Materials Literature
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High-quality Co 2 P nanoparticles have been obtained from diphosphine-substituted molecular cobalt clusters anchored into an inorganic matrix. The synthesis was followed stepwise using a wide panel of analytic techniques. The required functionalization of an ordered mesoporous silica matrix of the type SBA-15 was achi…
Cofacial palladium(II) bisporphyrins anchored by xanthene [Pd 2 (DPX)] and dibenzofuran [Pd 2 (DPD)] pillars were prepared, and the dynamics of their triplet excited states were investigated. The phosphorescence quantum yield [ Φ p = 4.59(121) × 10 -3 in CH 2 Cl 2 ] and lifetime [ τ p = 18.2(2) μs in CH 2 Cl 2 ] of Pd…
We propose a Landauerlike theory for nonlinear transport in networks of one-dimensional interacting quantum wires (Luttinger liquids). A concrete example of current experimental focus is given by carbon nanotube Y junctions. Our theory has three basic ingredients that allow one to explicitly solve this transport probl…
Molecular dynamics simulations of bulk atactic polystyrene have been performed in a temperature range from 100 to 650 K at atmospheric pressure. Local translational mobility has been investigated by measuring the mean square translational displacements of monomers. The long-time asymptotic slope of these dependencies…
The first examples of a new mesoporous form of crystalline AlOOH (boehmite) were prepared using aluminum sec -butoxide as the alumina precursor and an amine surfactant as a hierarchical structure director. The hydrolysis of the alkoxide in the presence of various amine surfactants at ambient temperature afforded boehm…
The effect of axial ligation on the photoinduced charge separation and charge recombination of a series of covalently linked porphyrin−C 60 dyads is investigated. Toward this, meso -tetraphenylporphyrin and its zinc(II) derivative are functionalized at the ortho or para positions of one of the aryl groups to bear a fu…
In the absence of a corrosive environment, brittle materials such as silicon should be immune to cyclic fatigue. However, fatigue effects are well known in micrometer-sized polycrystalline silicon (polysilicon) samples tested in air. To investigate the origins of this phenomenon in polysilicon, we developed a fixed-gr…
Nanoribbons of Cu(OH) 2 have been synthesized by coordination self-assembly in solution. Techniques of XRD, TEM, HRTEM, SEM, ED, EDX, and XPS have been used to characterize the morphology, structure, and composition of the nanoribbons. The Cu(OH) 2 nanoribbons are 20−100 nm in width, several nm in thickness, and up to…
Methods of making mesostructured sol-gel silicate thin films containing two different molecules deliberately placed in two different spatially separated regions in a one-step, one-pot preparation are developed and demonstrated. When the structure-directing agent is the surfactant cetyltrimethylammonium bromide, the st…
We construct a rejection-free Monte Carlo algorithm for a system with continuous degrees of freedom. We illustrate the algorithm by applying it to the classical three-dimensional Heisenberg model with canonical Metropolis dynamics. We obtain the lifetime of the metastable state following a reversal of the external mag…
We describe novel excitons in quantum dots by allowing for an interaction with a Fermi sea of electrons. We argue that these excitons can be realized very simply with self-assembled quantum dots, using the wetting layer as host for the Fermi sea. We show that a tunnel hybridization of a charged exciton with the Fermi…
Optically-controlled exciton dynamics in coupled quantum dots is studied. We show that the maximally entangled Bell states and Greenberger-Horne-Zeilinger (GHZ) states can be robustly generated by manipulating the system parameters to be at the avoided crossings in the eigenenergy spectrum. The analysis of population…
Measurements of the electrical and thermal conductivities, thermopower and paramagnetic susceptibility have been performed on single crystal samples of Bi1/2Sr1/2MnO3 and complemented with the X-ray powder diffraction data. A pronounced hysteretic behavior, observed below the cubic-to- orthorhombic transition at Tcrit…
Starting from a simple microscopic model, we have derived a kinetic equation for the matrix distribution function. We employed this equation to calculate the conductance $G$ in a mesoscopic F'/F/F' structure with a domain wall (DW). In the limit of a small exchange energy $J$ and an abrupt DW, the conductance of the s…
We show that the critique of our recent papers presented in the abovementioned paper (NS) appeals to an incorrect mathematical analogy between electrical circuits and linear magnetization dynamics, improperly uses classical concepts of normal modes and basic equations, gives inconsistent results and therefore comes to…
Three-coordinate organometallic complexes are rare, especially with the prototypical methyl ligand. Using a hindered, rigid bidentate ligand (L), it is possible to create 12-electron methyliron(II) and 13-electron methylcobalt(II) complexes. These complexes are thermally stable, and (1)H NMR spectra suggest that the l…
We review synthesis, structural characterization, and catalysis by supported bimetallic clusters. Initial steps in the preparations include (a) adsorption of molecular metal clusters with preformed metal−metal bonds; (b) synthesis in zeolite cages; and (c) adsorption of a metal complex on a supported complex or cluste…
Opinion has long been divided as to whether the Mg/Ca ratio of seawater remained constant during the Phanerozoic or underwent substantial secular change. Existing empirical evidence for the Mg/Ca of ancient seawater provides a poorly resolved and often controversial signal. Echinoderm fossils that have retained their…
We present a rationalization of the Raman spectra of orthorhombic and rhombohedral, stoichiometric and doped, manganese perovskites. In particular, we study $R{\mathrm{MnO}}_{3}$ $(R=\mathrm{La},$ Pr, Nd, Tb, Ho, Er, Y, and Ca) and the different phases of Ca- or Sr-doped $R{\mathrm{MnO}}_{3}$ compounds as well as cati…
A new class of organic nanoparticles (CN-MBE nanoparticles) with a mean diameter of ca. 30-40 nm, which exhibit a strongly enhanced fluorescence emission, were prepared by a simple reprecipitation method. CN-MBE (1-cyano-trans-1,2-bis-(4'-methylbiphenyl)ethylene) is very weakly fluorescent in solution, but the intensi…