Materials Literature
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Spin and orbital magnetic moments of rhenium in AA′FeReO6 double perovskites (A,A′=Ba, Sr, and Ca) have been directly probed employing x-ray magnetic circular dichroism at the Re L2,3 edges. A considerable orbital magnetic moment is observed in all the compounds studied, which confirm theoretical predictions of unquen…
By means of magnetic susceptibility and specific heat measurements, x-ray and unpolarized neutron diffraction investigations on powder and single-crystal samples, simultaneous long-range antiferromagnetic Fe and Nd ordering in NdFe 3 ( 11 BO 3 ) 4 with R 32 chemical structure has been found at temperatures below T N =…
We study a model for corrosion and passivation of a metallic surface after small damage of its protective layer. The crossover from an initial regime of slow corrosion rate (pit nucleation) to a regime of rapid corrosion (propagation of the pit) takes place at the incubation time. The model is defined in a lattice who…
We have demonstrated experimentally the manipulation of exciton and nuclear spins in a single self-assembled In$_{0.75}$Al$_{0.25}$As/Al$_{0.3}$Ga$_{0.7}$As quantum dot. The oscillation of exciton and nuclear spin polarizations were clearly observed. The switching of the emissions in Zeeman split pair indicates that t…
The stability, electronic and magnetic properties of Fe atoms adsorbed on the self-assembled Bi-dimer lines nanostructure on the H/Si(001) surface are addressed by spin-density functional calculations. Our results show that Fe adatoms are much more stable on sites closer to the Bi nanolines being able to form one-dime…
Soft x-ray magnetic circular dichroism (XMCD) measurements at the Co L2,3 edges of Co-doped rutile TiO2 at room temperature revealed clear multiplet features characteristic of ferromagnetic Co2+ ions coordinated by O2− ions, being in sharp contrast to the featureless XMCD spectrum of Co metal or metallic clusters. The…
We investigate experimentally and theoretically the coalescence dynamics of two spreading droplets on a highly wettable substrate. Upon contact, surface tension drives a rapid motion perpendicular to the line of centers that joins the drops and lowers the total surface area. We find that the width of the growing menis…
For 0.95(Na0.5K0.5)NbO3–0.05BaTiO3 (0.95NKN-0.05BT) ceramics sintered at 1040–1075°C, abnormal grain growth occurred but the grain size decreased when the sintering temperature exceeded 1075°C. The dielectric constant (ϵ3T∕ϵ3), electromechanical coupling factor (kp), and piezoelectric constant (d33) were considerably…
The compound CsH2PO4 has emerged as a viable electrolyte for intermediate temperature (200-300 degrees C) fuel cells. In order to settle the question of the high temperature behavior of this material, conductivity measurements were performed by two-point AC impedance spectroscopy under humidified conditions (p[H2O] =…
The mechanical properties of nanoporous Au have been investigated by uniaxial compression. Micron-sized columns were machined in the surface of nanoporous Au using a focused Ga+ beam and compressed with a flat punch in a nanoindenter. Using scaling laws for foams, the yield strength of the 15nm diameter ligaments is e…
Protein Quaternary Structures (PQS) represent assemblies of protein chains, which are stable in a particular environment. Biological function of many proteins is closely associated with the ability to aggregation or changing the oligomeric state in general. Therefore, PQS are often viewed as Biological Units. Knowing…
An in situX-ray powder diffraction study has shown that cubic modification of (NH4)2SiF6 (cryptohalite) at 0.2-0.3 GPa transforms irreversibly into a trigonal polymorph with cell parameters a = 5.78 A and c = 4.78 A, presumably the previously known bararite, space group P-3m1. The choice of a pressuretransmitting liqu…
JANA2006 is a new version of crystallographic compu-ting system JANA [1] originally developed for incom-mensurately modulated structures. During more than 20 years of development it became widely used unified system for structure analysis of periodic and aperiodic crystals with emphasis on solving difficult structures…
The question of the different roles of cations in metallic Zintl phases has been examined by taking Ba7Ga4Sb9, an electron-rich phase, as a test case. The electronic structure of this solid has been studied by means of a first-principles density functional theory approach and, indeed, the different Ba atoms are found…
A novel method for the formation of nanometer-scale polymer structures via template assisted admicellar polymerization (TAAP) is described. Admicellar polymerization uses a surfactant layer adsorbed on a surface to localize monomer to the surface prior to polymerization of the monomer. Nanostructures are formed by res…
Few examples are known in which chalcogenide clusters are assembled with organic ligands into crystallographically ordered covalent superlattices even though molecular crystals of such clusters have been known for decades. Here by using bifunctional organic ligands as the organizing force, semiconducting tetrahedral c…
The surfaces of organically functionalized, MCM-41-type mesoporous silica nanoparticle materials, prepared by a co-condensation method, were studied by solid-state nuclear magnetic resonance (NMR) spectroscopy following a series of heat treatments between 100 and 400 °C. The surfaces were functionalized with 2,2‘-bipy…
The tripodal alcohol 1,1,1-tris(hydroxymethyl)ethane (H3thme) directs the formation of heptanuclear cobalt metallocycles in which the metal ions are coupled ferromagnetically.
Crystalline SnS wires of micro- and nanometer scale have been synthesized over tin metal foils at room temperature using a simple surfactant-assisted approach. Scanning electron microscopy, transmission electron microscopy, UV−Vis−near infrared (NIR) and Fourier transform infrared (FTIR) spectroscopy were used to char…
In this paper we describe a very simple electroless plating method used to prepare Ag-coated silica beads. Robust Ag nanostructures can be reproducibly fabricated by soaking silica beads in ethanolic solutions of AgNO(3) and butylamine. When the molar ratio of butylamine to AgNO(3) is far below 1.0, distinct nanosized…