Materials Literature
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Colloidal assemblies are used to synthesize FCC cobalt nanoparticles. The particles are coated, extracted from micelles, and characterized by transmission electron microscopy, small angle X-ray scattering, and electron and X-ray diffraction spectroscopy. These cobalt metal particles are stable in air, have a narrow si…
The aging of unstabilized low density polyethylene (LDPE) films and those stabilized with hindered amine light stabilizers (HALS) was studied as a function of the exposure time to thermo-oxidation at 90°C and to natural weathering. The HALS tested was Tinuvin 783 from Ciba-Geigy and added to the polymer in the concent…
The nucleation of small Cu clusters at the surface of SiO 2 has been investigated by means of ab initio quantum chemical calculations using cluster models. The interaction of Cu n clusters ( n =1−5) with a nonbridging oxygen, NBO, a paramagnetic point defect of silica, has been studied by means of DFT calculations usi…
This paper aims to justify, at a microscopic level, the existence of a two-dimensional Bose metal, i.e. a metallic phase made out of Cooper pairs at T=0. To this end, we consider the physics of quantum phase fluctuations in (granular) superconductors in the absence of disorder and emphasise the role of two order param…
The temperature dependence of hydrogen (H) desorption from Si(100) H-terminated surfaces by a scanning tunneling microscope (STM) is reported for negative sample bias. It is found that the STM induced H desorption rate ($R$) decreases several orders of magnitude when the substrate temperature is increased from 300 K t…
Ionomeric polyblends based on zinc salt of maleated EPDM rubber, abbreviated as Zn-mEPDM and zinc salt of poly(ethylene-co-acrylic acid), abbreviated as Zn-PEA in the compositions of 90/10, 80/20, 70/30, 60/40, and 50/50, parts by weight, behave as ionic thermoplastic elastomers. The ionomeric polyblends show synergis…
Although NaOH and NaOD exhibit parallel polymorphism at high temperatures, NaOD exhibits a low-temperature phase transition to a hydrogen-bonded antiferroelectric phase and no comparable transition has been found in NaOH. Measurements of NaOH by dielectric relaxation and adiabatic calorimetry were undertaken to determ…
We have derived a mean field Landau–Ginzburg free energy expression for a ternary symmetric homopolymer/diblock copolymer system from a microscopic Edwards Hamiltonian. We then used the time-dependent Landau–Ginzburg equation to model the time evolution of the order parameters after a critical quench into the region o…
A thin film (<10 nm) of fine metal clusters (silver or gold) with an island form was deposited on a CaF2 salt plate by slow vacuum thermal evaporation. Molecular layers of stearic acid, p-nitrobenzoic acid, and m-nitrobenzoic acid (p- and m-NBA) were prepared on the thin metal film. The system was then examined by inf…
It is known that the forming gas (N2–H2 mixture) annealing process required for microcircuit fabrication results in an unacceptable electrical degradation of SrBi2Ta2O9 (SBT) ferroelectric capacitors due mainly to the interaction of H2 with the ferroelectric layer of the capacitor. We have found a strong relationship…
The interaction of NO with a flat and two stepped Rh(111) surfaces was studied at different temperatures by monitoring in situ the evolution of the O 1s and N 1s spectra during NO exposure using fast high resolution x-ray photoelectron spectroscopy. The O 1s and N 1s intensities and binding energies were used to finge…
We present results of molecular dynamic simulations aimed at examining crack tip dislocation emission in fcc solids. The results are analyzed in terms of recent continuum formulations of this problem. In mode II, Au, Pd, and Pt displayed a new unanticipated mechanism of crack tip dislocation emission involving the cre…
The molecular mobility and hydration properties of model segmented polyurethanes from either poly(propylene glycol) (PPG) or poly(butylene adipate) (PBAD), both of molecular weight 2000 (soft segments), and three different diisocyanates (all-trans 4,4′-dicyclohexylmethane diisocyanate, 100% t,t HMDI; HMDI with 20% of…
Predictions from a recently developed mode coupling theory (MCT) are compared with experimental results for hard-sphere suspensions. A simple scaling of the MCT results leads to good agreement with the data. The scaled MCT predicts that for hard-sphere suspensions the zero-shear limiting viscosity obeys a generalized…
The effect of the matrix material on the magnetostriction of composites containing highly magnetostrictive particles has been studied. Experimental results showed that the elastic modulus of the matrix is an important factor determining the bulk magnetostriction of the composite. For a series of composites with the sa…
We have generated the thin-film ternary composition spread of (Ba1−x−ySrxCay)TiO3 on an equilateral-triangle-shaped LaAlO3 substrate. Compositional variation within the triangle was achieved by a precisely controlled shutter system inside a pulsed laser deposition chamber, which allows the deposition of precursors wit…
Polybutadienes (PBs) of narrow molecular weight distributions with high 1,4-microstructure were synthesized by sec-butyllithium-initiated, living polymerization. The shoulder-like anomalous behavior of the storage modulus G′(ω) in the terminal zone for PBs was studied using size exclusion chromatography (SEC) and rheo…
High-speed spinning of high molecular weight poly(ethylene terephthalate) (PET) having an intrinsic viscosity of 0.98 dL/g was performed at the take-up velocity range of 2.5–5.5 km/min. The structure of the as-spun filaments was analyzed by density, birefringence, WAXS, DSC, boiling water shrinkage, and tensile proper…
Low molecular-weight polylactic acid (PLA) was obtained by direct polycondensation of a mixture of 95% l and 5% d-lactic acid isomers, without catalyst, at 195°C. This polymer was used for the synthesis of microspheres by emulsion–solvent evaporation method. Gel Permeation Chromatography (GPC), X-ray Scattering (XRD),…
The quasicontinuum method is used to simulate three-dimensional Lomer-Cottrell junctions both in the absence and in the presence of an applied stress. The simulations show that this type of junction is destroyed by an unzipping mechanism in which the dislocations that form the junction are gradually pulled apart along…