Materials Literature
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For the first time, MnCr 2 O 4 spinel single-crystalline nanowires were simply synthesized by heating commercial stainless steel foil (Cr 0.19 Fe 0.70 Ni 0.11 ) under a reducing atmosphere. The nanowires have an average diameter of 50 nm and a length of about 10 μm. Some nanowires are sheathed with a thin layer of amo…
The thermal reactions of N-fused tetraarylporphyrins or N-confused tetraarylporphyrins with Re2(CO)10 gave the rhenium(I) tricarbonyl complexes bearing N-fused porphyrinato ligands (4) in moderate to good yields. The rhenium complexes 4 are characterized by mass, IR, 1H, and 13C NMR spectroscopy, and the structures of…
The ultrastructure of isolated fibrils of Chondrosia reniformis sponge collagen was investigated by collecting characteristic data, such as fibril thickness, width, D-band periodicity, and height modulation, using atomic force microscopy (AFM) and transmission electron microscopy (TEM). Therefore an adapted pre-proces…
We demonstrate three-dimensional vibrational imaging of director structures in liquid crystals using coherent anti-Stokes Raman scattering (CARS) polarized microscopy. Spatial mapping of the structures is based on sensitivity of a polarized CARS signal to orientation of anisotropic molecules in liquid crystals. As an…
In this paper we propose and discuss coherent terahertz sources based on charge density wave (plasmon) amplification in two dimensional graphene. The coupling of the plasmons to interband electron-hole transitions in population inverted graphene layers can lead to plasmon amplification through stimulated emission. Pla…
Degradation and relaxation studies have been performed on two polystyrene (PS)-montmorillonite clay nanocomposites, one of which has an intercalated PS-clay structure and the other an exfoliated PS-clay brush structure. Compared to virgin PS, both nanostructured materials have demonstrated the following similarities:…
Alkanethiol-capped gold nanoparticles dispersed in n-dodecane were studied by spectroscopic ellipsometry and were modeled using Mie scattering theory. The refractive index in the visible and near-infrared depended on the volume fraction of gold nanoparticles, in good agreement with the theoretical expectation that suc…
Impurity effects on the stability of a ferromagnetic-metallic state in a bicritical-state manganite, ${({\mathrm{La}}_{0.7}{\mathrm{Pr}}_{0.3})}_{0.65}{\mathrm{Ca}}_{0.35}\mathrm{Mn}{\mathrm{O}}_{3}$, on the verge of metal-insulator transition have been investigated by substituting a variety of transition-metal atoms…
We describe the structure, activity, and stability of enzymes covalently attached to single-walled carbon nanotubes (SWNTs). Conjugates of SWNTs with three functionally unrelated enzymes-horseradish peroxidase, subtilisin Carlsberg, and chicken egg white lysozyme-were found to be soluble in aqueous solutions. Furtherm…
An experimental tour de force reveals the crystal structure of a gold-thiolate nanocrystal compound and the surprising nature of the gold-sulfur bonding.
β-Ni(OH) 2 carnationlike structures assembled from nanosheet building blocks were successfully synthesized via a hydrothermal method through the hydrolysis of nickel acetate in mixed solvents of water and glycerol. NiO carnations assembled from nanosheets with nanopores were obtained by thermal decomposition of the as…
The properties of epitaxial Bi2FeCrO6 thin films, recently synthesized by pulsed laser deposition, have partially confirmed the theoretical predictions (i.e. a magnetic moment of 2 muB per formula unit and a polarization of ~80 microC/cm2 at 0K). The existence of magnetic ordering at room temperature for this material…
The present approach to SERS does not rely on a hihj electrical conductivity substrate or admixture to enable the SERS process. The novelty of our method is to create an artificial periodic electron distribution on a surface by illumination with ultraviolet radiation whose photon energy is above the photoelectric work…
The effect of adding 2 at.% W to a model Ni-Al-Cr superalloy on the morphological evolution, spatial correlations and temporal evolution of g'(L12)-precipitates at 1073 K is studied with scanning electron microscopy and atomic force microscopy. Adding W yields a larger microhardness, earlier onset of spheroidal-to-cub…
A systematic study of nine binary and ternary spinel oxides formed from Co, Al, and Fe is presented by means of density functional theory. Analysis of the structural, magnetic, and electronic properties through the series of materials is carried out. Preference for the octahedral spinel sites are found in the order $\…
A systematic microscopic theory of magnetically induced ferroelectricity and lattice modulation is presented for various electron configurations of Mott-insulating transition metal oxides. The origin of polarization is classified as the spin-orbit interaction effective (i) within the magnetic ${t}_{2g}$ orbitals, (ii)…
UNLABELLED: To date, the in vivo imaging of quantum dots (QDs) has been mostly qualitative or semiquantitative. The development of a dual-function PET/near-infrared fluorescence (NIRF) probe can allow for accurate assessment of the pharmacokinetics and tumor-targeting efficacy of QDs. METHODS: A QD with an amine-funct…
Oxidation of graphite produces graphite oxide, which is dispersible in water as individual platelets. After deposition onto Si/SiO2 substrates, chemical reduction produces graphene sheets. Electrical conductivity measurements indicate a 10000-fold increase in conductivity after chemical reduction to graphene. Tapping…
Individual graphene oxide sheets subjected to chemical reduction were electrically characterized as a function of temperature and external electric fields. The fully reduced monolayers exhibited conductivities ranging between 0.05 and 2 S/cm and field effect mobilities of 2-200 cm2/Vs at room temperature. Temperature-…
Structural information on nanometer-sized gold particles has been limited, due in part to the problem of preparing homogeneous material. Here we report the crystallization and x-ray structure determination of a p-mercaptobenzoic acid (p-MBA)-protected gold nanoparticle, which comprises 102 gold atoms and 44 p-MBAs. Th…