Materials Literature
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A solid-state quantum computer with dipolar coupling between qubits is proposed. The qubits are formed by the low-lying states of an isolated acceptor in silicon. The system has the scalability inherent to spin-based solid state systems, but the spatial separation between the qubits is an order of magnitude larger. De…
The electron spin is emerging as a new powerful tool in the electronics and optics industries. Many proposed applications involve the creation of spin currents, which so far have proven to be difficult to produce in semiconductor environments. A new theoretical analysis shows this might be achieved using holes rather…
In this study, a novel ultrasonically initiated in situ emulsion polymerization approach was used to modify multi-walled carbon nanotubes (MWCNTs). The dispersion behavior of MWCNTs in aqueous solution under ultrasonic irradiation was investigated by spectrophotometry. Ultrasonically initiated emulsion polymerization…
We investigate the nitrogen substitutional impurity in semiconducting zigzag and metallic armchair single-wall carbon nanotubes using ab initio density functional theory. At low concentrations (less than 1 at. %), the defect state in a semiconducting tube becomes spatially localized and develops a flat energy level in…
The aim of this paper is to describe the possibility of achieving super-hydrophobic materials by tailoring their surface topography. Water droplets easily slip or roll down on such surfaces. However, it is found that microtextures on a solid can generate sticky surfaces as well, and the conditions for avoiding such an…
Au-nanoclusters between 2 and 8 nm in diameter were deposited onto solid substrates in different pattern geometries. The basis of this approach is the self-assembly of polystyrene- b -poly[2-vinylpyridine (HAuCl 4 )] diblock copolymer micelles into uniform monomicellar films on solid supports such as Si-wafers or glas…
A layered compound composed of crystalline ruthenic acid sheets interleaved with layers of water can be exfoliated (delaminated) to yield colloidal nanosheets. This material is a mixed conductor where the crystalline nanosheets contribute to the electron conductivity and the hydrous interlayer supplies proton transpor…
Electro-optic (EO) polymeric Mach-Zehnder (MZ) modulators with photo-bleaching (PB) induced waveguides and dual driving electrodes operating at 1.55 µm wavelength have been demonstrated. The half-wave voltage of the integrated polymeric modulator was 4.5 V in a push–pull configuration with a 1.5 cm interaction length.…
Insider report: A fluoroleucine mutant of ubiquitin (cyan) with two strategically placed fluorine reporter groups in its core was synthesised. 1H NMR, crystallography, CD spectroscopy, biological assay and calorimetry indicate minimal structural and functional perturbation compared to the native protein (yellow; see p…
We present electronic structure calculations of manganese mononitride (MnN) in its tetragonally distorted NaCl structure using density-functional theory within the generalized gradient approximation. The structure with an antiferromagnetic arrangement of the spins on the Mn ions is found to be the energetically stable…
Techniques have been developed to culture bovine or porcine vascular cells on polyglycolic acid (PGA) scaffolds to form engineered vessels. Previously, it was shown that smooth muscle cells (SMCs) that were in close proximity to PGA remnants after 8 weeks of culture had lower expression of SMC markers of differentiati…
The evolution of stresses in a heteroepitaxial $({\mathrm{Ba}}_{0.7}{\mathrm{Sr}}_{0.3}){\mathrm{TiO}}_{3}/(001)\mathrm{MgO}$ thin film was studied by means of micro-Raman spectroscopy. A small part of the substrate was gradually dissolved, then partially unsupported and completely free-standing areas of the film were…
Solid-state preparation, structure, and multi-colour luminescence of Eu 2+ doped strontium aluminate (SRA) phosphors have been reported in this paper. It has been observed that a slight modification in the processing parameters such as type of reducing atmosphere, stoichiometric excess of one or more constituents, nat…
Effects of mixing of magnetic states in a molecular ${\mathrm{Cr}}_{8}$ ring were investigated by torque magnetometry and heat capacity measurements. Results are interpreted within the framework of the spin Hamiltonian approach allowing us to fit the pattern of energy levels derived by neutron spectroscopy. The torque…
A novel, high-efficiency detector for neutral atoms such as helium is described. The design uses multiwalled carbon nanotubes (MWNTs), grown by chemical vapor deposition on a steel support wire. Application of a positive bias to the MWNTs generates electric fields sufficient to field-ionize passing gas-phase atoms. Un…
Materials for thermoelectric application should have low lattice thermal conductivities. Here we use a comparison of theoretical calculations and Raman spectroscopy to study the lattice dynamics of a La filled skutterudite and identify the Raman active modes. Polarized Raman spectra from polycrystalline ${\mathrm{La}}…
A six-dimensional cluster model of icosahedral Al-Pd-Mn $(i\ensuremath{-}\mathrm{Al}\ensuremath{-}\mathrm{Pd}\ensuremath{-}\mathrm{Mn})$ quasicrystals used in the recent structure refinement is described in detail. This model is based on five kinds of clusters located at vertices, edge centers of the inflated three-di…
A comprehensive analysis of half-doped manganites is presented using Monte Carlo simulations applied to the double-exchange model with cooperative Jahn-Teller lattice distortions in two dimensions. A variety of results are reported. In particular (i) The phase diagram is established in the $\ensuremath{\lambda}\ensure…
The phase behavior of aqueous mixtures of poly(ethylene oxide) (PEO) and dextran is studied as a function of the polymer concentration, the PEO molar mass, and temperature. The molar mass distributions of the two polymers in the coexisting phases are measured. From the temperature dependence we conclude that the phase…
A surface modification technique was developed for the covalent immobilization of heparin onto electrically conductive polypyrrole (PPY) film. The PPY film was first graft copolymerized with poly(ethylene glycol) methacrylate (PEGMA) and then activated with cyanuric chloride (CC). Heparin was then immobilized onto the…