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We study the competition between sedimentation, gelation, and liquid crystal formation in suspensions of colloidal gibbsite platelets of five different sizes at three ionic strengths. For large particles (with diameters of 350, 420, and 570 nm) sedimentation is initially the most important factor determining the macro…
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The research described in this paper primarily involves mesoscale simulations: dissipative particle dynamics (DPD) of packed assemblies of oriented fibers suspended in a viscous medium. Computer simulations have been performed in order to explore how the aspect ratio and degree of fiber alignment affect the critical v…
Abstract BaO–Ga 2 O 3 –P 2 O 5 glasses containing small concentrations of CuO (ranging from 0 to 0.4 mol%) were prepared. A number of studies, i.e. differential scanning calorimetry, infrared, optical absorption and ESR spectroscopy, magnetic susceptibility and dielectric properties (constant ( ε ′), loss (tan δ ), ac…
A series of 3- and 9-armed dendrons, functionalized at the focal position to quaternary ammonium salts, were synthesized and characterized. The reaction of these ammonium dendrons with the heteropolyacid H(3)PW(12)O(40) in the presence of hydrogen peroxide led to a family of 9- and 27-armed air-stable polyoxometalate…
Femtosecond pump-probe spectroscopy, in the visible spectral range, is used to study fast processes after photoexcitation in quantum confined wurtzite CdSe core and $\mathrm{CdSe}∕\mathrm{CdS}∕\mathrm{ZnS}$ core/shell nanorods. Effective-mass theory is applied to assign the energy levels in linear absorption spectra.…
The oxidized octaethyltetraphenylporphyrin (1, OETPP) and the corresponding newly prepared octaisobutyltetraphenylporphyrin (3, OisoBuTPP) could be isolated from the reaction of OETPPLi2 (or OisoBuTPPLi2) with SOCl2. The X-ray analysis and the characteristic UV-vis spectra of 1 and 3 revealed that these are the first…
Fabrication, characterization, and optical enhancement applications of bimetallic AgAu nanoparticles and nanoshells are reported. Nanoparticles with tunable surface plasmon resonances are synthesized at room temperature and characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, and photon…
The amount of hydrogen present in porous silicon (PS) nanostructures is analyzed in detail. Concentration of atomic hydrogen chemically bound to the specific surface of PS is quantitatively evaluated by means of attenuated total reflection infrared (ATR-IR) spectroscopy and temperature-programmed desorption (TPD) spec…
Local time-resolved measurements of fast reversal of the magnetization of single crystals of Mn12-acetate indicate that the magnetization avalanche spreads as a narrow interface that propagates through the crystal at a constant velocity that is roughly 2 orders of magnitude smaller than the speed of sound. We argue th…
Band dispersions and Fermi surfaces of the three-dimensional Mott-Hubbard system SrVO3 are directly observed by angle-resolved photoemission spectroscopy. An observed spectral weight distribution near the Fermi level (E(F)) shows cylindrical Fermi surfaces as predicted by band-structure calculations. By comparing the…
Transparent Ni-doped SnO 2 thin films grown by the pulsed laser deposition technique on LaAlO 3 , SrTiO 3 as well as R-cut Al 2 O 3 substrates all show room-temperature ferromagnetism (FM). While the Ni-doped SnO 2 films on LaAlO 3 substrates have a large magnetic moment of about 2 µ B /Ni, films grown under the same…
We have theoretically studied acoustic phonon spectra and phonon propagation in rectangular nanowires embedded within elastically dissimilar materials. As example systems, we have considered GaN nanowires with AlN and plastic barrier layers. It has been established that the acoustically mismatched barriers dramaticall…
The effect of treatment conditions on the magnetic and magnetotransport properties of A-site ordered PrBaMn2O6−δ manganites is examined. The parent oxygen-stoichiometric A-site ordered PrBaMn2O6 samples were prepared from oxygen-stoichiometric A-site disordered Pr0.50Ba0.50MnO3 ones by using a 'two-step' synthesis met…
The contrast mechanism for ferroelectric domain imaging via piezoresponse force microscopy (PFM) is investigated. A novel analysis of PFM measurements is presented which takes into account the background caused by the experimental setup. This allows, for the first time, a quantitative, frequency independent analysis o…
Manganese oxide electrodes of nanowire structure are electrochemically synthesized by cyclic voltammetric electrodeposition at room temperature without surfactant, catalyst, or template. Electrode morphology depends on the deposition potential, which greatly influences the electrochemical performances of the capacitor…
An estimated 500 million vehicles worldwide are equipped with an exhaust catalyst that uses platinum group elements (PGE) as the main active components and thus contribute to global PGE emissions. Although PGE emitted from automobile exhaust catalysts were first believed to remain in the roadside environment, we propo…
Room-temperature Mn K-edge extended x-ray absorption fine structure (EXAFS) studies were carried out on La 1− x Sr x MnO 3+δ ( x = 0.1–0.9) compounds. It is found from the detailed EXAFS analysis that the local structure around Mn sites is different from the global structure inferred from x-ray diffraction, especially…
Combining the Su-Schrieffer-Heeger model and the non-equilibrium Green's function formalism, we investigate the negative differential resistance effect in organic spintronics at low temperature and interprete it with a self-doping picture. A giant negative magnetoresistance exceeding 300% is theoretically predicted as…
ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication to the EditorNEXTSuperhydrophobic Surface from Vapor-Induced Phase Separation of Copolymer Micellar SolutionNing Zhao, Qiongdan Xie, Lihui Weng, Shengqing Wang, Xiaoyan Zhang, and Jian XuView Author Information State Key Laboratory of Polymer Physic…