Materials Literature
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Multimodal contrast agents based on highly luminescent quantum dots (QDs) combined with magnetic nanoparticles (MNPs) or ions form an exciting class of new materials for bioimaging. With two functionalities integrated in a single nanoparticle, a sensitive contrast agent for two very powerful and highly complementary i…
The dynamic glass transition (alpha relaxation, structural relaxation) of ultrathin polysulfone films prepared between aluminum electrodes is investigated by dielectric relaxation spectroscopy. As a main result, it is found that the glass transition temperature Tg does not depend on the thickness of the polymeric laye…
We report confocal microscopy observations of the spatial distribution of monodisperse charge-stabilized colloidal particles (amphoteric polystyrene latex) incorporated within a spinodal-type phase-separating system of mixed biopolymers (gelatin + oxidized starch). Images from samples aged at 40 degrees C demonstrate…
The oxygen vacancy in BiFeO3 is calculated to be a double donor with states 0.6 eV below the conduction band edge, consistent with cathodoluminescence and electronic conductivity data. The atomic configurations were relaxed using the local density approximation plus Hubbard U (LDA+U) to the electron-correlation energy…
Abstract Self‐assembled nanocapsules containing a hydrophilic core and a crosslinked yet thermosensitive shell are successfully prepared using poly(ethylene‐oxide)‐poly(propylene‐oxide)‐poly(ethylene‐oxide) block copolymers, 4‐nitrophenyl chloroformate, gelatin, and 1‐ethyl‐3‐(3‐dimethylaminopropyl) carbodiimide. The…
Delafossite antiferromagnetic oxide ${\text{CuCrO}}_{2}$ was investigated by means of neutron powder diffraction versus temperature. Evolution of the structural parameters (in the $R\overline{3}m$ hexagonal setting) shows a steady decrease in the $a$ lattice parameter but negative thermal expansion along $c$ as the te…
Advances in atomic resolution in situ environmental transmission electron microscopy for direct probing of gas-solid reactions, including at very high temperatures (approximately 2000 degrees C) are described. In addition, recent developments of dynamic real time in situ studies at the Angstrom level using a hot stage…
From measurements of the current-perpendicular-to-plane total specific resistance (AR=area times resistance) of sputtered Pd/Ir multilayers, we derive the interface specific resistance, 2ARPd/Ir=1.02±0.06 fΩ m2, for this metal pair with closely similar lattice parameters. Assuming a single fcc crystal structure with t…
The dispersion of the dielectric function for wurtzite InN is analytically evaluated in the region near the fundamental energy gap. The real part of the dielectric function has a logarithmic singularity at the absorption edge. This results in the large contribution into the optical dielectric constant. For samples wit…
The synthesis of single-wall carbon nanotubes of desired diameters and chiralities is critical to the design of nanoscale electronic devices with desired properties. The existing methods are based on self-assembly, therefore lacking control over the diameters and chiralities. The present work reports a direct route fo…
We introduce a cylindrical cloak to control the bending waves propagating in thin plates. This is achieved through radially dependent isotropic mass density and radially dependent and orthotropic flexural rigidity deduced from a coordinate transformation for the biharmonic propagation equation in the spirit of the pap…
Mn-Anderson based polyoxometalate clusters with different terminal groups have been patterned successfully onto self-assembled monolayer (SAM) using microcontact printing. Studies of the interactions between the designed SAMs and human fibroblast (hTERT-BJ1) cells have been reported, and it was observed that cells att…
We present a three-dimensional simulation and calculation of electrical conductivity above the filler percolation threshold for networks containing finite, conductive cylinders as a function of axial orientation $(S)$ and aspect ratio $(L/D)$. At a fixed volume fraction and $L/D$, the simulations exhibit a critical de…
We have investigated the effect of N doping into Cu2O films deposited by reactive magnetron sputtering. With increasing N-doping concentration up to 3%, the optical bandgap energy is enlarged from ∼2.1 to ∼2.5 eV with retaining p-type conductivity as determined by optical absorption and Hall effect measurements. Addit…
State-of-the-art quantum chemical methods are applied to the study of the multiorbital correlated electronic structure of a Fe-As compound, the recently discovered LiFeAs. Our calculations predict a high-spin, S=2, ground-state configuration for the Fe ions, which shows that the on-site Coulomb interactions are substa…
In this work, the spin relaxation accompanying the spin diffusion in symmetric Si/SiGe quantum wells without the D'yakonov-Perel' spin-relaxation mechanism is calculated from a fully microscopic approach. The spin relaxation is caused by the inhomogeneous broadening from the momentum-dependent spin precessions in spat…
We have investigated systematically the physical transport properties of layered 112-type cobaltite by means of electrical resistivity, magnetoresistance and thermopower measurements. In order to understand the complex transport mechanism of LaBaCo(2)O(5.5), the data have been analysed using different theoretical mode…
We study a model describing electronic transport in a weakly-coupled semiconductor superlattice with a shunting side layer. Key parameters include the lateral size of the superlattice, the connectivity between the quantum wells of the superlattice and the shunt layer, and the conduction properties of the shunt layer.…
The structure of a single-layer graphene on Ru(0001) is compared with that of a single-layer hexagonal boron nitride nanomesh on Ru(0001). Both are corrugated $s{p}^{2}$ hybridized networks and display a $\ensuremath{\pi}$ band gap at the $\overline{\text{K}}$ point of their $1\ifmmode\times\else\texttimes\fi{}1$ Bril…
High storage capacity and a moderate binding strength are two important requirements that must be met for the successful development of hydrogen storage materials. In the present work we demonstrate that optimizing the number and position of dopants, a configuration of eight Li dispersed at the hollow sites above the…