular reactors from which nano-clusters of inorganic compounds were synthesized. These organic/inorganic, dendrimerbased hybrid species or “nanocomposites” display unusual properties, i.e., their solubility is deterrnined by the properties of the dendrimer molecules. Since it has been established that there is no covalent bond between the dendrimer host and the inorganic guest, these observations suggest that the guests are physically and spatially restricted by the dendrimer shell. However, this structure has not been verified. In this investigation a preliminary understanding of the physical structure of these dendrimer-based nanocomposites was sought. A model system of PAMAM dendrimer-copper sulfide nanocomposites was studied in various stages of its formation using a combination of small angle X-ray and neutron scattering experiments. The results suggest that little perturbation of the dendritic species occurs on complexation, but indicate that a secondary supermolecular aggregation phenomena occurs within nanocomposite solutions.
Hybrid Materials : Intricate Structures Guiding Complex Dynamics
Authors: Judeinstein P. 
Published: April 2011

AbstractThe structure and certain properties of Class {I} and Class {II} nanocomposites based on silica-poly(ethylene)oxide blends are described herein. The detailed structure of the silica framework of Class {I} materials is depicted by combining 29Si NMR and X-Ray diffractometry, while the properties of the polymer phase are obtained from 13C NMR and thermal analysis (DSC). These experiments demonstrate the significant influence of the catalyst on the silica structure (compositional and positional disordering). Moreover, the dynamic properties of the polymer phase are greatly effected by the silica morphologies (silica surface area and degree of phase interpenetration). Class {II} materials were also studied. They have rubbery properties and can be used as a matrix to absorb large quantities of solvents. Hence, combining uniaxial anisotropy (through unidirectionnal strain) with deuterated molecules enabled the study of these materials by quadrupolar NMR. This technique is very sensitive to the local anisotropy of the samples used and leads to a better understanding of supramolecular interactions between probe and host polymer.
Organic Dye-Doped Hybrid Sol-Gel Coatings and Pigments – Synthesis, Structural Elucidation and Application
Authors: Schottner G. , Hofacker S. , Sandrock J. 
Published: April 2011

AbstractThe chemistry of sol-gel processing of dye-doped, hybrid coatings for glass surfaces has been studied via FT-Raman-, NIR- and NMR-spectroscopy both in the liquid and solid state. Based on these results further investigations are presented aiming at the development of new hybrid pigments by spray drying of two-component sols. The properties of the resulting powders are discussed with respect to their morphology, migration behaviour and photostability.
Photoluminescence of Eu3+:Y2O3 Nanoclusters Embedded in SiO2 Glass
Authors: Jia Weiyi , Wang Yanyun , Santiago Miguel , Castro Limari , Liu Huimin , Claflin B. , Lucovsky G. 
Published: April 2011

AbstractEu3+(1at%) doped and Eu3+"(1at%), Y3+(10at%) codoped SiO2 glasses were prepared by sol-gel technology. Dominant red emission at 615 nm from 5D0to 7F2of Eu3+ was observed from both samples annealed above 800 °C. The intensity of luminescence of Eu, Y codoped samples is three times stronger than that of Eu doped samples. The lifetime of the former is two times longer than the latter. An analysis indicates that in the sample of Eu, Y codoped SiO2 glass, Eu3+ ions stay in the Y2O3 nanoclusters, which were formed during the annealing process and embedded in SiO2.
Hybrid Materials Made by Polymerization of the Nanobuilding Blocks {(BuSn)12O14,(OH)6,}2+(AAMPS−)2 (AAMPS = 2-acrylamido-2-methyl-l-propanesulfonate)
Authors: Ribot F. , Eychenne-Baron C. , Sanchez C. 
Published: April 2011

AbstractThe reaction of {(BuSn)12014(OH)6}(OH)2 and 2-acrylamido-2-methyl-1-propanesulfonic acid yields bifunctional nanobuilding blocks, {(BuSn)12,014(OH)6)(AAMPS)2, which carry highly polymerizable acrylamido groups. In such species, the functionalization with polymerizable groups is achieved through electrostatic interaction; the charge compensating anions AAMPS− being located at both poles of the {(BuSn)12O14(OH)6}2+ macrocation. Free radical polymerization of these nanobuilding blocks in THF yields an insoluble material. Solid state 13C CP-MAS NMR of the insoluble fraction (∼70%) indicates that the polymerization of the acrylamido groups is complete. Solid state 119Sn MAS NMR shows that the oxo-hydroxo butyltin core of the nanobuilding blocks is fully preserved in the final material.
The Cubeoctameric Silicate Anion: Formation and Application to Porous Material Synthesis
Authors: Hasegawa Isao 
Published: April 2011

