Materials Literature
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The electronic structure around a single As antisite in GaAs is investigated in bulk and near the surface both in the stable and the metastable atomic configurations. The most characteristic electronic structures of As antisite is the existence of the localized p-orbitals extending from the As antisite. The major comp…
Nitrogen-doped films of ZnO grown by two methods, metalorganic chemical vapor deposition (MOCVD) and reactive sputtering, were studied with x-ray and ultraviolet photoelectron spectroscopy (XPS and UPS). Systematic differences in the N chemical states were observed between films grown by sputtering and MOCVD: only two…
Abstract Amorphous poly(ester‐urethane)s (PEUs) were synthesized by reacting polyoxalate diols (PODs), which are oligoester diols prepared from condensation polymerization of dimethyl oxalate (DMO) and alkane diols, with 4, 4′‐diphenylmethane diisocyanate (MDI) and propylene diamine (PDA), a chain extender. Their stru…
Abstract The initial stages of growth of the lamellar phase in a block copolymer solution were observed with polarizing optical microscopy (POM). Measurements were made on a poly(styrene‐ b ‐isoprene) diblock copolymer with block molecular weights of 15 and 13 kg/mol, respectively, dissolved in dioctyl phthalate with…
We perform field-effect experiments on side-gate devices made of underdoped ${\mathrm{La}}_{0.7}{\mathrm{Sr}}_{0.3}\mathrm{Mn}{\mathrm{O}}_{3\ensuremath{-}\ensuremath{\delta}}$ epitaxial thin films. The resistance modulation is small due to the high carrier concentration in this compound; however, it is significantly…
Abstract Blown films of different types of polyethylenes, such as branched low‐density polyethylene (LDPE) and linear high‐density polyethylene (HDPE), are well known to tear easily along particular directions: along the film bubble's transverse direction for LDPE and along the machine direction (MD) for HDPE. Dependi…
The electroabsorption (EA) spectra of directly meso-meso-linked porphyrin arrays (Zn, n = 1-3) have been investigated by means of the sum-over-states (SOS) approach at the INDO/S-SCI level theory. The experimental EA spectra of Zn (n > or = 2) exhibit an unusual second-derivative line shape at the exciton split low-en…
Abstract The temperature‐dependent behavior of individual components within metallocene‐catalyzed semisyndiotactic polypropylenes (semi‐sPP) with a wide range of stereoregular content (26 to 96% rr ) is studied using Fourier transform infrared (FTIR) spectroscopy and temperature‐modulated differential scanning calorim…
Abstract The influence of the morphology on the mechanical properties of binary styrene–butadiene (SB) triblock copolymer blends of a thermoplastic block copolymer and a thermoplastic elastomer (TPE) with different molecular architectures was studied with bulk samples prepared from toluene. Both block copolymers conta…
Poly(silylene- p -phenylene)s bearing an anthrylethynyl, pyrenylethynyl, or terthienyl group as the pendant were obtained in moderate yield, by substitution reactions of poly[ethoxy(methyl)silylene- p -phenylene] with the corresponding organolithium reagents in THF. The polymers exhibited photoluminescent (PL) propert…
We have developed a thermodynamic model of the catalytic growth of multiwall carbon nanotubes from hydrocarbon precursors at elevated temperature. Using this model we have computed the heat distribution and carbon concentration in the catalyst. Calculations delivered an analytical formula for the growth time and growt…
This paper presents a model for the unsteady species transport for the growth of alloyed semiconductor crystals during the vertical Bridgman-Stockbarger process with a steady axial magnetic field. During growth of alloyed semiconductors such as germanium-silicon (GeSi) and mercury-cadmium-telluride (HgCdTe), the solut…
Based on first-principles calculations, we found that the surface adsorption energetics of Ag on a Si(111) surface can be modified by imposing an external electric field. The preferred adsorption site is found to be field dependent. The most energetically favorable adsorption site of Ag on the Si(111) surface, among a…
Abstract In the present work, the influence of well‐defined simple shear flow histories on the isothermal crystallization of an isotactic polypropylene (i‐PP) has been investigated. At first, the research of the flow conditions in terms of temperature, shear rate ( $\dot{\gamma}$ ) and shear strain (γ) has been perfor…
Abstract Biodegradable poly(butylene succinate) (PBS)/poly(ethylene oxide) (PEO) polymer blend film with compositional gradient in the film thickness direction was prepared using a method of interdiffusion across the interface between the PBS and PEO layers at a temperature above the melting points of both the compone…
An Artificially layered perovskite composed of antiferroelectric PbZrO3 and paraelectric BaZrO3 (BZO) was fabricated on LaNiO3∕Pt∕Ti∕SiO2∕Si substrates at 475 °C by radio-frequency magnetron sputtering. It had an (001)-oriented superlattice structure with an average composition of (Pb0.75Ba0.25)ZrO3 (PBZ). X-ray diffr…
Abstract A novel fluorinated bis(ether amine) monomer, 2,6‐bis(4‐amino‐2‐trifluoromethylphenoxy) naphthalene, was prepared through the nucleophilic aromatic substitution reaction of 2‐chloro‐5‐nitrobenzotrifluoride and 2,6‐dihydroxynaphthalene in the presence of potassium carbonate, followed by catalytic reduction wit…
Electrically commanded surfaces (ECS) is a liquid crystal display concept whereby the switching of the alignment layer, which is driven by an electric field applied across the layer, is further transferred to the bulk liquid crystal material via elastic forces. This work presents the electro-optic response of a sandwi…
Ga 2 O 3 : Dy 3 + and Li+-doped Ga2O3:Dy3+ phosphor films were prepared by a Pechini sol-gel process. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), atomic force microscopy, and photoluminescence (PL) spectra as well as lifetimes were used to characterize the resulting thin films (and powder…
Polymer-coated metal or metal oxide nanoparticles have a variety of uses in industry, biological research, and medicine. Characterization of nanoparticles often includes determination of the dimensions of the electron-dense core by transmission electron microscopy (TEM), with the weight of the core determined from cor…