Materials Literature
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This study of the one dimensional Su-Schrieffer-Heeger model in a weak coupling perturbative regime points out the effective mass behavior as a function of the adiabatic parameter $ω_π/J$, $ω_π$ is the zone boundary phonon energy and $J$ is the electron band hopping integral. Computation of low order diagrams shows th…
We present a study of the one dimensional Su-Schrieffer-Heeger model Hamiltonian by a diagrammatic perturbative method in the weak electron-phonon coupling regime. Exact computation of both the charge carrier effective mass and the electron spectral function shows that electrons are good quasiparticles in the adiabati…
Tight binding molecular dynamics simulations, with a non orthogonal basis set, are performed to study the fragmentation of carbon fullerenes doped with up to six silicon atoms. Both substitutional and adsorbed cases are considered. The fragmentation process is simulated starting from the equilibrium configuration in e…
Magnetization, susceptibility, and specific heat measurements were made on a single crystal of ${\mathrm{La}}_{0.75}{\mathrm{Sr}}_{0.25}{\mathrm{MnO}}_{3}.$ The ferromagnetic-to-paramagnetic phase transition was found at 346 K and four critical exponents were measured as: $\ensuremath{\alpha}=0.05\ifmmode\pm\else\text…
A simple method to disperse individual single walled carbon nanotubes (SWCNT ) on an atomically flat substrate is presented. Proper tuning of ac modes of atomic force microscopes(AFM) is discussed. This is needed to discriminate between individual nanotubes and very small bundles. The distribution of lengths of the na…
A simple method was discovered to prepare tungsten oxide nanowires directly from tungsten metal. The structure and composition of the nanowires were characterized by high resolution tunneling electron microscopy (HRTEM) and energy dispersive X-ray scattering (EDX), respectively. The growth mechanism and potential appl…
Abstract Poly(tetrafluoroethylene) (PTFE) powders were mounted on an electroless nickel/phosphorous (Ni/P) film on the surface of a carbon fiber by an electroless codeposition method. This type of carbon fiber filler, denoted FENCF, was then compounded with acrylonitrile–butadiene–styrene (ABS) for use in electromagne…
The reaction of [(TrPP)FeII(py)2] (TrPP = dianion of 5,10,15-triphenylporphyrin) with hydrogen peroxide results in oxygenation of the (porphyrin)iron and the formation of (10,15,20-triphenyl-5-oxophlorin)iron [(5-O-TrPP)Fe(py)2]. Coupled oxidation of [(TrPP)FeIIICl] in the presence of ascorbic acid and potassium cyani…
Experimental measurements of the energy distribution of the backscattered electrons (BSE) in a SEM were made with an improved electrostatic toroidal spectrometer and Monte Carlo simulations were used to calculate these BSE spectra. Pure materials, thin films on a substrate and multilayered `sandwich'-structures were u…
A modification of the magnetic structure was observed in hexagonal antiferromagnetic ${\mathrm{ScMnO}}_{3}$ upon transmission of an intense near-infrared light pulse. Photomagnetic effects lead to a rotation of the magnetic moments inside the basal plane of the ${\mathrm{Mn}}^{3+}$ lattice for which the presence of a…
ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication to the EditorNEXTSynthesis and Efficient Purification of Cyclic Poly(dimethylsiloxane)Bryan M. White, W. Philip Watson, Erin E. Barthelme, and Haskell W. BeckhamView Author Information School of Chemistry and Biochemistry and School of Textile and F…
Different aspects related to the separation of enantiomers of mandelic acid by direct crystallization are explored. Solubility, nucleation, and solid-phase transformation in aqueous solutions are investigated. Results show that a metastable conglomerate can be formed for a substance known to appear as a racemic compou…
Continuous series of solid solutions of strontium and lead apatite Sr(10−x)Pbx(PO4)6(OH)2 (0 ⩽ x ⩽ 10), synthesized in aqueous media have been investigated by X-ray powder-pattern fitting, 31P MAS NMR and IR spectroscopy. The lattice dimensions and the IR frequencies of the solid solutions vary linearly with the atom%…
Abstract Strain gradient implies an important characteristic in localized damage deformation, which can be observed in the softening state of brittle materials, and strain gradients constitute the basic behaviours of localization failure area of the materials. The most important point in strain gradient is its damagin…
The relative stability of the ferroelectric rhombohedral ${(F}_{R})$ and antiferroelectric orthorhombic ${(A}_{O})$ phases of $({\mathrm{Pb}}_{1\ensuremath{-}x}{\mathrm{Ba}}_{x}){\mathrm{ZrO}}_{3}$ has been investigated as a function of ${\mathrm{Ba}}^{2+}$ concentration (x) using phenomenological theory consideration…
Abstract The mechanical properties of blends of polyamide6 (PA6) and ethylene vinyl acetate (EVA) at a blending composition of 0–50 wt % EVA were studied. The notched Izod impact strength of PA6 increased with the incorporation of EVA, the increase being more than 100% compared to PA6 at 10% EVA. The tensile strength…
We have prepared silver selenide nanowires by a novel synthesis technique. The nanowires were produced through template directed synthesis, in which we used a porous alumina membrane as the template. Silver was deposited on one surface and in the pores close to that surface of the template, followed by electro-deposit…
Four new mononuclear complexes of formula Cd(PN)(4)(NCS)(2) (A), Cd(PNN)(4)(N(3))(2) (B), Zn(PNN)(4)(N(3))(2) (C), and Zn(PNN)(2)(NCS)(2) (D), where PNN stands for 2-(4-pyridyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide and PN for 2-(4-pyridyl)-4,4,5,5-tetramethylimidazoline-1-oxyl, were synthesized and structural…
Abstract Chemical cellulose (dissolving pulp) was prepared from ascidian tunic by modified paper‐pulp process (prehydrolysis with acidic aqueous solution of H 2 SO 4 , digestion with alkali aqueous solution of NaOH/Na 2 S, bleaching with aqueous NaOCl solution, and washing with acetone/water). The α‐ cellulose content…
Resonant Raman spectra of individual single-walled carbon nanotubes (SWNTs) and thin SWNT bundles have been acquired by scanning confocal Raman microscopy. The position of several Raman modes was followed in dependence of the diameter-dependent radial-breathing modes (RBMs) and the excitation energy. For semiconductin…