Materials Literature
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The $3p$ photoelectron spectra of free Fe and Co atoms have been measured with the use of monochromatized synchrotron radiation and the atomic beam technique. These spectra reveal complex ${3p}^{\ensuremath{-}1}$ multiplet structures, which are discussed based on the predictions of configuration-interaction calculatio…
Based on a detailed consideration of excitation mechanisms of erbium in crystalline and amorphous matrix we present an analysis of the physical meaning of the Auger excitation cross section of ${\mathrm{Er}}^{3+}$ ions in semiconductor. It is demonstrated that large values of Auger excitation cross sections under opti…
The structure and energetics of Ge substitutional defects on the alpha-Sn/Ge(111) surface are analyzed using Density Functional Theory (DFT) molecular dynamics (MD) simulations. An isolated Ge defect induces a very local distortion of the 3x3 reconstruction, confined to a significant downwards displacement (-0.31 A) a…
When an electron tunnels from a metal into the barrier in a magnetic tunnel junction it has to cross the interface. Deep in the metal the eigenstates for the electron can be labelled by the point symmetry group of the bulk but around the interface this symmetry is reduced and one has to use linear combinations of the…
A theoretical study is made of the magnetization versus applied field curves of ferromagnetic/nonmagnetic multilayers constructed according to a Fibonacci quasiperiodic sequence. The ferromagnetic films are assumed to have uniaxial anisotropy and are coupled by both bilinear and biquadratic effective exchange. The eff…
Here we report the growth of sub-millimeter MgB2 single crystals of various shapes under high pressure in Mg-B-N system. Structure refinement using a single-crystal X-ray diffraction analysis gives lattice parameters a=3.0851(5) A and c=3.5201(5) A with small reliability factors (Rw =0.025, R=0.018), which enables us…
Research on the exchange bias (EB) phenomenon has witnessed a flurry of activity during recent years, which stems from its use in magnetic sensors and as stabilizers in magnetic reading heads. EB was discovered in 1956 but it attracted only limited attention until these applications, closely related to giant magnetore…
We find that GeIV substitutes cleanly for AlIII at the central tetrahedral site in the AlO4Al12(OH)24(OH2)127+ polyoxocation, creating a GeO4Al12(OH)24(OH2)128+ cation with some slight structural distortion, but a structure that overall still resembles an ε-Keggin molecule. These substituted aluminum polyoxo molecules…
Electroluminescence detected in many different polymers under uniform 50 Hz ac and dc fields exhibits a threshold-like character, i.e. the light emission increases supralinearly with the applied voltage above a critical value called the emission threshold. The significance of this threshold is not straightforward. It…
The Debye equation with slit-smeared small angle x-ray scattering (SAXS) data is extended from an ideal two-phase system to a pseudo two-phase system with the presence of the interface layer, and a simple accurate solution is proposed to determine the average thickness of the interface layer in porous materials. This…
We present the photoluminescence characterization of pure and 0.2 mol% samarium-doped zirconium oxide, prepared by the sol-gel process and annealed at 1000 °C to stabilize the monoclinic phase. Under excitation at 320 nm the Sm 3+ -doped monoclinic zirconium oxide shows strong emission at the green (569 nm) and red (6…
ZnSe quantum dots have been synthesized using a simple aqueous route. Coating ZnSe quantum dots with a ZnS monolayer, yields a remarkable enhancement in the PL quantum efficiency at room temperature without affecting the spectral distribution. The results suggest that passivation of surface states, along with an incre…
Push−pull organic molecules that combine a polyfunctionalized aromatic electron-donating carbazole moiety with nitro or cyano acceptor groups, linked directly or through a polyenic chain, have been prepared and characterized as nonlinear optical (NLO) chromophores. A methoxycarbonyl group has been introduced to prepar…
Atomic scale imaging using scanning tunneling microscopy has been used to investigate the morphology and structure of high molecular weight polymers attached to carbon nanotubes. A surprising degree of regularity is observed in the attached polymers, suggesting a “nanotube-driven” crystallization process is present. T…
We study morphologies of thin-film diblock copolymers between two flat and parallel walls. The study is restricted to the weak segregation regime below the order-disorder transition temperature. The deviation from perfect lamellar shape is calculated for phases which are perpendicular and parallel to the walls. We exa…
Cd1-xZnxTe crystals with x in the range of 0.1-0.2 were grown by the high-pressure vertical Bridgman method from pre-synthesized CZT. Resistive graphite heaters were used to control the temperature profiles within the furnaces, and an argon overpressure was used to reduce the cadmium loss. The crystals were doped with…
The period from 1970s to 1980s witnessed notable interdisciplinary breakthroughs in sol−gel science with demonstrations that this technology could be extended to the encapsulation of functional biomolecules such as enzymes and antibodies within ceramic matrixes. Since these landmark studies, some of nature's most sens…
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” opt…
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” opt…
Dislocation densities, arrangements and long range internal stresses in cold rolled polycrystalline Cu, Ni, and Al, as well as in cold torsioned Fe, were determined by X-ray diffraction profile analysis using synchrotron radiation. At different deformation degrees, scanning measurements across single grains with a foc…