Materials Literature
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The rate of electron tunneling in molecular donor-bridge-acceptor (D-B-A) systems is determined both by the tunneling barrier width and height, that is, both by the distance between the donor and acceptor as well as by the energy gap between the donor and bridge moieties. These factors are therefore important to contr…
The recently developed technique of reductive amination, followed by gold labeling, was applied to visualize the reducing ends of cellulose microcrystals from cellulose I, cellulose II, and cellulose III(I). In these crystals, which were also characterized by electron diffraction, the labeling proved that the chains w…
We compare two approaches to the atomic, electronic, and magnetic structures of $\mathrm{La}\mathrm{Mn}{\mathrm{O}}_{3}$ bulk and the (001), (110) surfaces---hybrid B3PW with optimized LCAO basis set (CRYSTAL-2003 code) and GGA-PW91 with plane-wave basis set (VASP 4.6 code). Combining our calculations with those avail…
Magnetic and half-metallic properties of ${\mathrm{Co}}_{2}({\mathrm{Cr}}_{1\ensuremath{-}x}{\mathrm{Fe}}_{x})\mathrm{Ga}$ Heusler alloys have been investigated. In the entire concentration range, the $L{2}_{1}$-type ordered phase is obtained. The saturation magnetic moment ${M}_{s}$ at $4.2\phantom{\rule{0.3em}{0ex}}…
A novel defect mode is realized in a three-layered structure: a left-handed cholesteric liquid crystal (CLC) layer sandwiched between right-handed CLC films (see Figure). The defect states emerge, and the photonic density of state is resonantly enhanced when the defect mode coincides with the edge mode. The lasing fro…
Singlet excitation energy transfer is governed by two donor-acceptor interactions, the Coulombic and exchange interactions giving rise to the Förster and Dexter mechanisms, respectively, for singlet energy transfer. In transfer between colliding molecules or between a donor (D) and acceptor (A) connected in donor-brid…
A two-step "grafting from" method has been successfully carried out, which is based on the electrografting of polyacrylate chains containing an initiator for the atom transfer radical polymerization (ATRP) of 2-(tert-butylamino)ethyl methacrylate (TBAEMA) or copolymerization of TBAEMA with either monomethyl ether of p…
An approach is demonstrated for growing aligned ZnO nanowire/nanorod arrays following a predesigned pattern and feature with controlled site, shape, distribution, and orientation. The technique relies on an integration of atomic force microscopy (AFM) nanomachining with catalytically activated vapor-liquid-solid (VLS)…
Abstract Amorphous‐made poly( L ‐lactide) [i.e., poly( L ‐lactic acid) (PLLA)], poly( L ‐lactide‐ co ‐ D ‐lactide)[P(LLA‐DLA)](77/23), and P(LLA‐DLA)(50/50) films and PLLA films with different crystallinity ( X c ) values were prepared, and the effects of molecular weight, D ‐lactide unit content (tacticity and optica…
Regular, single-crystalline nanocubes of Prussian blue, Fe 4 [Fe(CN) 6 ] 3, with different sizes were synthesized in large quantities by a direct dissociation of the single-source precursor K 4 Fe(CN) 6 in acidic solution under ultrasonic conditions. The size and size distribution of the cubes strongly depends on the…
The use of porphyrins in fundamental studies and diverse applications requires facile access to ample quantities of material in pure form. The existing conditions for the condensation of a dipyrromethane plus a dipyrromethane−dicarbinol employ 2.5 mM reactants and afford ∼30% yields with no detectable scrambling. Larg…
Synchrotron-based in situ time-resolved x-ray diffraction and x-ray absorption spectroscopies were used to study the behavior of nanostructured {Au+AuO(x)}-CeO(2) catalysts under the water-gas shift (WGS) reaction. At temperatures above 250 degrees C, a complete AuO(x)-->Au transformation was observed with high cataly…
Epitaxial growth of well-aligned tin-doped indium oxide (ITO) nanowire arrays on substrates of (100) yttrium-stabilized zirconia with vertical and inclined orientations is reported. Branched ITO nanowires are grown on (100) ITO nanowire backbones by a second step of Au-catalyzed vapor–liquid–solid growth. The Figure s…
We compare two theoretical approaches to diblock copolymer melts in an external electric field. The first is a relatively simple analytic expansion in the copolymer composition and includes the full electrostatic contribution consistent with that expansion. It is valid close to the order−disorder transition point, the…
One region of the electromagnetic spectrum that is relatively unexploited for materials characterization is the millimeter wave band (frequencies roughly between 40 and 300 GHz). Millimeter wave techniques involve free-space (non-contacting) measurements which have a length scale that makes them ideal for characterizi…
We report structural and electronic characterization of the charge order phase in Bi0.4Ca0.6MnO3 films, in which photoinduced resistivity changes have been observed at temperatures approaching room temperature. In all films, lattice distortions associated with the charge order are observed, and both the wavevectors an…
Ab-initio relativistic dynamical mean-field theory is applied to resolve the long-standing controversy between theory and experiment in the "simple" face-centered cubic phase of plutonium called delta-Pu. In agreement with experiment, neither static nor dynamical magnetic moments are predicted. In addition, the quasip…
The Luttinger surface of an organic metal (TTF-TCNQ), possessing charge order and spin-charge separated band dispersions, is investigated using temperature-dependent angle-resolved photoemission spectroscopy. The Luttinger surface topology, obtained from momentum distribution curves, changes from quasi-2D (dimensional…
We present direct experimental observation of exciton-phonon bound states in the photoluminescence excitation spectra of isolated single-walled carbon nanotubes (SWNT) in aqueous suspension. The photoluminescence excitation spectra from several distinct SWNTs show the presence of at least one sideband related to the t…
Porous materials with controlled pore size and large surface area (see Figure) have been prepared by crosslinking phenolic resin in the presence of a self-assembled block-copolymer template, followed by pyrolysis. Many phenolic hydroxyl groups remain at the matrix and pore walls, which can be used for selective and ef…