Materials Literature
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Ceramics of A 2 FeReO 6 double perovskites have been prepared and studied for A = Ba and Ca. Ba 2 FeReO 6 has a cubic structure (Fm3m) with a 8.0854(1) Å whereas Ca 2 FeReO 6 has a monoclinic symmetry with a 5.396(1) Å, b 5.522(1) Å, c 7.688(2) Å and = 90.4° (P21/n) . The barium compound is metallic from 5 K to 385 K,…
Spectroscopic magnetization induced optical Second Harmonic Generation (MSHG) measurements from a clean Ni(110) surface reveal strong resonance effects near 2.7 eV that can be attributed to the presence of an empty surface state. The good agreement with model calculations shows the potential of MSHG to probe spin pola…
Spin clustering in diluted magnetic semiconductors (DMS) arises from antiferromagnetic exchange between neighboring magnetic cations and is a strong function of reduced dimensionality. Epitaxially-grown single monolayers and abrupt interfaces of DMS are, however, never perfectly two-dimensional (2D) due to the unavoid…
Silver nanoparticles coated with a uniform, thin shell of titanium dioxide are synthesized via a remarkably simple one-pot route, where the reduction of Ag + to Ag 0 and the controlled polymerization of TiO 2 on the surface of silver crystallites take place simultaneously. The prepared dispersions of coated nanopartic…
Two kinds of ionizable groups, namely, diethylamino and sulfonic acid groups, were introduced to a polymer brush by reaction of the epoxy groups of poly(glycidyl methacrylate) grafted onto a porous hollow-fiber membrane with diethylamine and sodium sulfite, respectively. Aminoacylase solution was permeated through the…
Within the general context of homometallic spin-coupled copper(II) dimers, we define the quantity Δ P 2 (Cu), the difference of copper squared spin populations as calculated for the high-spin (i.e., triplet) and broken symmetry spin states. In the specific case of an azido-bridged copper(II) dimer, the antiferromagnet…
Polymer-bound 2,2′-bipyridine cobalt complexes PSBPY-Co, PSBPY-Co-bipy, PSBPY-Co-oxine, and PSBPY-Co-phen (where PSBPY: polystyrene bound-2,2′-bipyridine; bipy: 2,2′-bipyridine; phen: 1,10-phenanthroline) were synthesized and investigated by IR, X-ray photoelectric spectroscopy, thermogravimetry–differential thermal a…
Salts of the donor molecule, bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF or ET), with pentafluorothiomethylsulfonate (SF 5 CX 2 SO 3 -, X = H or F) anions have been prepared. Three phases, β‘ ‘-(ET) 2 SF 5 CH 2 SO 3, β‘-(ET) 2 SF 5 CF 2 SO 3, and β‘ ‘-(ET) 2 SF 5 CHFSO 3 were obtained by electrocrystallization wit…
A major problem in the practical application of antifoams (substances used to avoid undesirable foam) is the gradual loss of their activity in the course of foam destruction. Several experimental methods are combined in the present study to reveal the origin of this phenomenon, usually termed as the antifoam “exhausti…
The effect of crystal lattice disorder on the conductivity and colossal magnetoresistance in La_{1-x}Ca_{x}MnO_{3} (x \approx 0.33) films has been examined. The lattice defects are introduced by irradiating the film with high-energy (\simeq 6 MeV) electrons with a maximal fluence of about 2\times 10^{17} cm^{-2}. This…
We report on sytematic measurements of the low frequency conductivity in aequous supensions of highly charged colloidal spheres. System preparation in a closed tubing system results in precisely controlled number densities between 1E16/m3 and 1E19/m^3 (packing fractions between 1E-7 and 1E-2) and electrolyte concentra…
Wilson's Numerical Renormalization Group method is used to study the paramagnetic ground state of the periodic Anderson model within the dynamical mean-field approach. For the particle-hole symmetric model, which is a Kondo insulator, we find that the lattice Kondo scale T_0 is strongly enhanced over the impurity scal…
X-ray scattering measurements are performed in order to verify % that the mechanism leading to the DC electric field induced $C_{2v}^{19} \to C_{2v}^{\neq 19}$ phase transition in KDP crystal at 119 K is the changing of the local sites symmetries of phosphate group from $C_2$ in the $C_{2v}^{19}$ phase to $C_s$ in the…
The composition and density of surface hydroxyl and carbonate groups on calcite and dolomite after contact at 25 °C with solutions of different pH (3 to 12) and carbonate concentration (10 - 4 ≤ ∑CO 2 ≤ 0.1 M) were monitored by means of diffuse reflectance infrared (DRIFT) spectroscopy. Both for calcite and dolomite,…
Aryloxycarbonylphenyl acrylates and methacrylates were prepared by reacting 4-acryloyloxybenzoyl chloride and 4-methacryloyloxybenzoyl chloride with different phenols. They were homopolymerized using benzoyl peroxide as the initiator at 65°C in dimethylformamide. The polymers were characterized by IR and 1H–NMR spectr…
${}^{55}\mathrm{Mn}$ NMR line shape measurements in ${\mathrm{La}}_{1\ensuremath{-}x}{\mathrm{Ca}}_{x}{\mathrm{MnO}}_{3}$ for $0.20\ensuremath{\le}x\ensuremath{\le}0.50$ provide experimental evidence about the existence of two distinct regions in the $T\ensuremath{-}x$ magnetic phase diagram, where the homogeneous fer…
BaFe 12 O 19 films on (001) sapphire substrates are prepared by laser deposition with in situ heating and postannealing. The properties of the films are analyzed by x-ray diffractometry, vibrating sample magnetometer, atomic force microscopy, and Raman spectroscopy. The relationship among the coercivity, crystalline o…
The composition variations occurring in decaying SF 6 arc plasmas in the presence of atoms released from the vaporization of organic insulators (e.g. Teflon, polyethylene, polypropylene, megelit, nylon), copper, oxygen and water were studied between 12 000 K and 300 K by means of a chemical kinetics model. From the re…
Electronic and ionic structures of lead vacancies in PbTiO3 were studied using an ab initio approach. Even though the lead vacancy is found to be an acceptor with stable charge states ranging from 2- to 4- it does not form a tightly bound defect pair with a double donor oxygen vacancy. The formation of distant and nea…
Nanosize particles (average size ∼12 nm) of mixed ferrite Mn0.65Zn0.35Fe2O4 were prepared by the hydrothermal precipitation route and studied using x-ray diffraction, transmission electron microscopy, differential scanning calorimetry, magnetization measurements, and Mössbauer spectroscopy. The as-prepared sample was…