AbstractThe cubeoctameric silicate anion is one of compounds which can be used as a building block for constructing nanostructures of materials. This paper deals with the synthesis and reactivity of the silicate anion and organic-inorganic hybrid and inorganic multi-component porous materials produced from the anion.
Novel Uv-Curable Low-Shrinking Silanes as Precursors for the Sol-Gel-Process
Authors: Stein S. , Moszner N. , Voelkel Th. , Rheinberger V. 
Published: April 2011

AbstractThe increasing interest in inorganic-organic nanocomposites which offer the possibility to build up both an inorganic and organic network by hydrolysis and condensation and by polymerization reactions, respectively, leads to the development of a new class of double bond functionalized silanes. These 2-vinylcyclopropyl silanes were synthesized e.g. by reaction of 1-methoxycarbonyl-2-vinylcyclopropane-l-carboxylic acid with 3-isocyanatopropyltriethoxysilane. Hydrolysis and condensation of the alkoxy groups as well as cocondensation with tetraalkoxysilanes lead to solvent-free liquid resins that can be cured by UV-light-induced radical polymerization of the vinylcyclopropane group. The synthesis and characterization of different 2-vinylcyclopropyl silanes, hydrolysation and condensation behavior and first results of the radical polymerization will be discussed.
Microwave Assisted Blending-Intercalation of Ion-Conductor Polymers into Layered Silicates
Authors: Aranda P. , Galván J.C. , Ruiz-Hitzky E. 
Published: April 2011

AbstractOrgano-inorganic hybrid nancomposites derived from poly(ethylene oxide) and montmorillonite silicate are prepared by an alternative procedure to classical polymer intercalation either from solutions or by polymer melt-intercalation. XRD, FTIR, DSC, elemental microanalysis and SEM techniques are applied for structural characterization of the resulting materials. The electrical properties of these nanocomposites are studied by means of the electrical impedance spectroscopy (EIS) showing enhanced ionic conductivity compared to similar samples prepared by intercalation from solution.
Systematic Approach to the Synthesis of Organic-Inorganic Nanocomposites Based on Dmta Measurements and Ir Spectroscopy
Authors: Müller Peter , Becker Carsten , Schmidt Helmut 
Published: April 2011

AbstractSol-gel derived organic-inorganic hybrid materials with potential fields of application as refractive optical components for example laser diode bars and ophthalmic lenses are presented. The main components of the hybrid materials under investigation are precondensed methacryloxypropyltrimethoxysilane (MPTS, denoted: M) with an organically polymerisable methacrylic functionality and tetraethyleneglycoldimethacrylate (TEGDMA, denoted: T) as crosslinking organic monomer with two polymerisable double bonds. The molar ratios of the components ranged from M/T 10/90 up to M/T 70/30. The polymer derived from pure TEGDMA (M/T 0/100) served as a reference material. In addition to this nanoscaled TiO2 particles (5 wt.% and 10 wt.%) were incorporated in the organic-inorganic M/T 30/70 matrix to increase the refractive index of the resulting nanocomposites. For the preparation of the different systems, precondensed MPTS was mixed with TEGDMA, the nanoparticulate titania sol (when used), an appropriate photoinitiator and a thermoinitiator. The reaction mixtures were polymerised photochemically and/or thermally. The propagation of the free radical polymerisation reaction after photopolymerisation and subsequent thermal curing was followed by IR-spectroscopy, showing that the degree of double bond conversion is strongly increased by the thermal curing step. Incorporation of increasing amounts of TiO2 nanoparticles resulted in reduction of the double bond conversion compared to the corresponding unfilled system. The homogeneous dispersion of the titania particles in the completely cured M/T 30/70 matrix could be manifested by high resolution transmission electron microscopy (HTEM). The thermomechanical properties of the completely cured nanocomposites were monitored by dynamic mechanical thermal analysis (DMTA) showing a strong dependence on composition.
Investigation of Transition Metal-Xanthate Complexes for Nonlinear Optical Applications
Authors: Zelmon David E. , Gebeyehu Zewdu , Tomlin David , Cooper Thomas M. 
Published: April 2011

AbstractWe have synthesized several metal xanthate complexes from metal salts and xanthate potassium salts. Powders of several of the materials were sorted and tested for their nonlinear optical properties. Cadmium xanthate demonstrated phase matchability for frequency doubling of 1.06 micron light and generated a very strong second harmonic signal.
Incorporation of Siloxane And Cyclophosphazene Units Into Metal Oxides by a Nonhydrolytic Sol-Gel Route
Authors: Crouzet L. , Leclercq D. , Mutin P. H. , Corriu R. J. P. , Vioux A. 
Published: April 2011

