Materials Literature
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Nanostructure is in the focus of science, and advanced scattering methods are significantly contributing to the solution of related questions. This volume includes 19 contributions to the field of polymers and scattering, collected on the occasion of Wilhelm Ruland's 80th anniversary in October 2005. The contributions…
Abstract Lamellae forming diblock copolymer domains can be directed to assemble without defects and in registration with chemically nanopatterned substrates. Initially, thin films of the lamellar poly(styrene‐ b ‐methyl methacrylate) block copolymer form hexagonally close‐packed styrene domains when annealed on chemic…
Increasing operating voltages of insulated gate bipolar transistor (IGBT) modules results in higher demands on electrical insulation capabilities as well as partial discharge resistance. This paper discusses the insulation failure modes observed in high voltage power modules; most critical are water trees, partial dis…
We consider a class of one-dimensional chains of weakly coupled many level systems. We present a theory which predicts energy diffusion within these chains for almost all initial states, if some concrete conditions on their Hamiltonians are met. By numerically solving the time dependent Schrödinger equation, we verify…
Extracellular and intracellular barriers typically prevent non-viral gene vectors from having an effective transfection efficiency. Formulation of a gene delivery vehicle that can overcome the barriers is a key step for successful tissue regeneration. We have developed a novel core-shelled DNA nanoparticle by invoking…
The analysis of the Raman scattering cross section of the radial breathing modes of double-wall carbon nanotubes allowed us to determine the optical transitions of the inner tubes. The Raman lines are found to cluster into species with similar resonance behavior. The lowest components of the clusters correspond well t…
<div class="htmlview paragraph">Biodiesel can be processed by esterification or by biomass-to-liquid (BTL) process. Neste Oil has developed a BTL diesel component NExBTL utilizing a proprietary conversion process for vegetable oils and animal fats.</div> <div class="htmlview paragraph">NExBTL biodies…
We report on a high-performance back-gated carbon nanotube field-effect transistor (CNFET) with a peak transconductance of 12.5 μS and a delay time per unit length of /spl tau//L=19 ps/μm. In order to minimize the parasitic capacitances and optimize the performance of scaled CNFETs, we have utilized a dual-gate design…
A fundamental reworking of pharmacokinetic theory for the use of contrast reagents (CRs) in T(1)-weighted MRI studies is presented. Unlike the standard model in common use, this derivation starts with the quantities measured, the intravascular, interstitial, and intracellular (1)H(2)O signals. The time dependences of…
Spherical SiO2 particles have been coated with Y2O3:Eu3+ phosphor layers (SiO2@Y2O3:Eu3+) by a Pechini sol-gel process. X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, photoluminescence, and cathodoluminescence spectra were utilized to characterize the SiO2@Y2O3:Eu3+ c…
An atomistic approach allowing an accurate and efficient treatment of depolarizing energy and field in any low-dimensional ferroelectric structure is developed. Application of this approach demonstrates the limits of the widely used continuum model (even) for simple test cases. Moreover, implementation of this approac…
Since its invention in 1981, scanning tunnelling microscopy (STM) is well-known for its supreme imaging resolution enabling one to observe atomic-scale structures, which has led to the flourishing of nanoscience. As successful as it is, there still remain phenomena which are observed using STM but are beyond our under…
The influence of vacancies in the $C$ sub-lattice of $MgCNi_{3}$, on its structural, electronic and magnetic properties are studied by means of the density-functional based Korringa-Kohn-Rostoker Green's function method formulated in the atomic sphere approximation. Disorder is taken into account by means of coherent-…
In this paper, we recall various features of non equilibrium granular systems. Clusters with specific properties are found depending on the packing density, going from loose (a granular gas) to sintered (though brittle) polycrystalline materials. The phase space available can be quite different. Unexpected features, w…
A close link between the charge transfer electronic structures and polarity dependent high-TC ferromagnetism of TM2+:ZnO DMSs (TM2+ = 3d ions) is demonstrated. Trends in ferromagnetism across the 3d series of TM2+:ZnO DMSs predicted from their charge transfer energies reproduce experimental trends well. These results…
A practical computational scheme based on time-dependent density functional theory (TDDFT) and ultrasoft pseudopotential (USPP) is developed to study electron dynamics in real time. A modified Crank-Nicolson time-stepping algorithm is adopted, under planewave basis. The scheme is validated by calculating the optical a…
X-ray absorption spectroscopy (XAS), optical reflectance spectroscopy, and the Hall effect measurements were used to investigate the electronic structure in ${\mathrm{La}}_{0.7}{\mathrm{Ce}}_{0.3}\mathrm{Mn}{\mathrm{O}}_{3}$ thin films (LCeMO). The XAS results are consistent with those obtained from $\mathrm{LDA}+U$ c…
A simple model explaining the experimental data on QDs luminescence blinking is suggested. The model does not assume the presence of the long-lived electron traps. The bleaching of the QD luminescence is a result of the Auger assisted radiationless relaxation of the excitation through the deep surface states. Possible…
A new form of P: The crystal structure of a fibrous type of red phosphorus was solved using single-crystal X-ray diffraction methods and transmission electron microscopy. It consists of double tubes (see picture) and is closely related to the structure of Hittorf's phosphorus. Density functional calculations confirm t…
Four reaction parameters and their effects on the formation of cobalt succinate phases were studied by high-throughput methods. In addition to identifying two new phases, we show that higher reaction temperatures lead to products containing less water, more basic conditions favor increasingly condensed M-O-M networks…