Materials Literature
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We report on the conductance of multiwalled carbon nanotubes as a function of voltage and temperature between room temperature and 4.2 K. The data show a monotonic decrease in conductance as the temperature is lowered. At temperatures below about 20 K, a nonlinearity develops in the $V(I)$ data, corresponding to a pro…
The electrical resistivity \ensuremath{\rho} and the thermopower \ensuremath{\alpha} of the transition-metal pentatelluride system ${\mathrm{Hf}}_{1\ensuremath{-}X}{\mathrm{Zr}}_{X}{\mathrm{Te}}_{5\ensuremath{-}Y}{\mathrm{Sb}}_{Y}$ have been measured over a broad range of temperature, $10\mathrm{K}<T<300\mathrm{…
Annealing atmosphere effects on domain structures and electrical properties of Pb[(Zn1/3Nb2/3)0.5(Zr0.47Ti0.53)0.5]O3 (PZN–PZT) ferroelectric materials were investigated. The PZN–PZT specimens were annealed in argon, air, oxygen, and PbZrO3 atmospheres after being sintered at 1100 °C in air. The as-sintered specimens…
We have examined the valence-electron emission from Cu, Ge, GaAs, InP, and NiO single crystals under the condition of strong x-ray Bragg reflection; i.e., in the presence of the spatially modulated x-ray standing-wave interference field that is produced by the superposition of the incident and reflected x-ray beams. T…
Abstract The chitosan hydroxyl azacrown ether was synthesized by reaction of hydroxyl azacrown ether with epoxy‐activated chitosan. The C 2 amino group in chitosan was protected from the reaction between benzaldehyde and chitosan to form N ‐benzylidene chitosan. After reaction with epichlorohydrin and azacrown ether,…
The injection of holes from a Ag electrode into poly-dialkoxy-p-phenylene vinylene is investigated by measuring the current–voltage characteristics as a function of temperature. For this model system, the hole injection is hindered by a contact energy barrier of about 1.0 eV. The observed temperature dependence of the…
A low-field theory for paramagnetic relaxation enhancement (PRE), appropriate for the outer-sphere relaxation, is presented for the electron spin quantum number S = 1, 3/2, 2, 5/2, 3 and 7/2. The theory is used to calculate the PRE at low magnetic field, as a function of the translational diffusion coefficient, for va…
Abstract Polyacrylic acid (PAA) blending with lactose or polyol, a lactose derivative, is investigated by Fourier transform infrared, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and stress–strain tests. The IR spectra of PAA/lactose blends exist shifting around 1700 cm and 3400 cm −1 , i…
Optical properties of SrBi2Ta2O9 (SBT) ferroelectric thin films were investigated by spectroscopic ellipsometry at room temperature in the 1.5–5.5 eV spectral range. The films were grown on platinized silicon (Pt/Ti/SiO2/Si) with a Bi/Sr ratio (x) range from 1.2 to 2.8 by pulsed-laser deposition. The measured pseudodi…
This letter describes the promising technique of micromachining using the properties of electrochemical etching of (100)-oriented n-type silicon in a hydrofluoric acid electrolyte. The technique is based on electropolishing of a wafer except for areas where vertical structures are needed and does not require a periodi…
Abstract In this work, the influence of temperature, molecular weight ( M̄ n ), and molecular weight dispersity (MWD) on the surface tension of polystyrene (PS) was evaluated using the pendant drop method. The influence of temperature on the surface tension of isotatic polypropylene (i‐PP) and of linear low‐density po…
We have developed an ultrafast, light-scattering spectroscopic system combining a conventional microscope with a pump–probe setup. We successfully measured the surface plasmon resonance band for the individual gold particles with a mean radius of 40 nm. The results on the pump–probe experiment demonstrate that both th…
The same method used to determine ${\ensuremath{\sigma}}^{*}$ excitations in the x-ray-absorption spectra of organic molecules is applied to analyze the structure of the ${\ensuremath{\sigma}}^{*}$ band in the x-ray absorption spectra of amorphous carbon $(a\ensuremath{-}\mathrm{C})$ films. The analysis assumes that o…
(55)Mn NMR spectra of several ferromagnetic manganites, including La(0.7)Ca(0.3)MnO(3) and La(0.7)Sr(0.3) MnO(3), were measured as a function of temperature. A thorough analysis of the spin-spin relaxation and the NMR line shape revealed that in these compounds two different ferromagnetic phases coexist below T(C) in…
Abstract The influence of the carbon black content on the mechanical and electrical properties of polypropylene/carbon black composites prepared by different processing procedures was investigated. The formation of a continuous conducting network in the insulating matrix and, consequently, the percolation threshold de…
LDH-F hydrotalcite catalysts are found to be an efficient, environmentally attractive and selective solid base catalysts for 1,4-Michael addition and also for simple synthesis of α,β-unsaturated esters and nitriles by Knoevenagel condensation. The catalyst displayed unprecedented catalytic activity both in Knoevenagel…
Templated ZnO thin-film growth from the vapor phase is achieved on docosyltrichloro- silane-patterned Si substrates using atomic layer epitaxy (ALE) combined with soft lithography. Patterned hydrophobic self-assembled monolayers (SAMs) are first transferred to single-crystal Si surfaces by hot microcontact printing. U…
Abstract Bave was acquired by the forced silking of three Bombyx mori silkworms, and its tensile properties were characterized. The material collected from any given silkworm yielded reproducible force‐displacement plots, which were qualitatively similar to the plots obtained from silk collected from the other silkwor…
Nanostructured copper was produced by deformation under large sliding loads. In the near surface layers, 10 nm scale microstructures form and coarsen with increasing depth from the surface. The graded structure enables characterization of the structural scale over several orders of magnitude. Analysis reveals that uni…
Advanced algorithms are necessary to obtain faster-than-real-time dynamic simulations in a number of different physical problems that are characterized by widely disparate time scales. Recent advanced dynamic Monte Carlo algorithms that preserve the dynamics of the model are described. These include the $n$-fold way a…