Materials Literature
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An investigation was conducted on the introduction of amino groups to the surface of activated carbon and the adsorption characteristics of the aminated surface. The organic chemical reactions allowed us to introduce amino groups to the surface of activated carbon without affecting the physical structure of the adsorb…
We have performed $\mathrm{ab}$ $\mathrm{initio}$ pseudopotential electronic structure calculations for various edge geometries of the $(n,n)$ single-wall nanotube with or without applied fields. Among the systems studied, the one with a zigzag edge exposed by a slant cut is found to be the most favorable for emission…
Lead zirconate titanate (PZT) thin films with a Zr/Ti ratio of 52/48 were deposited on platinized silicon substrates by a sol-gel method and crystallized with preferred (111) or (100) orientation. Both the piezoelectric properties (d33) and the field-induced strains of the films with different thickness and preferred…
We present a tight-binding theory to analyze the motion of electrons between carbon nanotubes bundled into a carbon nanotube rope. The theory is developed starting from a description of propagating Bloch waves on ideal tubes, and the effects of intertube motion are treated perturbatively on this basis. Expressions for…
We report on a calibration procedure based on third-harmonic generation, which yields absolute values for ${\ensuremath{\chi}}^{(3)}.$ By calibrating the nonlinear susceptibility ${\ensuremath{\chi}}^{(3)}$ of fused silica against the established, quantum chemically calculated second-order hyperpolarizabilities \ensur…
${\mathrm{Eu}}^{2+}$-doped ZnS nanoparticles with an average size of around 3 nm were prepared, and an emission band around 530 nm was observed. By heating in air at 150 \ifmmode^\circ\else\textdegree\fi{}C, this emission decreased, while the typical sharp line emission of ${\mathrm{Eu}}^{3+}$ increased. This suggests…
We report the effects of potassium doping on the conductance of individual semiconducting single-walled carbon nanotube ropes. We are able to control the level of doping by reversibly intercalating and de-intercalating potassium. Potassium doping changes the carriers in the ropes from holes to electrons. Typical value…
We report a photoluminescence study of silicon nanoclusters produced by laser ablation. It was found that by varying the preparation parameters it was possible to change the mean cluster size in the range 1–5 nm. Within this size variation, the photoluminescence band shifts in a wide spectral region from near ultravio…
Photoluminescence excitation (PLE) spectra, measured at varying temperatures and for different luminescent energies, are applied systematically to the study of defects in $\mathrm{I}a,$ $\mathrm{I}b,$ $\mathrm{II}b,$ and chemical-vapor-deposited (CVD) diamond. It is shown that the green luminescent band in CVD diamond…
We present a detailed quantitative comparison of double-exchange models to experimental data on the colossal magnetoresistance manganese perovskites. Our results settle a controversy by showing that physics beyond double-exchange is important even in ${\mathrm{La}}_{0.7}{\mathrm{Sr}}_{0.3}{\mathrm{MnO}}_{3},$ which ha…
We introduce a continuous damage fiber bundle model that gives rise to macroscopic plasticity and compare its behavior with that of dry fiber bundles. Several interesting constitutive behaviors are found in this model depending on the value of the damage parameter and on the form of the disorder distribution. In addit…
Off-lattice grand canonical Monte Carlo simulations of the clean diamond (111) surface, based on the effective many-body Brenner potential, yield the $(2\ifmmode\times\else\texttimes\fi{}1)$ Pandey reconstruction in agreement with ab initio calculations and predict the existence of metastable states, very near in ener…
A thermodynamic theory of ferroelectric thin film multilayers is developed. The free energy function is written down using a multilayer model in which c-domain layers of one ferroelectric material alternate with a-domain layers of a second ferroelectric material. We assume that the interfaces are perfectly sharp and t…
This paper describes a novel hydrogel concept, which is based on self-assembling of enantiomeric lactic acid oligomers (stereocomplex formation) grafted to dextran. The hydrogels are prepared in an all-aqueous environment. For this purpose, l - and d -lactic acid oligomers were coupled to dextran, yielding dex−( l )la…
The reflectance of porous silicon carbide (PSC) thin films on SiC substrates is measured in the infrared reststrahlen region by Fourier transform infrared reflectance spectroscopy and is compared to simulated spectra based on phenomenological and Bergman statistical effective-medium dielectric functions. The phenomeno…
Electronic and structural properties of a hypothetical material, silicon nanotubes, are examined through first-principles calculations based on density functional theory. Even considering that Si nanotubes have never been observed, this paper attempts to establish the theoretical similarities between Si and C, like ba…
In metal nanoparticles the resonance wavelength of light-driven collective electron oscillations is determined by the particle shape. This shape dependence can be used for optical data storage by spectral coding. In this way the storage density can be increased by at least a factor of 5 compared with that for conventi…
Recent advances in the theory of polarization and the development of linear-scaling methods have revitalized interest in the use of Wannier functions for obtaining a localized orbital picture within a periodic supercell. To examine complex chemical systems it is imperative for the localization procedure to be efficien…
Size effects in cupric oxide nanocrystals, synthesized using a novel electrochemical route, having average diameters of about 4 and 6 nm, are probed by x-ray photoelectron spectroscopy. Cu---O bond ionicity was found to increase with reduction in nanocrystallite size. Formation of pure CuO phase was confirmed from x-r…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPhotoalignment of Liquid-Crystal SystemsKunihiro IchimuraView Author Information Chemical Resources Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan Cite this: Chem. Rev. 2000, 100, 5, 1847–1874Publication Date (Web):April 15, 20…