Materials Literature
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We present a growth technique which combines wet-chemical growth and molecular beam epitaxy (MBE) to create complex semiconductor nanostructures with nanocrystals as active optical material. The obtained results show that wet-chemically prepared semiconductor nanocrystals can be incorporated in an epitaxally grown cry…
Freestanding Ge nanocrystals that are stable under ambient conditions have been synthesized in a two-step process. First, nanocrystals with a mean diameter of 5nm are grown in amorphous SiO2 by ion implantation followed by thermal annealing. The oxide matrix is then removed by selective etching in diluted HF to obtain…
Synthesis, characterizations, and photophysical properties of new photoactive dyads and triads containing perylenetetracarboxylic diimide (PIm) and porphyrin (free-base porphyrin (H(2)P) and zinc porphyrin (ZnP)), in which both entities were connected with a short ether bond, were examined with the aim of using these…
This communication describes a new synthetic approach to one- (1D) and two-dimensional (2D) NbSe2 nanoscale materials using soft chemical methods. Our one-pot synthesis provides a direct route to control the morphology of nanostructures that can exhibit complex electronic properties, and can produce layered, nanocryst…
The recent observation of pyroelectricity in quasiamorphous thin films of $\mathrm{Ba}\mathrm{Ti}{\mathrm{O}}_{3}$ introduced a previously unreported type of polar ionic solid where the appearance of a macroscopic dipole moment is not accompanied by long-range crystal-like order. This poses a question regarding the me…
Bacillus subtilis gene products TenA and TenI have been implicated in regulating the production of extracellular proteases, but their role in the regulation process remains unclear. The structural characterization of these proteins was undertaken to help provide insight into their function. We have determined the stru…
In this study we demonstrate that one-dimensional (1D) nanostructured lead telluride (PbTe) can be synthesized in a hydrothermal reaction between lead foil and tellurium powder. The resulting materials were characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The form…
Polyelectrolyte multilayer (PE) deposition and S-layer technology have been combined to make novel robust biomimetic surfaces and membranes. Isolated subunits of the bacterial cell surface layer from Bacillus sphaericus CCM2177 SbpA was self-assembled on PE multilayer supports, with the composition of the multilayer p…
Epitaxial cuprous oxide nanostructures with high aspect ratio were deposited electrochemically on n-InP(111) from aqueous solution at room temperature. High-resolution X-ray diffraction shows that the Cu 2 O and InP form three equivalent epitaxial orientation relationships that are rotated 120° relative to each other:…
Two-dimensional computational fluid dynamics (CFD) simulations are used to study spatially segregated, multifunctional, microchemical devices for hydrogen production. In particular, coupling between homogeneous propane combustion and catalytic ammonia decomposition on a Ru catalyst is studied in a microdevice consisti…
Highly ordered 3D mesostructures of ceria have been obtained by a block-copolymer-assisted assembly of near-monodisperse, highly crystalline ceria nanoparticle sols. The preformed ceria nanoparticles have a diameter of ≈3 nm and are stable in solution without any organic functionalization. The mesoporous materials wer…
The field-emission properties of tungsten oxide nanorods have been shown to depend on phase structure. For example, the turn-on field of WO2.9 nanorods could be as low as 1.2 V μm−1, while that of WO2 nanorods (see picture) was above 7 V μm−1. Thus, the field-emission properties can be tuned by rational control of the…
Incompletely condensed, fluorinated polyhedral oligomeric silsesquioxane with the highly reactive group of trisodium silanolate was used for the synthesis of an initiator for atom transfer radical polymerization. The initiator was applied to solution polymerization of methyl methacrylate (MMA) in the presence of a cop…
A new, practical approach to a variety of highly electrooptically active polymers for device development is described. It involves the use of a new thermally cross-linkable, hyperbranched oligomer containing nonlinear optical (NLO) chromophores as a macromolecular dopant in a common host polymer. A series of NLO polym…
Multiple small samples of amorphous silica have been generated and optimized using classical dynamics and the van Beest-Kramer-van Santen (BKS) empirical potential function. The samples were subsequently optimized and annealed using density functional theory (DFT) with both the local density and the generalized gradie…
Master curves of the relaxation time, $\ensuremath{\tau}$, or viscosity, $\ensuremath{\eta}$, versus ${T}^{\ensuremath{-}1}{V}^{\ensuremath{-}\ensuremath{\gamma}}$, where $T$ is temperature, $V$ the specific volume, and $\ensuremath{\gamma}$ a material constant, are used to deduce the effect of pressure on the dynamic…
We used high order harmonics of a femtosecond titanium-doped sapphire system (pulse duration 25 fs) to realise Ultraviolet Photoelectron Spectroscopy (UPS) measurements on diamond. The UPS spectra were measured for harmonics in the range 13 to 27. We also made ab initio calculations of the electronic lifetime of condu…
Visible and near-infrared extinction spectra of regular arrays of gold nanorods display several bands depending on polarization of the electromagnetic incident field. When setting the incident field perpendicular to the nanorod axis (transverse polarization), a single band is observed, which is assigned to a dipolar p…
The methods of density-functional perturbation theory may be used to calculate various physical response properties of insulating crystals including elastic, dielectric, Born charge, and piezoelectric tensors. These and other important tensors may be defined as second derivatives of the total energy with respect to at…
We describe the synthesis of novel monocrystalline FeCo nanowires encapsulated inside multiwalled carbon nanotubes (MWNTs). These FeCo nanowires exhibit homogeneous Fe and Co concentrations and do not contain an external oxide layer due to the presence of insulating nanotube layers. The method involves the aerosol the…