Materials Literature
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Nanobinary (Mg−Al) and ternary (Ni−Mg−Al) metal oxy/hydroxides were synthesized by aerogel protocol. The key features of this method are homogenization of metal organic precursors in methanol−toluene mixture, controlled hydrolysis, gelation, hydrothermal treatment, and finally supercritical drying of solvent. The obta…
The optical and structural properties of H or He implanted ZnO were investigated using low temperature photoluminescence (PL) and infrared spectroscopy (IR). H implantation is shown to influence the relative luminescence intensities of the donor bound excitons, enhancing the 3.361 eV peak, and changing the overall int…
The chiral fluorenol mesogen ( R )-2-(1-octyloxy)-7-((4-undecyloxybenzoyl)oxy)fluoren-9-ol (( R )- 3 ) was synthesized using a combined directed metalation-cross coupling strategy. The SmC* liquid crystal phase formed by the fluorenol mesogen is more stable and has a wider temperature range than that formed by the flu…
Oxygen chemisorption at metal surfaces has been shown through a combination of scanning tunnelling microscopy and photoelectron spectroscopy to involve transient states that provide low energy pathways for a wide range of surface reactions including the catalytic oxidation of ammonia and hydrocarbons. The kinetically…
Ceria-based ternary oxides are widely used in many areas of chemistry, physics, and materials science. Synchrotron-based time-resolved x-ray diffraction, x-ray absorption near-edge spectroscopy (XANES), Raman spectroscopy, and density-functional calculations were used to study the structural and electronic properties…
X-ray structure determinations of two different single crystals of octamethylferrocenium tetrafluoroborate (OMFc(+)BF(4)(-)) revealed conformational polymorphism with ligand twist angles of 180 degrees and 108 degrees , respectively. Their concomitant occurrence could be explained by the small lattice energy differenc…
Abstract 12‐Hydroxydodecanoate (HD) anions were intercalated, via an ion‐exchange procedure, onto a Mg/Al hydrotalcite‐like compound with the formula [Mg 0.65 Al 0.35 (OH) 2 ](NO 3 ) 0.35 ·0.56H 2 O. The obtained intercalate, characterized by chemical and thermal analyses, X‐ray powder diffraction, and Fourier transfo…
Two new types of silsesquioxanes, (HSiO 3/2 ) x [( t BuO)SiO 3/2 ] z or T H Q and (HSiO 3/2 ) x (RSiO 3/2 ) y [( t BuO)SiO 3/2 ] z or T H T R Q (R = octadecyl), were synthesized and studied as low- k dielectric materials for electronic applications. The materials were prepared by cohydrolysis and condensation of alkox…
The breakdown of the Schmid law in bcc metals has been known for a long time. The asymmetry of shearing in the slip direction 〈111〉 in the positive and negative sense, respectively, commonly identified with the twinning-antitwinning asymmetry, is undoubtedly one of the reasons. However, effect of stress components oth…
The present study has been aimed to combine the advantages of the two single-phase materials, Al2O3 and ZrO2 while avoiding their disadvantages, by producing a mixed ceramic. Within a study of an ATZ ceramic we tested the influence of aging by a hydrothermal treatment on the strength, phase composition and surface pro…
We report optical emission of SiC nanocrystallite films, which clearly shows the quantum confinement effect. Bulk polycrystalline 3C-SiC was first electrochemically etched and then the fabricated porous silicon carbide was ultrasonically treated in water or toluene suspension to disperse into colloidal nanoparticles.…
Large area highly uniform and ordered polypyrrole nanowire and nanotubearrays were fabricated by chemical oxidation polymerization with the help of a porousanodic aluminium oxide (AAO) template. Under 0.2 moL/L pyrrole (H2O) and 0.2 moL/LFeCl3 (H2O) pattern, polypyrrole nanowire arrays were obtained after 2.0 hourspol…
The occupancy of C-2 and S-6 sites by Eu3+, ions in nanocrystalline powders and microcrystalline ceramics of Lu2O3 prepared from these powders was studied by Mossbauer spectroscopy. It was proved that in nanopowders prepared by vigorous combustion syntheses the occupancy of the C-2 and S-6 sites by Eu3+, is almost ran…
We report on anisotropic magnetoresistance (AMR) and Hall effect measurements along the and [001] directions in a (110)-oriented La 2/3 Ca 1/3 MnO 3 thin film. While the electrical resistivity and the ordinary Hall coefficient are smaller for I along [001], evidencing some anisotropy of the Fermi surface, both the AMR…
Abstract We discuss the effects of the melt compounding variables, matrix molecular weight and organoclay content on the X‐ray diffraction (XRD) and mechanical properties of polystyrene (PS)/organoclay nanocomposites (PNC) prepared in a twin‐screw extruder. An increase of residence time reduced the height of the first…
Zn 0.9 Mg 0.1 O ∕ Zn O p-n junctions were grown by pulsed laser deposition at ⩽500°C on bulk n-type, (100), nonpolar, a-plane ZnO substrates. No postgrowth annealing was performed, with the P-doped ZnMgO showing p-type conductivity (hole density ∼1016cm−3, mobility ∼6cm2V−1s−1) in the as-grown state. Front-to-back p-n…
Three-dimensional model binary glasses produced by quenching from a range of liquid temperatures were tested in shear over a range of strain rates using molecular-dynamics techniques. Tests were performed under constant volume and constant pressure constraints. The simulations revealed a systematic change in short-ran…
ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication to the EditorNEXTFacile Control of Chiral Packing in Poly(p-phenylenevinylene) Spin-Cast FilmsAndrew Satrijo and Timothy M. SwagerView Author Information Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139…
Nanocrystalline apatites exhibit a very fragile structured hydrated surface layer which is only observed in aqueous media. This surface layer contains mobile ionic species which can be easily exchanged with ions from the surrounding fluids. Although the precise structure of this surface layer is still unknown, it pres…
Cadmium sulfide and cadmium selenide/cadmium sulfide core/shell nanoparticles stabilized with poly(cysteine acrylamide) have been bound to polystyrene (PS) latexes by three methods. First, anionic 5 nm diameter CdS particles were electrostatically attached to 130 nm surfactant-free cationic PS latexes to form stable d…