Materials Literature
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[Ni4L3(H2O)2](ClO4)2.2H2O 1, the first tetranuclear NiII cluster showing triangle planar geometry, formed with a new carboxylic-functionalized 1,5-diazacyclooctane bridging ligand has been presented; the global magnetic coupling is ferromagnetic and anisotropic calculations have been made.
Abstract Poly(ethylene oxide/polylactide/poly(ethylene oxide) (PEO/PL/PEO) triblock copolymers, in which each block is connected by an ester bond, were synthesized by a coupling reaction between PL and PEO. Hydroxyl‐terminated PLs with various molecular weights were synthesized and used as hard segments. Hydroxyl‐term…
A stochastic dislocation dynamics (SDD) model is developed to investigate dislocation glide through dispersed obstacles. The model accounts for: 1) the dynamics of the flight process between successive meta-stable dislocations under various drag mechanism using discrete dislocation dynamics, and 2) thermal activation…
We analyze simple shear and torsion of single crystal copper by employing experiments, molecular dynamics simulations, and finite element simulations in order to focus on the kinematic responses and the apparent yield strengths at different length scales of the specimens. In order to compare torsion with simple shear,…
Measurements of the infrared phosphorescence of singlet molecular oxygen (1O2) at 1270 nm have been used to demonstrate the formation of 1O2 by the Radziszewski reaction between acetonitrile and hydrogen peroxide. The kinetics of the Radziszewski reaction either alone or in the presence of ketones have been studied by…
The position of the molecular orbitals of polyaniline, relative to the Fermi level, shifts with the doping of polyaniline by both charge donor and charge acceptor species. Sodium as an electron donor, when added to the polyaniline system, results in an increase in electron population in the polyaniline bands but a dec…
Abstract The dynamic mechanical behavior of uncrosslinked (thermoplastic) and crosslinked (thermosetting) acrylonitrile butadiene rubber/poly(ethylene‐ co ‐vinyl acetate) (NBR/EVA) blends was studied with reference to the effect of blend ratio, crosslinking systems, frequency, and temperature. Different crosslinked sy…
Abstract Correlation between the morphology and the impact toughness was studied for ternary‐phase polypropylene (PP)/glass bead (GB)/ethylene‐propylene rubber (EPR) composites containing 5–40 vol % of rigid filler at a fixed volume fraction ratio EPR/GB equal to 0.33. The three following types of phase morphology wer…
The crystalline symmetry of the solid solution formed by a relaxor and a ferroelectric material with formula: (1−x)Pb(Fe2/3W1/3)O3–xPbTiO3, with various x was investigated, at T=300 K. A continuous change from pseudocubic to tetragonal symmetry, with cell parameters dependent on the PbTiO3 amount, was found. In a larg…
A phenomenological, polycrystalline version of a nonlocal crystal plasticity model is formulated. The presence of geometrically necessary dislocations (GNDs) at, or near, grain boundaries is modeled as elastic lattice curvature through a curl of the elastic part of the deformation gradient. This spatial gradient of an…
Macroporous SiC with a highly ordered pore array was prepared for the first time using low molecular weight SiC preceramic polymers such as polymethylsilane or polycarbosilane by utilizing sacrificial colloidal silica crystalline arrays, as a template which were subsequently etched off after pyrolysis in an argon atmo…
Up to now, electric-field-induced nonlinear conduction in the ${\mathrm{Pr}}_{1\ensuremath{-}x}{\mathrm{Ca}}_{x}{\mathrm{MnO}}_{3}$ system (PCMO) has been ascribed to a current-induced destabilization of the charge ordered phase. However, for $x<~0.25,$ a ferromagnetic insulator state is observed, and charge orderi…
Er-doped tin–silicate glass–ceramic composites were synthesized from Si, Er and Sn molecular precursors by following a sol–gel method. Optical spectroscopy and electron microscopy showed that the resulting material is composed of an amorphous silica network that encloses submicrometric SnO2 crystalline clusters. Analy…
The purpose of this two-part article, is first to give an update of recent developments of gradient plasticity as this was advanced by Aifantis and co-workers in the early eighties to address dislocation patterning and shear band problems, and then to elaborate on two specific issues of current interest: size effects…
Abstract Two new sequential poly(ester amide)s (PEAs) derived from 1,4‐butanediol, sebacic acid, and L ‐alanine (PABA8) or glycine (PGBG8) are prepared and characterized. For comparative purposes the related polyesters (PEs) 4,10 and 6,10 are also studied. The calorimetric analysis shows that the inclusion of amino ac…
p -type conducting films of α-BuCu2S2 have been deposited onto glass and KBr substrates, yielding a conductivity of 17 S/cm and a Hall mobility of 3.5 cm2/V s. For a 430-nm-thick film, the optical transparency approaches 90% in the visible portion of the spectrum at 650 nm, and a transparency of 40% extends throughout…
We fabricated an all-perovskite oxide p-n junction comprised of hole-doped (p-) manganite La0.9Ba0.1MnO3 and electron-doped (n-) titanate Sr0.99La0.01TiO3 films. The junction showed good rectifying properties at both room temperature and low temperature in a simple structure without inserting an insulating layer. By o…
Oxide thin films are usually grown on substrates which offer the smallest mismatch with the desired structure of the film. The choice of high-quality substrates with suitable lattice constants is unfortunately very limited. Coherently grown films are therefore always under tensile or compressive in-plane strain. We re…
Since the discovery of Fe–Ni alloys showing low thermal expansion (LTE) in 1896, many Invar alloys have been developed based on magnetovolume effect where negative thermal expansion is induced by magnetic transformation. Herein, we show that the control of stress-induced martensitic transformation due to cold working…
The electron energy-loss near-edge structure (ELNES) at the O K edge has been studied in yttria-stabilized zirconia (YSZ). The electronic structure of YSZ for compositions between 3 and 15 mol % ${\mathrm{Y}}_{2}{\mathrm{O}}_{3}$ has been computed using a pseudopotential-based technique to calculate the local relaxati…