AbstractA nonhydrolytic sol-gel method was used to incorporate siloxane and cyclotriphosphazene units within metal oxides. The degree of mixing of the components was investigated by EDX, XPS, and 29Si and 31P solid-state NMR. The NMR data confirmed the presence of Si-O-M and PO- M bonds.
Self-Assembly of Organic-Inorganic Nanocomposite Coatings that Mimic the Structure of Shell
Authors: Sellinger Alan , Weiss Pilar M. , Nguyen Anh , Lu Yunfeng , Assink Roger A. , Brinker C. Jeffrey 
Published: April 2011

AbstractAfter over a decade of research, the efficient synthesis and processing of layered organic/inorganic nanocomposites that mimic bone and shell structures remains an elusive goal of the materials chemist. We report on a rapid, efficient, continuous method to form layered nanocomposites via evaporation induced supramolecular self-assembly (SSA). During dip coating of a homogeneous sol containing alcohol or ether solvents, silica precursors, organic monomers, initiators and surfactant (at an initial concentration below cmc), solvent evaporation induces the formation of micellar structures that co-organize with silica to form cubic, hexagonal or lamellar mesophases. The organic monomers and initiators are solvated within the hydrophobic micellar interiors. Subsequent photo or thermal polymerization and washing results in a silica/polymer thin film nanocomposite. The microstructural and physical characteristics of these materials will be discussed in the context of potential applications as abrasion resistant coatings and optical hosts.
Preparation of Tem Plan View Sections on Specific Devices Using the Tripod Polisher
Authors: Benedict J. P. , Anderson R. M. , Klepeis S. J. 
Published: April 2011

AbstractPlan view or “top down” sections of specific sites for TEM analysis can be prepared by mechanically polishing the specimen with the Tripod Polisher. This technique produces plan view sections with a large area available for TEM analysis that encompasses the specific site. Because the sample is mechanically polished, the problem of surface topography due to non uniform thinning is minimized.
Dislocations in InAs Epilayers Grown by MBE on GaAs Substrates Under Various Conditions
Authors: Wang Hongmei , Zeng Yiping , Pan Liang , Zhou Hongwei , Zhu Zhanping , Kong Meiying 
Published: April 2011

AbstractUsing Transmission Electron Microscopy, we studied the misfit and threading dislocations in InAs epilayers. All the samples, with thickness around 0.5μm, were grown on GaAs(001) substrates by molecular beam epitaxy under As-rich or In-rich conditions. The As-rich growth undergoes 2D-3D mode transition process, which was inhibited under In-rich surface. High step formation energy under As-deficient reconstruction inhibits the formation of 3D islands and leads to 2D growth. The mechanism of misfit dislocations formation was different under different growth condition which caused the variation of threading dislocation density in the epilayers.
Ordering in Compound Semiconductors: The Role of Transmission Electron Microscopy
Authors: Su D. S. , Tham A. T. , Schubert-Bischoff P. , Hähnert I. , Neumann W. , Giersig M. , Zeitler E. 
Published: April 2011

AbstractIn this paper, the ordering of ternary semiconductor compounds is briefly reviewed by means of a coordination polyhedron model. Long-range ordering of chalcopyrite and CuAu-type structures can be represented as an array of repeating A2B2 tetrahedra. A CuAu-type ordered phase in a chalcopyrite AIBIIICVI2 compound is surrounded by an A3B+ AB3 boundary, whereas a CuPt-type ordered phase in a zinc-blende (A, B)IIICV compound is surrounded mainly by A2B2 type tetrahedra and thus restricted in size. Following the description of the ordered structure model, the detection of the asymmetry in ordering directions in (A, B)IIICV compounds is discussed. Some examples that employ transmission electron microscopy are presented.
In Situ Monitoring of the Electrochemical Absorption of Deuterium into Palladium by X-Ray Diffraction using Synchrotron-Wiggler Radiation
Authors: Dominguez D. D. , Hagans P. L. , Skelton E. F. , Qadri S. B. , Nagel D. J. 
Published: April 2011

ABSTRACTWith low energy x-rays, such as those from a Cu x-ray tube, only the outer few microns of a metallic sample can be probed. This low penetrating power prohibits structural studies from being carried out on the interior of an electrode in an electrochemical cell because of absorption by the cell material, electrodes and the electrolyte. The work described in this paper circumvents this problem by utilizing high energy, high brightness x-rays produced on the superconducting wiggler beam line, X-17C, at the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory. The penetrating power of the higher energy x-rays allowed Pd diffraction spectra to be obtained in-situ on a 1 mm diameter Pd wire cathode during electrolysis of heavy water. Moreover, the beam (28 × 28 μm in cross-section) allowed diffraction spectra to be acquired as a function of distance across the sample. Spectra were recorded in 50 μm steps from the edge of the Pd wire to its core. This was done at 2 minute intervals as a function of electrolysis time. The α-β phase transition induced in the Pd while deuterium was electrochemically absorbed was observed by monitoring the Pd-(422) diffraction peaks. Results allowed the diffusion rate and the diffusivity of deuterium atoms in the Pd wire to be determined. Other features of the structural changes associated with the absorption of deuterium into Pd are reported.
High Pressure Synchrotron Diffraction of KCa2Nb3O10, a Layered Perovskite Compound
Authors: Steiner K. A. , Petuskey W. T. 
Published: April 2011

