Materials Literature
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For the first time,we report the effect of pentavalent subtitution at the Mn site of La(0.67)Ca(0.33)MnO(3). The ferromagnetic -metallic ground state modifies to a cluster-glass insulator beyond x=0.03. The observed suppression in the transition temperatures (39K/at.%) is the largest reported for the Mn site subtitute…
The spin-dependent density of states and the density of spin polarization of an InAs-based two-dimensional electron gas with the Rashba spin-orbit coupling under an intense terahertz laser field are investigated by utilizing the Floquet states to solve the time-dependent Schrödinger equation. It is found that both den…
Accurate ab-initio pseudopotential calculations within density functional theory in the LDA approximation have been performed for structural properties and stability of ZnSe/GaAs(001) defected heterostructures. There is a strong experimental evidence that ZnSe/GaAs heterostructures with minimum stacking fault density…
Using a Bayesian approach a general method is developed to assess error bars on predictions made by models fitted to data. The error bars are estimated from fluctuations in ensembles of models sampling the model-parameter space with a probability density set by the minimum cost. The method is applied to the developmen…
Mononuclear gold complexes in zeolite NaY were synthesized from initially physisorbed Au(CH 3 ) 2 (C 5 H 7 O 2 ) and characterized in reactive atmospheres by X-ray absorption and infrared spectroscopies. Under conditions of CO oxidation catalysis at 298 K and 760 Torr in a flow reactor, the gold remained as mononuclea…
Electrophoretically deposited single-wall carbon nanotube (SWCNT) films on optically transparent electrodes are photoelctrochemically active and generate photocurrent upon visible excitation. A low photon-to-current conversion efficiency of 0.15% suggests that most of the photogenerated charge carriers are lost in the…
Microorganisms point the way: The silica cell walls of various diatoms were covalently functionalized with DNA by using straightforward chemical procedures and then used as templates for the sequence-specific assembly and 3D hierarchical arrangement of prefabricated DNA-modified gold nanoparticles. The DNA was used to…
We report on a multiband microscopic theory of many-exciton complexes in self-assembled quantum dots. The single particle states are obtained by three methods: single-band effective-mass approximation, the multiband $k\cdot p$ method, and the tight-binding method. The electronic structure calculations are coupled with…
Magnetic instability in both ultra-pure and carbon-doped MgB2 films is investigated by magneto-optical imaging, transport and bulk magnetization measurements. In the carbon-doped MgB2 thin film, familiar dendritic flux-jump patterns were observed at low temperature as reported in previous experiments. In the ultra-pur…
A new far-field optical microscopy technique capable of reaching nanometer-scale resolution has been developed recently using the in-plane image magnification by surface plasmon polaritons. This microscopy is based on the optical properties of a metal-dielectric interface that may, in principle, provide extremely larg…
We propose a model which could explain some of the unusual magnetic properties observed for the one-dimensional helical spin system $\mathrm{Co}{(hfac)}_{2}\mathrm{N}\mathrm{I}\mathrm{T}\mathrm{Ph}\mathrm{O}\mathrm{Me}$. One of these properties is that the magnetization shows some plateaus if a magnetic field is appli…
Light illumination of thin crystals of CDW conductor TaS$_3$ is found to result in dramatic changes of both linear ($G$) and nonlinear conduction. The increase of $G$ is accompanied by suppression of the collective conduction, growth of the threshold field $E_T$, and appearance of the switching and hysteretic behavior…
We present the computation of structural and polarization for a ferroelectric polymer, specifically, the beta-phase of poly(vinylidene fluoride) or (-CH$_2$-CF$_2$-)$_n$. Two structures have been described in the literature: one containing an undistorted carbon backbone (planar-zigzag) and the other containing alterna…
The layered iodate Cs2I4O11 has been synthesized and characterized. Its hexagonal tungsten oxide-like framework consists of six-membered rings of corner-sharing IO5 polyhedra with three lone pairs pointing inward and three lone pairs pointing outward (depicted for central ring). Capping of the layer by asymmetric IO3…
A novel bottom-up approach to obtain polymer nanocomposites using cubic silsesquioxanes (POSS) nanoparticles as building blocks is reported. The design is based on associative interaction between particles to form ordered nanostructure and limited crystal growth to render anisotropic shapes. Specifically, the affinity…
A DNA microarray-based global transcript profiling of Escherichia coli in response to cold shock showed that in addition to the known cold shock-inducible genes, new genes such as the flagellar operon, those encoding proteins involved in sugar transport and metabolism, and remarkably, genes encoding certain heat shock…
We investigate the viscoelastic properties of an associating rigid rod network: aqueous suspensions of surfactant stabilized single wall carbon nanotubes (SWNTs). The SWNT suspensions exhibit a rigidity percolation transition with an onset of solidlike elasticity at a volume fraction of 0.0026; the percolation exponen…
Prussian blue (PB) nanoparticles protected by organic polymers such as poly(vinylpyrrolidone) (PVP) and poly(diallyldimethylammonium chloride) (PDDA) were prepared. Different experimental conditions (concentrations of Fe ions and feed ratios of Fe to the polymers) have been investigated to control the size of the PB n…
A tube for electrons: Through π–π and Coulomb interactions, a complex is obtained between carbon nanotubes grafted with pyrene+ (1) and the zinc porphyrin complex 2. Photoexcitation of the resulting donor–acceptor assembly is followed by a rapid and efficient charge separation to generate a charge-separated state that…
The quantum de Haas-van Alphen (dHvA) and Shubnikov-de Haas oscillations measured in graphite were decomposed by pass-band filtering onto contributions from three different groups of carriers. Generalizing the theory of dHvA oscillations for 2D carriers with an arbitrary spectrum and by detecting the oscillation frequ…