Materials Literature
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We carry out extensive molecular dynamics (MD) simulations of translation and rotation of spheroids in the suspension of spheres, for a wide range of values of the aspect ratio, κ ranging from the extreme limits of long rodlike molecules to the disc-shaped ones. While diffusion is anisotropic in short times (compared…
We have performed magnetic and transport measurements on a series of Nd0.67Sr0.33Mn1−xFexO3 polycrystalline compounds with x=0.0, 0.05, 0.10, and 0.15. For the Fe-undoped Nd0.67Sr0.33MnO3 (NSMO) materials, a magnetoresistance (MR) as high as ∼33% was observed at the metal–insulator transition temperature, Tp=273 K, in…
The reactivities of surface oxygen phases on Pd(100) toward reduction by CO were characterized using temperature-programmed desorption and reaction (TPD, TPR), isothermal kinetic measurements, low energy electron diffraction (LEED), and scanning tunneling microscopy (STM). When CO was exposed to high oxygen coverages…
ADVERTISEMENT RETURN TO ISSUEPREVNoteNEXTLamellar Alignment of Diblock Copolymers in an Electric FieldA. V. Kyrylyuk, A. V. Zvelindovsky, G. J. A. Sevink, and J. G. E. M. FraaijeView Author Information Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands Cite this: Macromole…
We measured high spatial/depth resolution 300 K thermal conductivity κ of the Zn and O surfaces of two bulk n-type ZnO (0001) samples, grown by a vapor-phase transport method, using scanning thermal microscopy (SThM). The thermal investigation was performed in both point-by-point (∼2 μm resolution) and area-scan modes…
The crystalline orbitals of seven oxygen containing compounds with increasing degree of covalent character (MgO, MnO, ZnO, Al2O3, SiO2, AlPO4, and CaSO4) are localized according to a Wannier–Boys mixed scheme recently implemented. The resulting Wannier functions are analyzed in terms of various indices (centroids posi…
We have studied the structural and transport properties of Sb2Te3 thin films prepared by molecular beam epitaxy as a function of the Te/Sb flux ratio during deposition. Both the crystallinity and the transport properties are found to be strongly affected by nonstoichiometry. The most stoichiometric sample (prepared wi…
A methodology for the theoretical evaluation of Raman intensities for a molecule adsorbed on a metal particle aggregate, possibly in the presence of a solvent, is presented. The molecule is treated at the ab initio level, both in the evaluation of ground state electronic density and nuclear geometry, and in the evalua…
We have studied the structural properties of ZnO thin films grown on Al2O3 (00.1) single-crystal substrates by pulsed-laser deposition using either a femtosecond or a nanosecond laser. Although hexagonal ZnO films deposited on sapphire substrate were epitaxially grown in both cases, the crystalline quality was found t…
Using molecular simulations and free energy calculations based on Landau theory, we show that freezing/melting behavior of fluids of small molecules in pores of simple geometry can be understood in terms of two main parameters: the pore width H* (expressed as a multiple of the diameter of the fluid molecule) and a par…
Abstract The nonisothermal crystallization kinetics of poly(propylene) (PP) and poly(propylene)/organic‐montmorillonite (PP/Mont) nanocomposite were investigated by differential scanning calorimetry (DSC) with various cooling rates. The Avrami analysis modified by previous research was used to describe the nonisotherm…
Nanoribbons and flat nanosheets of Ga 2 O 3 have been synthesized by evaporating GaN at high temperature with the presence of oxygen. The as-synthesized nanoribbons and nanosheets are pure, structurally uniform, single crystalline, and free from dislocations. The nanoribbons and the nanosheets all have monoclinic β-Ga…
The azomethine ylide generated from the reaction of (beta-formyl-meso-tetraphenylporphyrinato)nickel(II) with N-methylglycine reacts with a range of dipolarophiles, yielding new beta-substituted-meso-tetraphenylporphyrins. The regio- and stereochemistry of the new compounds was established using one- and two-dimension…
We discuss the BCS-BEC crossover in a degenerate Fermi gas of two hyperfine states interacting close to a Feshbach resonance. This system has quasi-molecular Bosons associated with a Feshbach resonance, and this kinds of coupled Boson-Fermion model has been recently applied to Fermi atomic gases within a mean-field ap…
We studied the crystal and magnetic structure of the ${\mathrm{La}}_{1\ensuremath{-}x}{\mathrm{Ca}}_{x}{\mathrm{MnO}}_{3}$ compound for $x=0.8$ and $x=0.85.$ At $T=300 \mathrm{K}$ both samples are paramagnetic with crystallographic symmetry $\mathrm{Pnma}.$ At low temperatures they undergo a monoclinic distortion from…
The characteristics of PVC pyrolysis dechlorination has been studied in a fixed bed reactor under different operating conditions such as temperature, time, heating rate. It is found that about 90% chlorine in PVC can be effectively removed within 3 h with heating rate of 5 μ/min at temperature 300 °C, with 10% chlorin…
A series of ZnO films with various thicknesses were prepared on (0001) sapphire substrate by pulsed laser deposition (PLD). Scanning electron microscopy (SEM) and x-ray diffraction (XRD) analysis were utilized to investigate the effects of thickness variation on the surface morphology and the crystallinity. The electr…
A series of axial and equatorial diastereomers of (coumarin-4-yl)methyl-caged adenosine cyclic 3',5'-monophosphates (cAMPs), 1-6, having methoxy, dialkylamino, or no substituent in the 6- and/or 7-positions, and their corresponding 4-(hydroxymethyl)coumarin photoproducts 7-12 have been synthesized. The photochemical a…
We propose a method to determine the direction of surface magnetization and local magnetic moments on the atomic scale. The method comprises high resolution scanning tunneling microscope experiments in conjunction with first principles simulations of the tunneling current. The potential of the method is demonstrated o…
The acoustic emission of fracture precursors, and the failure time of samples of heterogeneous materials (wood, fiberglass) are studied as a function of the load features and geometry. It is shown that in these materials the failure time is predicted with a good accuracy by a model of microcrack nucleation proposed by…