ABSTRACTHigh pressure synchrotron x-ray diffraction experiments were conducted on KCa2Nb3O10, to determine lattice constants as a function of pressure. A diamond anvil cell was used to produce pressures up to 66 GPa. A phase transition occurred at 13.5 GPa. From the lattice constants, linear compressibilities of 8.55 × 10-4 GPa-1 in the a direction, -9.40 × 10-4 GPa-1 in the b direction, and 142 × 10-4 GPa-1 in the c direction, and a bulk modulus of 68.5 GPa were found for the lower pressure orthorhombic phase.
Comparison Of A Mosaic-Crystal Spectrometer To Ahigh-Performance Solid-State Detector For X-Ray Microfluorescence Analysis
Authors: Chung J.-S. , Isa S. , Sparks C. J. , Ice G. E. , Mchugo S. , Thompson A. 
Published: April 2011

ABSTRACTThe minimum-detectable-limit of a compact double-focusing graphite mosaic-crystal spectrometer is compared to the minimum-detectable-limit from a high-performance Ge solidstate detector. The solid angle and efficiency of the solid-state detector is much greater than for the crystal spectrometer. However, the better signal-to-noise of the spectrometer and its insensitivity to matrix fluorescence and scattering can give it a better minimum-detectable-limit for trace element analysis. The relative advantages of the two detectors are illustrated for some simple test samples. The performance of the crystal spectrometer compared to the solid-state detector increases as the flux in the x-ray probe increases. This makes crystal spectrometers especially interesting for use with new high intensity 3rd generation synchrotron microprobes. An estimate is made of the source and sample conditions favored for each detector.
Spectroscopic Studies of Low Dielectric Constant Fluorinated Amorphous Carbon Films for Ulsi Integrated Circuits
Authors: Ma Yanjun , Yang Hongning , Guo J. , Sathe C. , Agui A. , Nordgren J. 
Published: April 2011

ABSTRACTPerformance of future generations of integrated circuits will be limited by the RC delay caused by on-chip interconnections. Overcoming this limitation requires the deployment of new high conductivity metals such as copper and low dielectric constant intermetal dielectrics (IMD). Fluorinated amorphous carbon (a-CFx) is a promising candidate for replacing SiO2 as the IMD. In this paper we investigated the structure and electronic properties of a-CFx thin films using high-resolution x-ray absorption, emission, and photoelectron spectroscopy. The composition and local bonding information were obtained and correlated with deposition conditions. The data suggest that the structure of the a-CFx is mostly of carbon rings and CF2 chains cross-linked with C atoms. The effects of growth temperature on the structure and the thermal stability of the film are discussed.
The Spin Polarized Band Structure of Strained Thin Films of Gadolinium
Authors: Waldfried C. , Dowben P.a , Vescovo E. 
Published: April 2011

ABSTRACTThe magnetic properties of strained thin films of gadolinium are characterized by a wave vector and thickness dependence of the exchange splitting. The spin-resolved band structure has been mapped by spin polarized photoemission, and provides considerable insight into the relationship between magnetism of local moment systems, and band structure.
Chemical Analysis of Particles and Semiconductor Microstructures by Synchrotron Radiation Soft X-Rays Photoemission Spectromicroscopy
Authors: Gozzo F. , Triplett B. , Fujimoto H. , Ynzunza R. , Coon P. , Ayre C. , Kinney P. D. , Uritsky Y. S. , Ackermann G. , Johnsono A. , Padmore H. , Renner T. , Sheridan B. , Steele W. , Hussain Z. 
Published: April 2011

ABSTRACTChemical analysis on a microscopic scale was performed on a TiN particle sample on silicon and on two patterned samples using a synchrotron source scanning photoemission microscope. For all the experiments, we exploit the ability, developed in our experimental system, to reach specific locations on the wafer and analyze the local chemical state.
Characterizing Trace Metal Impurities in Optical Waveguide Materials Using X-Ray Absorption
Authors: Citrin P. H. , Northrup P. A. , Atkins R. M. , Glodis P. F. , Niu L. , Marcus M. A. , Jacobson D. C. 
Published: April 2011

ABSTRACTX-ray absorption measurements are described for identifying metal impurities in
silica preforms, the rod-like starting materials from which hair-like optical fibers are drawn.
The results demonstrate the effectiveness of this approach as a non-destructive,
quantitative, element-selective, position-sensitive, and chemical-state-specific means for
characterizing transition metals in the concentration regime of parts per billion.