Materials Literature
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High-purity ZnO nanowires, which possess branching structures, were prepared by evaporating metal zinc onto thermally oxidized Si wafer. The morphology and microstructure analyses of ZnO crystals were performed by scanning electron microscopy and high-resolution transmission electron microscopy. The nanowires possess…
Spallation neutron diffraction and high-energy x-ray diffraction methods have been used to study CaO:Al 2 O 3 glasses at the 64:36 mol% eutectic and 50:50 mol% compositions. The samples were produced by the containerless cooling of liquid droplets heated by a laser beam and suspended in an aerodynamic levitator. The r…
The authors report ${}^{13}\mathrm{C}$ NMR and magnetization measurements on the magnetic state of oriented single crystals of the organic superconductor $\ensuremath{\kappa}\ensuremath{-}(\mathrm{BEDT}\ensuremath{-}\mathrm{TTF}{)}_{2}\mathrm{Cu}[\mathrm{N}(\mathrm{CN}{)}_{2}]\mathrm{Cl}.$ To understand these data a s…
Ternary (Ge 2 X 3 ) x (As 2 X 3 ) 1− x glasses with X = S or Se are of interest because they span a mean coordination number r in the 2.40 < r < 2.8 range that is characteristic of stressed–rigid glasses. We have examined X = S glasses in Raman scattering and T -modulated differential scanning calorimetry measurements…
Photocatalytic oxidation of CO to CO 2 was carried out with TiO 2 and Pt/TiO 2 catalysts at room temperature to investigate the effect of Pt deposition. The rate for CO photooxidation by Pt/TiO 2 was higher than that by TiO 2 . The reaction rate increased with incident light intensity to the power of 0.7 for Pt/TiO 2…
New poly(methacrylamide)s containing oligoaniline side chains were synthesized and characterized. Oligoanilines were prepared by palladium-catalyzed amination, followed by reaction with methacryloyl chloride to give methacrylamide monomers. Polymers were prepared by free radical polymerization. The polymers were prepa…
The ability to control the size and shape of nanoparticle assemblies is essential for the ultimate applications in sensors, catalysis, medical diagnostics, information storage, and quantum computation. This report demonstrates a novel mediator-template strategy toward this ability by exploring molecular driving forces…
A soluble photoreactive polyimide (PSPI) with side-group cinnamate (CI) chromophores that forms good quality films through conventional solution spin-casting and drying processes was successfully synthesized with a reasonably high molecular weight: poly(3,3‘-bis(cinnamoyloxy)-4,4‘-biphenylene hexafluoroisopropylidened…
Geometric parameters of NiO films epitaxially grown on Ag(001) were determined using two independent experimental techniques and ab initio simulations. Primary beam diffraction modulated electron emission experiments determined that the NiO films grow with O on top of Ag and that the oxide/metal interface distance is…
A new method for the preparation of SiO 2 /ZnO composite nanoparticles by the simplified controlled double-jet precipitation technique is described. The transmission electron microscopic and scanning electron microscopic images of SiO 2 /ZnO show that ZnO is coated on the silica (SiO 2 ) surface as a thin layer or sin…
The crystallization and the melting of vulcanized isoprene rubber under uniaxial deformation have been studied by the measurements of the stress−strain−temperature relation. The melting temperature increases approximately linearly with nominal stress for the rubbers crystallized at a fixed temperature and stress condi…
Protein kinases are important enzymes controlling the majority of cellular signaling events via a transfer of the gamma-phosphate of ATP to a target protein. Even after many years of study, the mechanism of this reaction is still poorly understood. Among many factors that may be responsible for the 1011-fold rate enha…
Dense and homogeneous grafted polymer layers were anchored from the melt onto a silicon wafer modified with a macromolecular anchoring layer rich in epoxy functional groups. A monolayer of poly(glycidyl methacrylate) (PGMA), attached to silicon wafers, served as the macromolecular anchoring layer. Carboxylic acid- and…
We performed ab initio calculations of the anisotropic dielectric response of small-diameter single-walled carbon nanotubes in the framework of time-dependent density-functional theory. The calculated optical spectra are in very good agreement with experiment, both concerning absolute peak positions and anisotropy eff…
Nanocavities in Ge(111) created by 5 keV Xe ion irradiation are characterized by ex situ transmission electron microscopy and Rutherford backscattering spectrometry. Nanocavities nucleate near the surface and then undergo thermal migration. Nanocavities with average diameter of 10 nm and areal density of 5.1 x 10-3 nm…
An overview of recent studies on ferromagnetism in Cr- and Mn-based II-VI diluted magnetic semiconductors is presented emphasizing differences in underlying exchange mechanisms. Examples of manipulations with spin ordering by carrier density, dimensionality, light, and electric field are given.
We present a theoretical study of the ballistic magnetoresistance in Ni contacts using first-principles, atomistic electronic-structure calculations. In particular we investigate the role of defects in the contact region in order to explain the recently observed spectacular magnetoresistance ratio. Our results predict…
When a solid such as iron is cooled across a structural transition, its final microstructure depends sensitively on the cooling rate and the depth of quench. For instance, an infinitesimally slow cooling or a shallow quench results in an equilibrium "ferrite," while a rapid cooling or a deep quench gives rise to a met…
Abstract Electrical and mechanical property tests have been used to examine the changes in the carbon black network structure that occur in a filled elastomer at large strains in tension and compression. These changes have been examined both in materials that have no previous loading history and in test pieces that ha…
We investigate the temperature dependence of the resistivity and magnetoresistance of a polycrystalline $Sr_2CoMoO_{6-δ}$ film deposited on (100)-$SrTiO_3$ substrate prepared by the pulsed laser deposition method. X-ray diffraction, Raman and magnetoresistance results demonstrate clearly the coexistence of a ferromagn…