Materials Literature
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We have applied the FTIR-luminescence/FT-Raman technique to map the near-infrared photoluminescence?(PL) of water?surfactant dispersions of single-walled carbon nanotubes (SWNTs) in broad excitation (250?1500?nm) and emission (800?1700?nm) ranges. The excitation wavelength was scanned by using the monochromatized ligh…
Effects of disorder on the two competing phases, i.e., the ferromagnetic metal and the commensurate charge/lattice ordered insulator, are studied by Monte Carlo simulation. The disorder suppresses the charge/lattice ordering more strongly than the ferromagnetic order, driving the commensurate insulator to the ferromag…
Chemical characterization of cellulose derivatives is of high importance as it provides information about the often inhomogeneous substitution that may seriously affect the properties of these polymers in various applications. A detailed mapping of the chemical structure of these derivatives requires several advanced…
The equilibrium polymerization of sulfur is investigated by Monte Carlo simulations. The potential energy model is based on density functional results for the cohesive energy, structural, and vibrational properties as well as reactivity of sulfur rings and chains [Part I, J. Chem. Phys. 118, 9257 (2003)]. Liquid sampl…
The study of polarization reversal in (Pb,La)(Zr,Ti)O3 thin films reveals a drastic difference between the switching kinetics observed at RT and at low temperature of 40 K. In particular, at 40 K, the switching kinetics in studied films is similar to that observed in ferroelectric single crystals. Additionally, the fi…
Well‐aligned silica nanotubes with lengths up to 0.9–1.0 mm have been prepared via a vapor–liquid–solid process. The nanotubes are either partially filled with indium or hollow (see Figure). The thermal expansion behavior of a liquid indium column inside a silica nanotube, a prospective novel inorganic nanotube‐based…
We study the kinetics of the isotropic-smectic phase transition in a colloidal rod/polymer mixture by visualizing individual smectic layers. First, we show that the bulk isotropic-smectic phase transition is preceded by a surface freezing transition in which a quasi-two-dimensional smectic phase wets the isotropic-nem…
We have demonstrated narrow-band visible light emission from size selected silicon nanoparticles (np-Si), with a wavelength controlled by size tuning. The np-Si were synthesized by pulsed-laser ablation of a silicon single-crystal target in high-purity He background gas. A postannealing process improved morphology and…
The growth of CuCrO 2 films on glass substrate by LP‐MOCVD is reported . Unlike nearly all transparent conducting oxides which exhibit only n‐type conductivity, CuCrO 2 crystalline thin films deposited from Cu(acac) 2 and Cr(acac) 3 precursors exhibit positive Hall co‐efficient with the highest carrier Hall mobility r…
Abstract The 1,3,5‐triazine derivatives 1 − 4 having styryl or higher oligo(phenylenevinylene) chains in the 2‐, 4‐, and 6‐positions represent star‐shaped push‐pull compounds. Alkoxy or dimethylamino groups on the peripheral benzene rings, which act as electron donors, and the central 1,3,5‐triazine ring, which acts a…
A structuring method capable of producing uniform, large-area cone arrays of diamond films was developed. The technique employs bias-assisted reactive ion etching and is applicable to any structure of diamond films ranging from microcrystalline to nanocrystalline. Variation of the etching conditions enables control of…
We present a novel family of "potentially antiaromatic" alkyl-substituted p-benzoquinonediimine pH-dependent chromophores. It appears from the structural data that these overall 12 pi-electron molecules should be better considered as constituted by two chemically connected but electronically not conjugated 6 pi-electr…
Remarkable doughnut‐shaped micrometer‐sized aragonite particles with mesoporous sponge‐like interiors (see Figure) are spontaneously assembled in water‐in‐oil microemulsions. The structures consist of an interlinked network of complex nanofilaments that arise from the surfactant‐mediated mesoscale transformation and c…
The glass transition temperature Tg of polystyrene spheres in aqueous suspension was investigated by differential scanning calorimetry. Spheres with diameters of 42–548 nm show an unambiguous glass transition very near the Tg of bulk polystyrene. The magnitude of the observed heat capacity jump ΔCp at the transition d…
Optical filters containing resonant waveguide gratings are designed and fabricated using low-loss, robust materials. The double-layer filters contain a silicon dioxide diffractive element on a hafnium dioxide waveguide deposited on a fused silica substrate. Noise-pattern formation is minimized by use of an antireflect…
The polarization reversal in single-crystalline ferroelectric films has been investigated experimentally and theoretically. The hysteresis loops were measured for Pb(Zr0.52Ti0.48)O3 films with thicknesses ranging from 8 to 250 nm. These films were grown epitaxially on SrRuO3 bottom electrodes deposited on SrTiO3 subst…
Layer-by-layer (LbL) assembly has been utilized to fabricate an ultrathin film of polyelectrolytes. The architecture was composed of chitosan and organophosphorus hydrolase polycations along with thioglycolic acid-capped CdSe quantum dots (QDs) as the polyanion. The topography of the films was studied using epifluores…
Thermal decomposition of labile poly(acrylic acid) (PAAc) side chains grafted onto fluorinated polyimide backbones (see Figure) is used to prepare nanoporous ultra‐low‐κ fluorinated polyimide films. The dielectric constant of the nanoporous fluorinated polyimide film can be varied by altering the graft concentration o…
Ultrathin Fe nanowire (about 5 nm in diameter) arrays have been fabricated by electrodeposition using anodic porous alumina templates. These ultrathin nanowires exhibited uniaxial anisotropy and a quite large coercivity (4190 Oe) at 5 K. In addition, the field needed to saturate the magnetization, when the field was a…
We report here the first electrochemical pathway to prepare Au-containing nanocomplexes with the mean diameter of 2 nm in 0.1 N KCl aqueous solutions without addition of any stabilizer. Encouragingly, polypyrrole- (PPy-) coated gold nanocomposites with a core−shell structure and a diameter smaller than 8 nm can be pre…