Materials Literature
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Eingefangen: Ein Octasilsesquioxan mit einem Fluoridion als Gast wurde kristallstrukturanalytisch charakterisiert (siehe Bild). Struktur- und NMR-spektroskopischen Daten zufolge ist das eingeschlossene Fluoridion im Wesentlichen „nackt“. Da die Si-F-Wechselwirkungen nur schwach sind, weicht die Geometrie der Käfigverb…
The pressure effect on magnetic order and anisotropy of low-doped ${\mathrm{LaMnO}}_{3.05}$ single crystals with two competing ferromagnetic and antiferromagnetic insulating phases was studied by magnetization measurements. It was found that applied hydrostatic pressure leads to an increase of both Curie and N\'eel te…
We report a theoretical study on the effects of O 2 adsorption at tips of single-wall carbon nanotubes for capped and uncapped geometries. Adsorption mechanisms that take place at the tip, also including the effects of an electric field, are described, highlighting configurations that alter emission properties. Change…
ADVERTISEMENT RETURN TO ISSUECommunicationNEXTPhotochemically Driven Smectic−Cholesteric Phase Transition in an Inherently Photoactive DimesogenV. Ajay Mallia and Nobuyuki TamaokiView Author Information National Institute of Advanced Industrial Science and Technology (AIST), Central 5, Higashi 1-1-1, Tsukuba, Ibaraki…
The nanosized icosahedral-based cluster [Pd69(CO)36(PEt3)18] (see picture) exhibits two new salient stereochemical features: 1) a linear face-condensation of three centered icosahedra that gives rise to a linear face-sharing Pd33-centered triicosahedron, and 2) a hexagonal-shaped Pd30 tube formed by cyclic trans edge-…
Three novel narrowly distributed rod−coil diblock copolymers, poly(styrene- block -(2,5-bis[4-methoxyphenyl]oxycarbonyl)styrene) (PS- b -PMPCS), with same PS block length and different PMPCS lengths, were synthesized by 2,2,6,6-tetramethyl-1-piperidinyloxy- (TEMPO-) mediated living free radical polymerization. The sel…
A global picture for the structural evolution in the relaxor-ferroelectric solid solution $({\mathrm{PbSc}}_{1/2}{\mathrm{Nb}}_{1/2}{\mathrm{O}}_{3}{)}_{1\ensuremath{-}x}\ensuremath{-}({\mathrm{PbTiO}}_{3}{)}_{x}$ is proposed. Thanks to x-ray profile analysis and Rietveld neutron powder refinement, a monoclinic phase…
We have successfully measured the sliding force for an interlayer of individual multiwall carbon nanotubes using a combination of a well-controlled electrical breakdown process and a manipulation process using a scanning electron microscope. A sliding force of ∼4 nN for an inner layer diameter of 5 nm is maintained co…
We present a theory of the anomalous Hall effect in ferromagnetic $(\mathrm{G}\mathrm{a},\mathrm{M}\mathrm{n})\mathrm{A}\mathrm{s}$ in the regime when conduction is due to phonon-assisted hopping of holes between localized states in the impurity band. We show that the microscopic origin of the anomalous Hall conductiv…
Bubble levitation in an acoustic standing wave is re-examined for conditions relevant to single-bubble sonoluminescence. Unlike a previous examination [Matula et al., J. Acoust. Soc. Am. 102, 1522-1527 (1997)], the stable parameter space [Pa,R0] is accounted for in this realization. Forces such as the added mass force…
The structures, magnetisms, and magneto-optical (MO) Kerr spectra of nanocrystalline ${\mathrm{CoFe}}_{2\ensuremath{-}x}{M}_{x}{\mathrm{O}}_{4}$ $(M=\mathrm{M}\mathrm{n},\mathrm{A}\mathrm{l},\mathrm{S}\mathrm{c})$ thin films have been systematically investigated by means of x-ray diffraction, atomic force microscopy,…
A series of organically modified clays (OMCs) with a surfactant loading range from 0.625 to 2.5 times the cation exchange capacity (CEC) were melt-mixed with maleated polypropylene (PPMA). Wide-angle X-ray diffraction and transmission electron microscopy results of these nanocomposites show that dispersion of clays be…
Optical and electron-spin resonance (ESR) spectroscopy studies of low-temperature electron-irradiated amorphous ${\mathrm{SiO}}_{2}$ were carried out to identify optical transitions of self-trapped holes (STHs). Spectroscopic analysis by means of polarized optical bleaching and thermal annealing has revealed two compo…
ADVERTISEMENT RETURN TO ISSUEPREVNoteSynthesis and Characterization of Anionic and Cationic Poly(ferrocenylsilane) PolyelectrolytesMark A. Hempenius, Fabiane F. Brito, and G. Julius VancsoView Author Information MESA+ Research Institute for Nanotechnology, University of Twente, P.O. Box 217, NL-7500 AE Enschede, The N…
The purpose of this research was to study the influence of the temperature, treatment time, and initial coal particle size on the evolution of the structural order of graphite materials that have been prepared from an anthracite at temperatures >2273 K. Crystalline parameters such as the interlayer spacing and crystal…
A $\ensuremath{\pi}$-electron network in nanographite systems with zigzag edges exhibits strongly localized edge states, which are expected to have peculiar properties. We study effects of electron-electron interactions on ground-state properties of zigzag nanographite ribbons and open-ended zigzag nanotubes by means…
First-principles density-functional calculations are performed within the local-density approximation to study the electronic properties of ${\mathrm{SrZrO}}_{3},$ an insulating $4d$ perovskite, in its high-temperature cubic phase, above 1400 K, as well as the generic $3d$ perovskite ${\mathrm{SrTiO}}_{3},$ which is a…
Four {SiW9O34} units enclose a 14 CuII cluster obtained through halide supramolecular assembly, leading to the polyanion containing the highest number of divalent metal cations (see picture; W blue, Si yellow, Br orange, Cu green, O red).
Giving color to data recording: Upon irradiation with selected wavelengths of light the hexane solution of a fused dithienylethene derivative changes from colorless to yellow, green, black, or blue depending on the wavelength, and irradiation time (see picture). This could be a landmark in the development of new data…
Taming the caged ion: The X-ray crystal structure of an octaphenyl octasilsesquioxane cage that encapsulates a fluoride ion is presented (see picture). The extent of the SiF interaction is low, which causes the cage geometry to not change significantly from that of a normal T8 structure. The crystal structure and the…