Materials Literature
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Under well-controlled conditions, different polypyrrole variants can be galvanostatically prepared in acetonitrile + 1% H 2 O by changing the current density. At current densities down to 0.25 mA/cm 2, PPy(I) is electrosynthesized; at lower current densities, a mixture of PPy(I) and PPy(II) is generated. In the presen…
A low-temperature solution-based synthetic method was developed for the large-scale synthesis of one-dimensional nanostructures of alkali titanates. Two kinds of highly pure ribbonlike titanates were synthesized successfully in gram quantities without introducing any templates or catalysts. The structure and compositi…
A non-layer-shrinkage fluorinated ferroelectric liquid crystal compound, 8422[2F3], has been characterized by means of optical, x-ray, and calorimetric methods. The orientational distribution within macroscopic volumes, determined through wide-angle x-ray scattering and birefringence measurements, was found to be iden…
The synthesis and photophysical characterization of a generation 1 dendrimer containing four coumarin 2 laser dyes at the periphery and a perylenebis(dicarboximide) derivative at the core are described. It was found that 99% of the UV light absorbed by the peripheral coumarin 2 donor chromophores is transferred throug…
Time-resolved Faraday rotation is used to study both transverse and longitudinal spin relaxation in chemically synthesized CdSe nanocrystals (NC's) 22--80 \AA{} in diameter. The precession of optically injected spins in a transverse magnetic field occurs at distinct frequencies whose assignment to electron and exciton…
The advent of synchrotron sources has led to an increasing availability of high resolution Compton Profiles J(pz) and a consequent renewed interest in the reconstruction of the corresponding full momentum densities rho(p). We present results of applying a new method in which the radial parts of rho(p) and the measured…
Superperiodic patterns with a long distance in a nanographene sheet observed by STM are discussed in terms of the interference of electronic wave functions. The period and the amplitude of the oscillations decrease spatially in one direction. We explain the superperiodic patterns with a static linear potential theoret…
Molecular dynamics simulations are used to examine how thermal transport is affected by the presence of one or more interfaces. Parameters such as film thickness, the ratio of respective material composition, the number of interfaces per unit length, and lattice strain are considered. Results indicate that for simple…
We study phases and phase transitions that can take place in the recently discovered bow-shaped or bent-core liquid-crystal molecules. We show that to completely characterize phases exhibited by such bent-core molecules a third-rank tensor T(ijk) order parameter is necessary in addition to the vector and the nematic (…
Rules are given for determining special directions in the Brillouin zone which optimize the descrip-tion of various physical quantities with Gamma1 type symmetry. We consider the cubic, hexagonal, tetragonal and trigonal (e.g. Bi) lattice. These rules allow us to construct, in all of momentum space, quantities which h…
We report structural and magnetic properties of multilayers composed of thin layers of the half metallic ferromagnetic Heusler compound Co2MnGe and layers of Au, Cr and the Heusler compound Cu2MnAl. The hysteresis loops measured at low temperatures reveal the existence of an exchange bias field HEB in all of these mul…
We have investigated electronic structures of La$_3$S$_4$ and Ce$_3$S$_4$ using the LSDA and LSDA+$U$ methods. Calculated density of states (DOS) are compared with the experimental DOS obtained by the valence band photoemission spectroscopy. The DOS at $E_{\rm{F}}$ indicates the 5$d$ character in La$_3$S$_4$ and 4$f$…
The effects of $n$-type carrier doping by Li intercalation on magnetism in undoped and Co-doped anatase TiO$_2$ are investigated. We have found that doped $n$-type carriers in TiO$_2$ are localized mainly at Ti sites near the intercalated Li. With increasing the intercalation, local spins are realized at Ti. In the ca…
The search for other superconductors in the MgB2 class currently is focussed on Li{1-x}BC, which when hole-doped (concentration x) should be a metal with the potential to be a better superconductor than MgB2. Here we present the calculated phonon spectrum of the parent semiconductor LiBC. The calculated Raman-active m…
Abstract The strength properties of polypropylene fibers were enhanced with single‐wall carbon nanotubes (SWNTs). Solvent processing was used to disperse SWNTs in a commodity polypropylene. After the solvent was removed, the solid polymer was melt‐spun and postdrawn into fibers of unusual strength. For a 1‐wt % loadin…
Cell targeting with magnetic nanoparticles raises a growing interest in the fields of both cellular biology and medical imaging. We have investigated the nonspecific interactions of superparamagnetic negatively charged iron oxide nanoparticles with HeLa tumor cells and mouse RAW macrophages, qualitatively by electron…
We report on structural, magnetic, and electrical properties of Sr-doped ${\mathrm{LaMnO}}_{3}$ single crystals for doping levels $0.4<~x<~0.85.$ The complex structural and magnetic phase diagram can only be explained assuming significant contributions from the orbital degrees of freedom. Close to $x=0.6$ a ferr…
By decomposing Zn(OH) 4 2 - or Zn(NH 3 ) 4 2+ precursor in various solvents at suitable reaction conditions, zinc oxide with a diversity of well-defined morphologies was synthesized. Flowerlike ZnO built up by nanorods was obtained by treating Zn(OH) 4 2 - precursor in water at 180 °C for 13 h. Whereas a replacement o…
The present work reports electrochemical synthesis of a semi-IPN (s-IPN) following electropolymerization of pyrrole from an aqueous medium within a crosslinked network of PVA. This combination resulted in a set of free standing and flexible films having high electrical conductivity and good environmental stability. Pr…
The photophysics of PAMAM (poly-amidoamine) based dendrimers (generations G0-G4) modified with (4, 8, 16, 32, and 64) pendant-[Ru(tpy) 2 ] +2 (tpy is 2,2‘:6‘,2‘ ‘-terpyridine) and [Ru(bpy) 3 ] +2 (bpy is 2,2‘-bipyridine) chromophores have been studied in both fluid solution at 298 K and frozen glasses, at 77 K. The ab…